In this study, nine high-lysine maize kernels and two kernels of common maize hybrid were used as experiment materials, and quantitative determination of lysine contents in high-lysine maize kernels and common maize k...In this study, nine high-lysine maize kernels and two kernels of common maize hybrid were used as experiment materials, and quantitative determination of lysine contents in high-lysine maize kernels and common maize kernels was carried out using Hitachi L-8900 Automatic Amino-acid Analyzer, to know the effect of the Analyzer in distinguishing the lysine contents between common maize kernels and high-lysine maize kernels. The results showed that the lysine contents of high-lysine maize kernels were among 0.34%-0.42%, while of common maize kernels were a- mong 0.24%-0.25%, and the difference was significant. Compared with other tradi- tional methods, this method is rapid, simple, sensitive, highly reproductive and needs fewer maize kernels, thus it is applicable in maize breeding.展开更多
The polymerase acidic protein is an important family of proteins from influenza A virus, which is classified as many different subtypes or spe-cies. Thus, an important question is if these classifications are numerica...The polymerase acidic protein is an important family of proteins from influenza A virus, which is classified as many different subtypes or spe-cies. Thus, an important question is if these classifications are numerically distinguishable with respect to the polymerase acidic protein. The amino-acid pair predictability was used to transfer 2432 polymerase acidic proteins into 2432 scalar data. The one-way ANOVA found these polymerase acidic proteins distinguish-able in terms of subtypes and species. However, the large residuals in ANOVA suggested a pos-sible large intra-subtype/species variation. Therefore, the inter- and intra-subtype/species variations were studied using the model II ANOVA. The results showed that the in-tra-subtype/species variations accounted most of variation, which was 100% in total for both inter- and intra- subtype/species variations. Our analysis threw lights on the issue of how to de-termine a wide variety of patterns of antigenic variation across space and time, and within and between subtypes as well as hosts.展开更多
The mutation pattern in protein is a very important feature and is studied through various approaches including the study on mutation pattern in domains where amino acids are converted into numbers from letters. In th...The mutation pattern in protein is a very important feature and is studied through various approaches including the study on mutation pattern in domains where amino acids are converted into numbers from letters. In this study, we converted the amino acids in human adrenoleukodystrophy protein with its 128 missense mutations into random domain using the amino-acid pair predictability, and then we studied their mutation patterns. The results show 1) the mutations are more likely to target the amino-acid pairs whose actual frequency is larger than their predicted one, 2) the mutations are more likely to form the amino-acid pairs whose actual frequency is smaller than their predicted frequency, 3) mutations are more likely to occur at unpredictable amino-acid pairs, and 4) mutations have the trend to narrow the difference between predicted and actual frequencies of amino-acid pairs.展开更多
A formalin-treated polyvinyl-alcohol (PVF) sponge is convenient as a scaffold because its configuration is easily modified. However, coating the sponge with an adhesive chemical agent is necessary to attach bone marro...A formalin-treated polyvinyl-alcohol (PVF) sponge is convenient as a scaffold because its configuration is easily modified. However, coating the sponge with an adhesive chemical agent is necessary to attach bone marrow cells (BMCs) to the sponge structure. Moreover, it was considered that a hybrid scaffold composed of a sponge and enveloped cylindrical porous hydroxyapatite (HA) would be convenient. In this study, the effect of leucine (Leu) coating on a PVF sponge was examined for osteogenesis on an HA/PVF hybrid scaffold by rat BMCs (rBMCs). In an in vivo assessment, the sponge immersed in Leu solution (10 mg/ml) was inserted into the hollow center of cylindrical HA. The sponge received 1.5 × 106 rBMCs obtained from male Fischer 344 rats. The hybrid scaffolds were then implanted subcutaneously of syngeneic rats for 6 weeks. In vitro assessment of Leu to hard tissue formation with coating on the well or addition in rBMC culture medium was also performed in a 6-well plate for 2 weeks. In vivo examinations showed the excellent effect of Leu coating on PVF sponge. Leu-coated PVF sponge in the scaffolds showed marked new bone formation in the pores by histological examination. Leu-coated PVF sponge showed a high quantity of osteocalcine (OC). HA might prevent the release of rBMCs from PVF as a barrier. In in vitro examinations, the quantity of OC in rBMC culture with and without the addition of Leu in culture medium showed no significant difference. However, addition of Leu showed significant ALP activity level in culture medium. Leu coating in culture plate wells showed no influence on the quantity of OC. It was concluded from the results that Leu might prevent the emigration of rBMCs to the outside of the scaffold and promote the differentiation of cells to osteoblasts in the scaffold.展开更多
Geometry optimization at the B3LYP/6-31＋＋G＊ level of theory has been undertaken on clusters containing L-Met （L-methionine） or L-Cys （L-cysteine） surrounded by eight water molecules. The comparison of the struc...Geometry optimization at the B3LYP/6-31＋＋G＊ level of theory has been undertaken on clusters containing L-Met （L-methionine） or L-Cys （L-cysteine） surrounded by eight water molecules. The comparison of the structural parameters of L-Met and L-Cys with X-ray experimental values is in good agreement within 4.8%. This result shows that the privileged positions of water molecules and the possible hydrogen bonding network formed around the backbone of both AAs （amino acids） are adequate. Subsequent calculations of the harmonic vibrational modes followed by a post-processing treatment enable us to assign the vibrational modes of L-Met and L-Cys surrounded explicitly by eight water molecules. The frequencies of the assigned modes are in good agreement with available IR （infra red） and Raman values within 5%.展开更多
The two waves period of the COVID-19 pandemic saw the use of hydro- alcoholic gel and the consumption of capsules containing improved traditional remedies. At one point, there was a stock-out and a price increase...The two waves period of the COVID-19 pandemic saw the use of hydro- alcoholic gel and the consumption of capsules containing improved traditional remedies. At one point, there was a stock-out and a price increase forthese products. Furthermore, in the food industry, the catering industry adopts gelatin in its current practice. Pig gelatin dominates the international market. And for some religious practices, pork is forbidden and yet these people consume them without taking notice. The production of gelatin from broiler feet seems economically viable because broiler feet are considered slaughterhouse waste that is sold at very low prices. The poultry industry has seen an increase in broiler farming over the last twenty years. However, the latter has all the characteristics required for the production of gelatin. It will therefore comply with the standards of use described in the international codex oenological for gelatins. Physical and chemical analyses such as, ash content, moisture content, and pH measurements were done for the extracted gelatins. Sensible elements are checked with ED XRF spectroscopy. All the results were good and showed without any doubt that broiler gelatin is edible.展开更多
Surfactant flooding is an important technique used to improve oil recovery from mature oil reservoirs due to minimizing the interfacial tension(IFT)between oil and water and/or altering the rock wettability toward wat...Surfactant flooding is an important technique used to improve oil recovery from mature oil reservoirs due to minimizing the interfacial tension(IFT)between oil and water and/or altering the rock wettability toward water-wet using various surfactant agents including cationic,anionic,non-ionic,and amphoteric varieties.In this study,two amino-acid based surfactants,named lauroyl arginine(L-Arg)and lauroyl cysteine(L-Cys),were synthesized and used to reduce the IFT of oil–water systems and alter the wettability of carbonate rocks,thus improving oil recovery from oil-wet carbonate reservoirs.The synthesized surfactants were characterized using Fourier transform infrared spectroscopy and nuclear magnetic resonance analyses,and the critical micelle concentration(CMC)of surfactant solutions was determined using conductivity,pH,and turbidity techniques.Experimental results showed that the CMCs of L-Arg and L-Cys solutions were 2000 and 4500 ppm,respectively.It was found that using L-Arg and L-Cys solutions at their CMCs,the IFT and contact angle were reduced from 34.5 to 18.0 and15.4 mN/m,and from 144°to 78°and 75°,respectively.Thus,the L-Arg and L-Cys solutions enabled approximately 11.9%and 8.9%additional recovery of OOIP(original oil in place).It was identified that both amino-acid surfactants can be used to improve oil recovery due to their desirable effects on the EOR mechanisms at their CMC ranges.展开更多
AIM: To investigate the characteristics of mucosal le-sions and their relation to laboratory data and long-term follow up in breast-fed infants with allergic colitis. METHODS: In this study 31 breast-fed infants were ...AIM: To investigate the characteristics of mucosal le-sions and their relation to laboratory data and long-term follow up in breast-fed infants with allergic colitis. METHODS: In this study 31 breast-fed infants were prospectively evaluated (mean age, 17.4 wk) whose rectal bleeding had not ceased after a maternal elimi-nation diet for cow's milk. Thirty-four age-matched and breast-fed infants (mean age, 16.9 wk) with no rectal bleeding were enrolled for laboratory testing as con-trols. Laboratory findings, colonoscopic and histological characteristics were prospectively evaluated in infants with rectal bleeding. Long-term follow-up with differ-ent nutritional regimes (L-amino-acid based formula or breastfeeding) was also included. RESULTS: Iron deficiency, peripheral eosinophilia andthrombocytosis were significantly higher in patients with allergic colitis in comparison to controls (8.4±3.2 μmol/L vs 13.7±4.7 μmol/L, P<0.001; 0.67±0.49 G/L vs 0.33±0.17 G/L, P<0.001; 474±123 G/L vs 376±89 G/L, P<0.001, respectively). At colonosco-py, lymphonodular hyperplasia or aphthous ulceration were present in 83% of patients. Twenty-two patients were given L-amino acid-based formula and 8 contin-ued the previous feeding. Time to cessation of rectal bleeding was shorter in the special formula feeding group (mean, 1.4 wk; range, 0.5-3 wk) when com-pared with the breast-feeding group (mean, 5.3 wk; range, 2-9 wk). Nevertheless, none of the patients ex-hibited rectal bleeding at the 3-mo visit irrespective of the type of feeding. Peripheral eosinophilia and cessa-tion of rectal bleeding after administration of elemental formula correlated with a higher density of mucosal eosinophils. CONCLUSION: Infant hematochezia, after cow's milk allergy exclusion, is generally a benign and probably self-limiting disorder despite marked mucosal abnor-mality. Formula feeding results in shorter time to cessa-tion of rectal bleeding; however, breast-feeding should not be discouraged in long-lasting hematochezia.展开更多
Synthetic polymer hydrogel nanoparticles(NPs)were developed to function as abiotic affinity reagents for fibrinogen.These NPs were made using both temperature-sensitive N-isopropyl acrylamide(NIPAm)and L-amino acid mo...Synthetic polymer hydrogel nanoparticles(NPs)were developed to function as abiotic affinity reagents for fibrinogen.These NPs were made using both temperature-sensitive N-isopropyl acrylamide(NIPAm)and L-amino acid monomers.Five kinds of L-amino acids were acryloylated to obtain functional monomers:L-phenylalanine(Phe)and L-leucine(Leu)with hydrophobic side chains,L-glutamic acid(Glu)with negative charges,and L-lysine(Lys)and L-arginine(Arg)with positive charges.After incubating the NPs with fibrinogen,g-globulin,and human serum albumin(HSA)respectively,the NPs that incorporated Nacryloyl-Arg monomers(AArg@NPs)showed the strongest and most specific binding affinity to fibrinogen,when compared with g-globulin and HSA.Additionally,the fibrinogen-AArg binding model had the best docking scores,and this may be due to the interaction of positively charged AArg@NPs and the negatively charged fibrinogen D domain and the hydrophobic interaction between them.The specific adsorption of AArg@NPs to fibrinogen was also confirmed by the immunoprecipitation assay,as the AArg@NPs selectively trapped the fibrinogen from a human plasma protein mixture.AArg@NPs had a strong selectivity for,and specificity to,fibrinogen and may be developed as a potential human fibrinogen-specific affinity reagent.展开更多
The present article deals with the natural nitrogen-15 abundance of ammonium nitrogen and fixed ammonium in different soils. Variations in the natural 15N abundance of ammonium nitrogen mineralized in soils under anae...The present article deals with the natural nitrogen-15 abundance of ammonium nitrogen and fixed ammonium in different soils. Variations in the natural 15N abundance of ammonium nitrogen mineralized in soils under anaerobic incubation condition were related to soil pH. The δ 15N of mineralizable N in acid soils was lower but that in neutral and calcareous soils was higher compared with the δ 15N of total N in the soils. A variation tendency was also found in the δ 15N of amino-acid N in the hydrolysates of soils. The natural 15N abundance of fixed ammonium was higher than that of total N in most surface soils and other soil horizons, indicating that the increase of δ 15N in the soil horizons beneath subsurface horizon of some forest soils and acid paddy soils was related to the higher δ 15N value of fixed ammonium in the soil.展开更多
In the rice-wheat rotation system,biochar(BC)can be applied at the initiation of the rice or wheat season.Here,we compared the effects of BC that were applied at two different crop seasons on wheat production,quality,...In the rice-wheat rotation system,biochar(BC)can be applied at the initiation of the rice or wheat season.Here,we compared the effects of BC that were applied at two different crop seasons on wheat production,quality,and soil profile properties in a rice-wheat rotation system with nitrogen(N)fertilizer applied at 280 kg/ha rate.Results showed that both wheat grain production and N recovery use efficiency were influenced by BC applied at two crop seasons.Biochar application did not affect the total non-essential amino-acid,but when applied during wheat season,BC significantly(p<0.05)increased total essential amino acid in grain by 12.3%,particularly for the valine(+48.2%),methionine(+43.8%),and isoleucine(+10.3%).We found that BC significantly(p<0.05)decreased the pH of soil at 0–6 cm and 20–30 cm by 0.14–0.18 and 0.05–0.08 units,respectively.The NH4+-N content of the whole observed soil profile were reduced by BC application,however,the effect of BC on NO3–-N content varied with the application season and profile depth.Interestingly,BC applied at wheat and rice season significantly(p<0.05)improved topsoil N contents by 48.4%and 19.7%,respectively.In addition,data suggested that BC applied during wheat season performed better in enhancing soil available phosphorus,potassium,and organic matter contents.In conclusion,we suggest that the optimum application time of BC for enhancing crop production and quality(take amino-acid content for example)and improving soil fertility is at the initiation of the wheat season.展开更多
The evolution of protein family is a process along the time course, thus any mathematical methods that can describe a process over time could be possible to describe an evolutionary process. In our previously concept-...The evolution of protein family is a process along the time course, thus any mathematical methods that can describe a process over time could be possible to describe an evolutionary process. In our previously concept-initiated study, we attempted to use the differential equation to describe the evolution of hemagglutinins from influenza A viruses, and to discuss various issues related to the building of differential equation. In this study, we attempted not only to use the differential equation to describe the evolution of matrix protein 2 family from influenza A virus, but also to use the analytical solution to fit its evolutionary process. The results showed that the fitting was possible and workable. The fitted model parameters provided a way to further determine the evolutionary dynamics and kinetics, a way to more precisely predict the time of occurrence of mutation, and a way to figure out the interaction between protein family and its environment.展开更多
Lysostaphin is widely used in clinical settings against Staphylococcus aureus, but its mutants can abolish its killing activity. The difficulty in studies of mutations in lysostaphin is the shortage of data, which may...Lysostaphin is widely used in clinical settings against Staphylococcus aureus, but its mutants can abolish its killing activity. The difficulty in studies of mutations in lysostaphin is the shortage of data, which may need many decades to collect, although lysostaphin is so important for clinical therapeutics and drug development. In order not to passively wait for the accumulation of new data, in this study 1) the 23,442 mutations in 1408 proteins from databank were used to determine whether the mutations in lysostaphin follow the general mutation trend obtained from the databank, 2) the amino-acid pair predictability was used to explore the underlined mechanism for lysostaphin mutations, and 3) the amino-acid distribution probability was used to associate the mutation with dysfunction of lysostaphin. The results show that the mutations in lysostaphin follow the general trend of mutations in proteins;the underlined mechanism for mutations in lysostaphin is explainable from a viewpoint of randomness, and a mutation with increased distribution probability would have a larger chance to dysfunction lysostaphin. This study provides useful information for future design of anti-S. aureus drug and enzyme engineering.展开更多
The detection of single amino-acid variants （SAVs） usually depends on single-nucleotide polymorphisms （SNPs） database. Here, we describe a novel method that discovers SAVs at proteome level independent of SNPs dat...The detection of single amino-acid variants （SAVs） usually depends on single-nucleotide polymorphisms （SNPs） database. Here, we describe a novel method that discovers SAVs at proteome level independent of SNPs data. Using mass spectrometry-based de novo sequencing algorithm, peptide-candidates are identified and compared with theoretical protein database to generate SAVs under pairing strategy, which is followed by database re-searching to control false discovery rate. in human brain tissues, we can confidently identify known and novel protein variants with diverse origins. Combined with DNA/RNA sequencing, we verify SAVs derived from DNA mutations, RNA alternative splicing, and unknown post-transcriptional mechanisms. Furthermore, quantitative analysis in human brain tissues reveals several tissue-specific differential expressions of SAVs. This approach provides a novel access to high-throughput detection of protein variants, which may offer the potential for clinical biomarker discovery and mechanistic research.展开更多
Single molecule protein sequencing would tremendously impact in proteomics and human biology and it would promote the development of novel diagnostic and therapeutic approaches.However,its technological realization ca...Single molecule protein sequencing would tremendously impact in proteomics and human biology and it would promote the development of novel diagnostic and therapeutic approaches.However,its technological realization can only be envisioned,and huge challenges need to be overcome.Major difficulties are inherent to the structure of proteins,which are composed by several different amino-acids.Despite long standing efforts,only few complex techniques,such as Edman degradation,liquid chromatography and mass spectroscopy,make protein sequencing possible.Unfortunately,these techniques present significant limitations in terms of amount of sample required and dynamic range of measurement.It is known that proteins can distinguish closely similar molecules.Moreover,several proteins can work as biological nanopores in order to perform single molecule detection and sequencing.Unfortunately,while DNA sequencing by means of nanopores is demonstrated,very few examples of nanopores able to perform reliable protein-sequencing have been reported sofar.Here,we investigate,by means of molecular dynamics simulations,how a re-engineered protein,acting as biological nanopore,can be used to recognize the sequence of a translocating peptide by sensing the MshapeH of individual amino-acids.In our simulations we demonstrate that it is possible to discriminate with high fidelity,9 different amino-acids in a short peptide translocating through the engineered construct.The method,here shown for fluorescence-based sequencing,does not require any labelling of the peptidic analyte.These results can pave the way for a new and highly sensitive method of sequencing.展开更多
Objective: To design and synthesize a series of chrysin derivatives and evaluate the antitumor activities with MTT assay, so as to investigate molecular structure-activity relationship with molecular docking.Methods: ...Objective: To design and synthesize a series of chrysin derivatives and evaluate the antitumor activities with MTT assay, so as to investigate molecular structure-activity relationship with molecular docking.Methods: Target products were synthesized with high yield by substitution reaction, hydrolysis reaction,esterification reaction, and saponification reaction in sequence, and activities of all compounds were evaluated with human gastric carcinoma cell lines MGC-803 and human breast carcinoma cell lines MCF-7 through standard MTT assay. Molecular docking results were calculated with Surflex Geom X programme of Sybyl X-2.0 version workstation.Results: 7-O-amino acids chrysin derivatives 6 a–6 l were synthesized and their inhibitory effects were evaluated by comparing the material chrysin with positive control drug 5-fluorouracil(5-FU). Among these derivatives, compound 5 b(IC50= 24.50 ± 2.26 μmol/L), 5 k(IC50= 24.30 ± 2.19 μmol/L), and 6 f(IC50= 24.61 ± 2.01 μmol/L) showed better inhibitory activities against MGC-803 cell lines, and compound 5 g(IC50= 13.15 ± 1.73 μmol/L) and 5 j(IC50= 12.34 ± 1.25 μmol/L) showed better inhibitory activities against MCF-7 cell lines than chrysin and 5-FU. Molecular docking scores showed a credible consistency compared with MTT results.Conclusion: Compounds 5 b, 5 d, 5 g, 5 j, 5 k, and 6 f showed good antiproliferative effects on specific tumor cells, and compound 5 g should be researched further when according to molecular docking.展开更多
Pigs are vital genetic mixing vessels for human and avian influenza viruses because their tracheal epitheliums possess both sialic acidα-2,6-Gal andα-2,3-Gal receptors.Cross-species transmission of influenza A virus...Pigs are vital genetic mixing vessels for human and avian influenza viruses because their tracheal epitheliums possess both sialic acidα-2,6-Gal andα-2,3-Gal receptors.Cross-species transmission of influenza A viruses from swine to humans occurs occasionally.The first case of human infection with the Eurasian avian-like H1N1 swine influenza virus(EAH1N1 SIVs)genotype G4 was detected in Jiangsu Province,China,in February 2023,and backtracking epidemiological investigations did not reveal a clear source of the infection.The hemagglutination(HA)and neuraminidase(NA)amino acid variant sites,antiviral drug susceptibility,and antigenic variation of the isolated A/Jiangsu/27271/2023(JS/27271/23)virus were analyzed,and we evaluated the protective effect of sera collected from occupationally exposed populations in 2024 against the virus.Compared with the vaccine strain,the nucleotide sequence similarities of JS/27271/23 HA and NA were 96.5%and 95.2%,respectively.JS/27271/23 was sensitive to polymerase inhibitors(favipiravir and baloxavir),and the antigenicity of its HA protein was 8-fold different from that of the vaccine strain.The percentage of occupationally exposed population with antibody titers of≥40 against A/Hunan/42443/2015(HN/42443/15)and A/Jiangsu/1/2011(JS/1/11)were 7.25%and 2.25%,respectively,and the geometric mean titers(GMT)were 6.24 and 5.34,respectively.Out of 400 serum samples examined,none had antibody titers of≥40 against JS/27271/23.This suggests that low serum levels of antibodies to EAH1N1 SIVs in occupationally exposed populations may not provide adequate protection because of significant differences in amino acid sites and antigenicity between this virus and the current vaccine strain of EAH1N1 SIVs.There is no evidence of human-to-human transmission of EAH1N1 SIVs.Therefore,surveillance for EAH1N1 SIVs and the development of new vaccine strains are required.展开更多
基金Supported by Henan Major Scientific and Technological Project(121100110300)Outstanding Youth Project of Henan Academy of Agricultural Sciences(2013YQ006)~~
文摘In this study, nine high-lysine maize kernels and two kernels of common maize hybrid were used as experiment materials, and quantitative determination of lysine contents in high-lysine maize kernels and common maize kernels was carried out using Hitachi L-8900 Automatic Amino-acid Analyzer, to know the effect of the Analyzer in distinguishing the lysine contents between common maize kernels and high-lysine maize kernels. The results showed that the lysine contents of high-lysine maize kernels were among 0.34%-0.42%, while of common maize kernels were a- mong 0.24%-0.25%, and the difference was significant. Compared with other tradi- tional methods, this method is rapid, simple, sensitive, highly reproductive and needs fewer maize kernels, thus it is applicable in maize breeding.
文摘The polymerase acidic protein is an important family of proteins from influenza A virus, which is classified as many different subtypes or spe-cies. Thus, an important question is if these classifications are numerically distinguishable with respect to the polymerase acidic protein. The amino-acid pair predictability was used to transfer 2432 polymerase acidic proteins into 2432 scalar data. The one-way ANOVA found these polymerase acidic proteins distinguish-able in terms of subtypes and species. However, the large residuals in ANOVA suggested a pos-sible large intra-subtype/species variation. Therefore, the inter- and intra-subtype/species variations were studied using the model II ANOVA. The results showed that the in-tra-subtype/species variations accounted most of variation, which was 100% in total for both inter- and intra- subtype/species variations. Our analysis threw lights on the issue of how to de-termine a wide variety of patterns of antigenic variation across space and time, and within and between subtypes as well as hosts.
文摘The mutation pattern in protein is a very important feature and is studied through various approaches including the study on mutation pattern in domains where amino acids are converted into numbers from letters. In this study, we converted the amino acids in human adrenoleukodystrophy protein with its 128 missense mutations into random domain using the amino-acid pair predictability, and then we studied their mutation patterns. The results show 1) the mutations are more likely to target the amino-acid pairs whose actual frequency is larger than their predicted one, 2) the mutations are more likely to form the amino-acid pairs whose actual frequency is smaller than their predicted frequency, 3) mutations are more likely to occur at unpredictable amino-acid pairs, and 4) mutations have the trend to narrow the difference between predicted and actual frequencies of amino-acid pairs.
文摘A formalin-treated polyvinyl-alcohol (PVF) sponge is convenient as a scaffold because its configuration is easily modified. However, coating the sponge with an adhesive chemical agent is necessary to attach bone marrow cells (BMCs) to the sponge structure. Moreover, it was considered that a hybrid scaffold composed of a sponge and enveloped cylindrical porous hydroxyapatite (HA) would be convenient. In this study, the effect of leucine (Leu) coating on a PVF sponge was examined for osteogenesis on an HA/PVF hybrid scaffold by rat BMCs (rBMCs). In an in vivo assessment, the sponge immersed in Leu solution (10 mg/ml) was inserted into the hollow center of cylindrical HA. The sponge received 1.5 × 106 rBMCs obtained from male Fischer 344 rats. The hybrid scaffolds were then implanted subcutaneously of syngeneic rats for 6 weeks. In vitro assessment of Leu to hard tissue formation with coating on the well or addition in rBMC culture medium was also performed in a 6-well plate for 2 weeks. In vivo examinations showed the excellent effect of Leu coating on PVF sponge. Leu-coated PVF sponge in the scaffolds showed marked new bone formation in the pores by histological examination. Leu-coated PVF sponge showed a high quantity of osteocalcine (OC). HA might prevent the release of rBMCs from PVF as a barrier. In in vitro examinations, the quantity of OC in rBMC culture with and without the addition of Leu in culture medium showed no significant difference. However, addition of Leu showed significant ALP activity level in culture medium. Leu coating in culture plate wells showed no influence on the quantity of OC. It was concluded from the results that Leu might prevent the emigration of rBMCs to the outside of the scaffold and promote the differentiation of cells to osteoblasts in the scaffold.
文摘Geometry optimization at the B3LYP/6-31＋＋G＊ level of theory has been undertaken on clusters containing L-Met （L-methionine） or L-Cys （L-cysteine） surrounded by eight water molecules. The comparison of the structural parameters of L-Met and L-Cys with X-ray experimental values is in good agreement within 4.8%. This result shows that the privileged positions of water molecules and the possible hydrogen bonding network formed around the backbone of both AAs （amino acids） are adequate. Subsequent calculations of the harmonic vibrational modes followed by a post-processing treatment enable us to assign the vibrational modes of L-Met and L-Cys surrounded explicitly by eight water molecules. The frequencies of the assigned modes are in good agreement with available IR （infra red） and Raman values within 5%.
文摘The two waves period of the COVID-19 pandemic saw the use of hydro- alcoholic gel and the consumption of capsules containing improved traditional remedies. At one point, there was a stock-out and a price increase forthese products. Furthermore, in the food industry, the catering industry adopts gelatin in its current practice. Pig gelatin dominates the international market. And for some religious practices, pork is forbidden and yet these people consume them without taking notice. The production of gelatin from broiler feet seems economically viable because broiler feet are considered slaughterhouse waste that is sold at very low prices. The poultry industry has seen an increase in broiler farming over the last twenty years. However, the latter has all the characteristics required for the production of gelatin. It will therefore comply with the standards of use described in the international codex oenological for gelatins. Physical and chemical analyses such as, ash content, moisture content, and pH measurements were done for the extracted gelatins. Sensible elements are checked with ED XRF spectroscopy. All the results were good and showed without any doubt that broiler gelatin is edible.
文摘Surfactant flooding is an important technique used to improve oil recovery from mature oil reservoirs due to minimizing the interfacial tension(IFT)between oil and water and/or altering the rock wettability toward water-wet using various surfactant agents including cationic,anionic,non-ionic,and amphoteric varieties.In this study,two amino-acid based surfactants,named lauroyl arginine(L-Arg)and lauroyl cysteine(L-Cys),were synthesized and used to reduce the IFT of oil–water systems and alter the wettability of carbonate rocks,thus improving oil recovery from oil-wet carbonate reservoirs.The synthesized surfactants were characterized using Fourier transform infrared spectroscopy and nuclear magnetic resonance analyses,and the critical micelle concentration(CMC)of surfactant solutions was determined using conductivity,pH,and turbidity techniques.Experimental results showed that the CMCs of L-Arg and L-Cys solutions were 2000 and 4500 ppm,respectively.It was found that using L-Arg and L-Cys solutions at their CMCs,the IFT and contact angle were reduced from 34.5 to 18.0 and15.4 mN/m,and from 144°to 78°and 75°,respectively.Thus,the L-Arg and L-Cys solutions enabled approximately 11.9%and 8.9%additional recovery of OOIP(original oil in place).It was identified that both amino-acid surfactants can be used to improve oil recovery due to their desirable effects on the EOR mechanisms at their CMC ranges.
基金Supported by OTKA-K105530,-K81117 and ETT-028-02the János Bolyai Research Grant,to Veres Gthe János Bolyai Research Scholarship of the Hungarian Academy of Sciences
文摘AIM: To investigate the characteristics of mucosal le-sions and their relation to laboratory data and long-term follow up in breast-fed infants with allergic colitis. METHODS: In this study 31 breast-fed infants were prospectively evaluated (mean age, 17.4 wk) whose rectal bleeding had not ceased after a maternal elimi-nation diet for cow's milk. Thirty-four age-matched and breast-fed infants (mean age, 16.9 wk) with no rectal bleeding were enrolled for laboratory testing as con-trols. Laboratory findings, colonoscopic and histological characteristics were prospectively evaluated in infants with rectal bleeding. Long-term follow-up with differ-ent nutritional regimes (L-amino-acid based formula or breastfeeding) was also included. RESULTS: Iron deficiency, peripheral eosinophilia andthrombocytosis were significantly higher in patients with allergic colitis in comparison to controls (8.4±3.2 μmol/L vs 13.7±4.7 μmol/L, P<0.001; 0.67±0.49 G/L vs 0.33±0.17 G/L, P<0.001; 474±123 G/L vs 376±89 G/L, P<0.001, respectively). At colonosco-py, lymphonodular hyperplasia or aphthous ulceration were present in 83% of patients. Twenty-two patients were given L-amino acid-based formula and 8 contin-ued the previous feeding. Time to cessation of rectal bleeding was shorter in the special formula feeding group (mean, 1.4 wk; range, 0.5-3 wk) when com-pared with the breast-feeding group (mean, 5.3 wk; range, 2-9 wk). Nevertheless, none of the patients ex-hibited rectal bleeding at the 3-mo visit irrespective of the type of feeding. Peripheral eosinophilia and cessa-tion of rectal bleeding after administration of elemental formula correlated with a higher density of mucosal eosinophils. CONCLUSION: Infant hematochezia, after cow's milk allergy exclusion, is generally a benign and probably self-limiting disorder despite marked mucosal abnor-mality. Formula feeding results in shorter time to cessa-tion of rectal bleeding; however, breast-feeding should not be discouraged in long-lasting hematochezia.
基金This work was supported by the Natural Science Foundation of Guangdong Province,China(Grant No.:2017A030313775)the Science and Technology Planning Project of Guangdong Province,China(Grant No.:2016A010103016)the Science and Technology Planning Project of Guangzhou City of Guangdong Province,China(Grant No.:201607010148).
文摘Synthetic polymer hydrogel nanoparticles(NPs)were developed to function as abiotic affinity reagents for fibrinogen.These NPs were made using both temperature-sensitive N-isopropyl acrylamide(NIPAm)and L-amino acid monomers.Five kinds of L-amino acids were acryloylated to obtain functional monomers:L-phenylalanine(Phe)and L-leucine(Leu)with hydrophobic side chains,L-glutamic acid(Glu)with negative charges,and L-lysine(Lys)and L-arginine(Arg)with positive charges.After incubating the NPs with fibrinogen,g-globulin,and human serum albumin(HSA)respectively,the NPs that incorporated Nacryloyl-Arg monomers(AArg@NPs)showed the strongest and most specific binding affinity to fibrinogen,when compared with g-globulin and HSA.Additionally,the fibrinogen-AArg binding model had the best docking scores,and this may be due to the interaction of positively charged AArg@NPs and the negatively charged fibrinogen D domain and the hydrophobic interaction between them.The specific adsorption of AArg@NPs to fibrinogen was also confirmed by the immunoprecipitation assay,as the AArg@NPs selectively trapped the fibrinogen from a human plasma protein mixture.AArg@NPs had a strong selectivity for,and specificity to,fibrinogen and may be developed as a potential human fibrinogen-specific affinity reagent.
基金Project supported by the National Natural Science Foundation of China.
文摘The present article deals with the natural nitrogen-15 abundance of ammonium nitrogen and fixed ammonium in different soils. Variations in the natural 15N abundance of ammonium nitrogen mineralized in soils under anaerobic incubation condition were related to soil pH. The δ 15N of mineralizable N in acid soils was lower but that in neutral and calcareous soils was higher compared with the δ 15N of total N in the soils. A variation tendency was also found in the δ 15N of amino-acid N in the hydrolysates of soils. The natural 15N abundance of fixed ammonium was higher than that of total N in most surface soils and other soil horizons, indicating that the increase of δ 15N in the soil horizons beneath subsurface horizon of some forest soils and acid paddy soils was related to the higher δ 15N value of fixed ammonium in the soil.
基金financially supported by the Higher Education Department of Guangdong Province (No.2020KCXTD025)the National Key Research and Development Program of China (No.2017YFD0800404).
文摘In the rice-wheat rotation system,biochar(BC)can be applied at the initiation of the rice or wheat season.Here,we compared the effects of BC that were applied at two different crop seasons on wheat production,quality,and soil profile properties in a rice-wheat rotation system with nitrogen(N)fertilizer applied at 280 kg/ha rate.Results showed that both wheat grain production and N recovery use efficiency were influenced by BC applied at two crop seasons.Biochar application did not affect the total non-essential amino-acid,but when applied during wheat season,BC significantly(p<0.05)increased total essential amino acid in grain by 12.3%,particularly for the valine(+48.2%),methionine(+43.8%),and isoleucine(+10.3%).We found that BC significantly(p<0.05)decreased the pH of soil at 0–6 cm and 20–30 cm by 0.14–0.18 and 0.05–0.08 units,respectively.The NH4+-N content of the whole observed soil profile were reduced by BC application,however,the effect of BC on NO3–-N content varied with the application season and profile depth.Interestingly,BC applied at wheat and rice season significantly(p<0.05)improved topsoil N contents by 48.4%and 19.7%,respectively.In addition,data suggested that BC applied during wheat season performed better in enhancing soil available phosphorus,potassium,and organic matter contents.In conclusion,we suggest that the optimum application time of BC for enhancing crop production and quality(take amino-acid content for example)and improving soil fertility is at the initiation of the wheat season.
文摘The evolution of protein family is a process along the time course, thus any mathematical methods that can describe a process over time could be possible to describe an evolutionary process. In our previously concept-initiated study, we attempted to use the differential equation to describe the evolution of hemagglutinins from influenza A viruses, and to discuss various issues related to the building of differential equation. In this study, we attempted not only to use the differential equation to describe the evolution of matrix protein 2 family from influenza A virus, but also to use the analytical solution to fit its evolutionary process. The results showed that the fitting was possible and workable. The fitted model parameters provided a way to further determine the evolutionary dynamics and kinetics, a way to more precisely predict the time of occurrence of mutation, and a way to figure out the interaction between protein family and its environment.
文摘Lysostaphin is widely used in clinical settings against Staphylococcus aureus, but its mutants can abolish its killing activity. The difficulty in studies of mutations in lysostaphin is the shortage of data, which may need many decades to collect, although lysostaphin is so important for clinical therapeutics and drug development. In order not to passively wait for the accumulation of new data, in this study 1) the 23,442 mutations in 1408 proteins from databank were used to determine whether the mutations in lysostaphin follow the general mutation trend obtained from the databank, 2) the amino-acid pair predictability was used to explore the underlined mechanism for lysostaphin mutations, and 3) the amino-acid distribution probability was used to associate the mutation with dysfunction of lysostaphin. The results show that the mutations in lysostaphin follow the general trend of mutations in proteins;the underlined mechanism for mutations in lysostaphin is explainable from a viewpoint of randomness, and a mutation with increased distribution probability would have a larger chance to dysfunction lysostaphin. This study provides useful information for future design of anti-S. aureus drug and enzyme engineering.
文摘The detection of single amino-acid variants （SAVs） usually depends on single-nucleotide polymorphisms （SNPs） database. Here, we describe a novel method that discovers SAVs at proteome level independent of SNPs data. Using mass spectrometry-based de novo sequencing algorithm, peptide-candidates are identified and compared with theoretical protein database to generate SAVs under pairing strategy, which is followed by database re-searching to control false discovery rate. in human brain tissues, we can confidently identify known and novel protein variants with diverse origins. Combined with DNA/RNA sequencing, we verify SAVs derived from DNA mutations, RNA alternative splicing, and unknown post-transcriptional mechanisms. Furthermore, quantitative analysis in human brain tissues reveals several tissue-specific differential expressions of SAVs. This approach provides a novel access to high-throughput detection of protein variants, which may offer the potential for clinical biomarker discovery and mechanistic research.
基金the Horizon 2020 Program,FET-Open:PROSEQO,Grant Agreement no.[687089].We acknowledge PRACE for awarding us access to Marconi at CINECA,Italy.
文摘Single molecule protein sequencing would tremendously impact in proteomics and human biology and it would promote the development of novel diagnostic and therapeutic approaches.However,its technological realization can only be envisioned,and huge challenges need to be overcome.Major difficulties are inherent to the structure of proteins,which are composed by several different amino-acids.Despite long standing efforts,only few complex techniques,such as Edman degradation,liquid chromatography and mass spectroscopy,make protein sequencing possible.Unfortunately,these techniques present significant limitations in terms of amount of sample required and dynamic range of measurement.It is known that proteins can distinguish closely similar molecules.Moreover,several proteins can work as biological nanopores in order to perform single molecule detection and sequencing.Unfortunately,while DNA sequencing by means of nanopores is demonstrated,very few examples of nanopores able to perform reliable protein-sequencing have been reported sofar.Here,we investigate,by means of molecular dynamics simulations,how a re-engineered protein,acting as biological nanopore,can be used to recognize the sequence of a translocating peptide by sensing the MshapeH of individual amino-acids.In our simulations we demonstrate that it is possible to discriminate with high fidelity,9 different amino-acids in a short peptide translocating through the engineered construct.The method,here shown for fluorescence-based sequencing,does not require any labelling of the peptidic analyte.These results can pave the way for a new and highly sensitive method of sequencing.
基金supported by Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study(No.2014-405)Hunan Provincial Department of Education Project(14C1003)
文摘Objective: To design and synthesize a series of chrysin derivatives and evaluate the antitumor activities with MTT assay, so as to investigate molecular structure-activity relationship with molecular docking.Methods: Target products were synthesized with high yield by substitution reaction, hydrolysis reaction,esterification reaction, and saponification reaction in sequence, and activities of all compounds were evaluated with human gastric carcinoma cell lines MGC-803 and human breast carcinoma cell lines MCF-7 through standard MTT assay. Molecular docking results were calculated with Surflex Geom X programme of Sybyl X-2.0 version workstation.Results: 7-O-amino acids chrysin derivatives 6 a–6 l were synthesized and their inhibitory effects were evaluated by comparing the material chrysin with positive control drug 5-fluorouracil(5-FU). Among these derivatives, compound 5 b(IC50= 24.50 ± 2.26 μmol/L), 5 k(IC50= 24.30 ± 2.19 μmol/L), and 6 f(IC50= 24.61 ± 2.01 μmol/L) showed better inhibitory activities against MGC-803 cell lines, and compound 5 g(IC50= 13.15 ± 1.73 μmol/L) and 5 j(IC50= 12.34 ± 1.25 μmol/L) showed better inhibitory activities against MCF-7 cell lines than chrysin and 5-FU. Molecular docking scores showed a credible consistency compared with MTT results.Conclusion: Compounds 5 b, 5 d, 5 g, 5 j, 5 k, and 6 f showed good antiproliferative effects on specific tumor cells, and compound 5 g should be researched further when according to molecular docking.
基金supported by the National Key Research and Development Program of China(Grant number 2023YFC2606500)Huai'an City Innovation Service Capacity Building Program(Key Laboratory Construction)(Grant number HAP201906)Jiangsu Province 333 Project.
文摘Pigs are vital genetic mixing vessels for human and avian influenza viruses because their tracheal epitheliums possess both sialic acidα-2,6-Gal andα-2,3-Gal receptors.Cross-species transmission of influenza A viruses from swine to humans occurs occasionally.The first case of human infection with the Eurasian avian-like H1N1 swine influenza virus(EAH1N1 SIVs)genotype G4 was detected in Jiangsu Province,China,in February 2023,and backtracking epidemiological investigations did not reveal a clear source of the infection.The hemagglutination(HA)and neuraminidase(NA)amino acid variant sites,antiviral drug susceptibility,and antigenic variation of the isolated A/Jiangsu/27271/2023(JS/27271/23)virus were analyzed,and we evaluated the protective effect of sera collected from occupationally exposed populations in 2024 against the virus.Compared with the vaccine strain,the nucleotide sequence similarities of JS/27271/23 HA and NA were 96.5%and 95.2%,respectively.JS/27271/23 was sensitive to polymerase inhibitors(favipiravir and baloxavir),and the antigenicity of its HA protein was 8-fold different from that of the vaccine strain.The percentage of occupationally exposed population with antibody titers of≥40 against A/Hunan/42443/2015(HN/42443/15)and A/Jiangsu/1/2011(JS/1/11)were 7.25%and 2.25%,respectively,and the geometric mean titers(GMT)were 6.24 and 5.34,respectively.Out of 400 serum samples examined,none had antibody titers of≥40 against JS/27271/23.This suggests that low serum levels of antibodies to EAH1N1 SIVs in occupationally exposed populations may not provide adequate protection because of significant differences in amino acid sites and antigenicity between this virus and the current vaccine strain of EAH1N1 SIVs.There is no evidence of human-to-human transmission of EAH1N1 SIVs.Therefore,surveillance for EAH1N1 SIVs and the development of new vaccine strains are required.
