The lipid metabolism plays an essential role in the development andreproduction of insects, and lipases are important enzymes in lipid metabolism. In Nilaparvatalugens, an important insect pest on rice, triacylglycero...The lipid metabolism plays an essential role in the development andreproduction of insects, and lipases are important enzymes in lipid metabolism. In Nilaparvatalugens, an important insect pest on rice, triacylglycerol hydrolytic activities weredifferent among tissues, with high activity in integument, ovary, and fat body, but low activityin intestine. To figure out the tissue-specific triacylglycerol hydrolytic activity, weidentified 43 lipases in N. lugens. Of these 43 lipases, 23 belonged to neutral lipases, sothis group was selected to perform further experiments on triacylglycerol hydrolysis. Thecomplete motifs of catalytic triads, β9 loop, and lid motif, are required for the triacylglycerolhydrolytic activity in neutral lipases, which were found in some neutral lipases withhigh gene expression levels in integument and ovary, but not in intestine. The recombinantproteins of 3 neutral lipases with or without 3 complete motifs were obtained, and the activitydetermination confirmed the importance of 3 motifs. Silencing XM_022331066.1,which is highly expressed in ovary and with 3 complete motifs, significantly decreasedthe egg production and hatchability of N. lugens, partially through decline of the lipidmetabolism. In summary, at least one-third of important motifs were incomplete in allneutral lipases with high gene expression in intestine, which could partially explain whythe lipase activity in intestine was much lower than that in other tissues. The low activityto hydrolyze triacylglycerol in N. lugens intestine might be associated with its food resourceand nutrient components, and the ovary-specific neutral lipases were important forN. lugens reproduction.展开更多
Mimetic enzymes are devised as alternates or supplements of natural enzymes in broad fields but regulating their activities in a switchable manner remains challenging.Herein,we proposed an enzymatic self-assembly/disa...Mimetic enzymes are devised as alternates or supplements of natural enzymes in broad fields but regulating their activities in a switchable manner remains challenging.Herein,we proposed an enzymatic self-assembly/disassembly strategy to address this issue.A peptide molecule Nap FFEYIH(YH) was rationally designed which,after self-assembling into nanofibers,lined up the histidine moieties to form active hydrolysis centers for mimicking hydrolase activity.Enzymatic dephosphorylation of Nap FFEYp IH(Yp H) by alkaline phosphatase to yield YH also turned “ON” the hydrolase activity.In turn,phosphorylation of YH by phosphokinase epidermal growth factor receptor to yield Yp H disassembled the nanofibers and thus turned the activity “OFF”.As such,the “ON”/“OFF” of the mimetic hydrolase activities could be regulated under physiological conditions through ALP/EGFR-mediated self-assembly/disassembly of histidine nanofibers.This work provides a feasible strategy for the on-demand fabrication of artificial enzymes with controllable and superior activities.展开更多
A new metallomicelle, formed by Cu2+ Or Zn2+ ion and N-tetradecyl-2-(N-2-hydroxyethyl aminomethyl) imidazol in the presence of cetyltrimethylammonium bromide, was found to possess remarkable catalytic activity to the ...A new metallomicelle, formed by Cu2+ Or Zn2+ ion and N-tetradecyl-2-(N-2-hydroxyethyl aminomethyl) imidazol in the presence of cetyltrimethylammonium bromide, was found to possess remarkable catalytic activity to the hydrolysis of p-nitrophenyl picolinate.展开更多
Microorganisms are omnipresent in all environments and play mainly the role of transformers, thanks to the multiple enzymes they are able to produce. In order to valorize fermented foods in the Republic of the Congo, ...Microorganisms are omnipresent in all environments and play mainly the role of transformers, thanks to the multiple enzymes they are able to produce. In order to valorize fermented foods in the Republic of the Congo, this work aimed to characterize and study some properties of microorganisms isolated from samples of peppers sold in three markets of Brazzaville. A numeration of the total aerobic mesophilic flora (TAMF) was made in a solid medium, allowing the evaluation of each sample’s microbial concentration. The microbial mass varied from 2.8 × 105 CFU/g for the Ouénzé sample to 1.8 × 104 CFU/g for the Total sample and 2 × 104 CFU/g for the Moungali market sample. The evaluation of the enzymatic properties of the Bacillus isolates showed that 68.42% were capable of producing cellulases and 78.94% were capable of producing amylases and proteases. Antimicrobial activities revealed that 63.15% of the isolates were able to secrete inhibitory substances against E. coli and Staphylococcus aureus. Molecular analysis by PCR amplification, sequencing of the 16S rRNA gene and BLAST bioinformatics analysis provides newly identified bacteria strains with new accession numbers in GenBank: Bacillus thuringiensis MBCBR322 (OP474008), Bacillus megaterium MBCBJ1822 (OP476493), Bacillus thuringiensis MBCBR222 (OP476494), Priestia megaterium MBCBJ2022 (OP476495) and Lactobacillus paraplantarum MBCBR1522 (OP476496). Multiple sequences alignment of identified sequences with their homologs of GenBank has shown high similarities. The phylogenetic inference assay has provided the two groups of strains observed in this study, and the two groups are very coherent with the phylogeny of the reference.展开更多
The effects of La on some hydrolytic enzyme activities in red soil were studied in incubation and pot culture experiments. In the incubation experiment, La slightly stimulates the activities of urease and acidic phosp...The effects of La on some hydrolytic enzyme activities in red soil were studied in incubation and pot culture experiments. In the incubation experiment, La slightly stimulates the activities of urease and acidic phosphatase in soil and strongly stimulates sucrase activity in soil. In the pot culture experiment, La stimulates the activities of urease, acidic phosphatase and sucrase to different degrees. The stimulative effects of rare earth elements (REE) on hydrolytic enzyme activities in soil may result in increasing yield of crops.展开更多
Chia seed mucilage was probed for the presence of structurally diverse free oligosaccharides along with the assessment of hydrolytic and transgalactosylation activities of α-galactosidase from a probiotic bacterium-L...Chia seed mucilage was probed for the presence of structurally diverse free oligosaccharides along with the assessment of hydrolytic and transgalactosylation activities of α-galactosidase from a probiotic bacterium-Lactiplantibacillus plantarum WCFS1(LpαG)on isolated oligosaccharides.Porous graphitic carbon-liquid chromatography-tandem mass spectrometry(PGC LC-MS/MS)analysis revealed the presence of mainly sucrose(disaccharide),planteose(trisaccharide),few isomeric tetrasaccharides as well as lower abundance of isomeric tri-,tetra-,penta-and hexasaccharides.In vitro evaluation of the digestibility of planteose and tetrasaccharides to the intestinal enzymes did not generate monosaccharides.However,LpαG displayed hydrolytic activity towards planteose and selectively acted on two tetrasaccharides,which were identified as sesamose and stachyose.In addition,transglycosylation property of LpαG using planteose led to the synthesis of sesamose.Thus,the hydrolysis of planteose and sesamose was demonstrated for the first time for anα-galactosidase from the probiotic bacterium.Furthermore,the oligosaccharides pool was shown to influence the growth of probiotic L.acidophilus,L.brevis and L.plantarum in vitro,along with the production of short chain fatty acids(SCFAs).These findings would contribute to the potential application of chia seeds to further enhance its health benefits.展开更多
Lactosucrose is a widely known prebiotic oligosaccharide,but it is synthesized generally with a low efficiency by using the available enzymes.To search for levansucrase(LS)for effective synthesis of lactosucrose has b...Lactosucrose is a widely known prebiotic oligosaccharide,but it is synthesized generally with a low efficiency by using the available enzymes.To search for levansucrase(LS)for effective synthesis of lactosucrose has become a significant research challenge.In this study,LS was produced by Bacillus subtilis LG-4 isolated and identified from traditional natto,and it was separated and purified by ammonium sulfate fractionation and DEAE-Sepharose Fast Flow chromatography.It was further enzymatically characterized in terms of amino acid sequencing,optimum reaction conditions and kinetic parameters.The results showed that the LS(12.68 U/mL)was produced under the optimized fermentation conditions of 50 g/L sucrose,5 g/L soy peptone,10 g/L yeast extract,inoculation rate 2%,initial pH 6.5,at 37℃ for 20 h,and the kinetic models for LS production were also established.The LS was identified to be a GH 68 family protein(53 kDa),which was not reported earlier.It had an optimal pH of 6.5,and optimal temperatures of 40℃ and 45℃ for sucrose hydrolysis and transfructosylation activities,respectively.The enzyme showed good stability under the conditions of 35℃–45℃ and pH 6.0–7.0.The kinetic parameters were determined with Vmax of 54.65 mM/min and a relatively low Km value(18.69 mM),suggesting high affinity of the enzyme for substrate(sucrose).Lactosucrose(128.96 g/L)was effectively synthesized by using the LS at a higher productivity(368.88 g/L/h)than those reported in the literatures.Therefore,this study demonstrated a novel microbial LS with high prospects for industrial biosynthesis of lactosucrose.展开更多
In the present study,the hydrolysis and acyltransferase activities of bifunctional feruloyl esterases DLFae4 were enhanced by a combination of multiple mutation strategies based on rationally predicting the potential ...In the present study,the hydrolysis and acyltransferase activities of bifunctional feruloyl esterases DLFae4 were enhanced by a combination of multiple mutation strategies based on rationally predicting the potential beneficial mutation sites.Results showed that V149D&I172G was the strongest double mutant(589.67 U/mg),and the triple mutant N173G&N169G&I148G exhibited 3.60 and 5.57 times higher hydrolytic activity and catalytic efficiency towards MFA,respectively.Furthermore,the triple mutant releases 16.16 mg/g ferulic acid(FA)from de-starched wheat bran(DSWB)in synergy with xylanase,which was increased by 9.34 times than that released by DLFae4 alone,and was the highest reported release amount.The double mutant V251Y&A341G with weakened hydrolytic activity but exhibited 4.30 times higher acyltransferase activity than that of DLFae4,and the corresponding acyl transfer efficiency improved by 11.37 times,representing the highest acyltransferase activity to date.The results from the current investigation demonstrate that combining multiple rational design methods is a robust pipeline for improving enzyme activities and provides new insights for enzyme modification.展开更多
Prodrug design is an important part of drug discovery.Prodrugs can offer many advantages over parent drugs such as increased solubility,enhanced stability,improved bioavailability,reduced side effects,and better selec...Prodrug design is an important part of drug discovery.Prodrugs can offer many advantages over parent drugs such as increased solubility,enhanced stability,improved bioavailability,reduced side effects,and better selectivity.Many prodrugs have been used successfully in the clinic;examples include oseltamivir in anti-influenza therapy,enalapril in anti-hypertension therapy,capecitabine in cancer therapy,and omeprazole in the treatment of peptic ulcer.A key step in prodrug design is the incorporation of an activation mechanism that can convert the prodrug into the active species in an efficient and/or controlled manner to meet the needs of a given medical application.Prodrug activation can be achieved through enzyme-mediated hydrolytic or oxidoreductive processes while activation of some prodrugs may proceed through pure chemical nonenzymatic processes.This review focuses on the hydrolytic enzymes that have been used in prodrug activation,including transferases,hydrolases,and lyases.展开更多
基金the National Natural Science Foundation of China(grant number 31830075)the National Key Research and Development Program of China(2021YFD1401100).
文摘The lipid metabolism plays an essential role in the development andreproduction of insects, and lipases are important enzymes in lipid metabolism. In Nilaparvatalugens, an important insect pest on rice, triacylglycerol hydrolytic activities weredifferent among tissues, with high activity in integument, ovary, and fat body, but low activityin intestine. To figure out the tissue-specific triacylglycerol hydrolytic activity, weidentified 43 lipases in N. lugens. Of these 43 lipases, 23 belonged to neutral lipases, sothis group was selected to perform further experiments on triacylglycerol hydrolysis. Thecomplete motifs of catalytic triads, β9 loop, and lid motif, are required for the triacylglycerolhydrolytic activity in neutral lipases, which were found in some neutral lipases withhigh gene expression levels in integument and ovary, but not in intestine. The recombinantproteins of 3 neutral lipases with or without 3 complete motifs were obtained, and the activitydetermination confirmed the importance of 3 motifs. Silencing XM_022331066.1,which is highly expressed in ovary and with 3 complete motifs, significantly decreasedthe egg production and hatchability of N. lugens, partially through decline of the lipidmetabolism. In summary, at least one-third of important motifs were incomplete in allneutral lipases with high gene expression in intestine, which could partially explain whythe lipase activity in intestine was much lower than that in other tissues. The low activityto hydrolyze triacylglycerol in N. lugens intestine might be associated with its food resourceand nutrient components, and the ovary-specific neutral lipases were important forN. lugens reproduction.
基金supported by the National Natural Science Foundation of China (22234002,22204019,82172097)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22_0245)。
文摘Mimetic enzymes are devised as alternates or supplements of natural enzymes in broad fields but regulating their activities in a switchable manner remains challenging.Herein,we proposed an enzymatic self-assembly/disassembly strategy to address this issue.A peptide molecule Nap FFEYIH(YH) was rationally designed which,after self-assembling into nanofibers,lined up the histidine moieties to form active hydrolysis centers for mimicking hydrolase activity.Enzymatic dephosphorylation of Nap FFEYp IH(Yp H) by alkaline phosphatase to yield YH also turned “ON” the hydrolase activity.In turn,phosphorylation of YH by phosphokinase epidermal growth factor receptor to yield Yp H disassembled the nanofibers and thus turned the activity “OFF”.As such,the “ON”/“OFF” of the mimetic hydrolase activities could be regulated under physiological conditions through ALP/EGFR-mediated self-assembly/disassembly of histidine nanofibers.This work provides a feasible strategy for the on-demand fabrication of artificial enzymes with controllable and superior activities.
文摘A new metallomicelle, formed by Cu2+ Or Zn2+ ion and N-tetradecyl-2-(N-2-hydroxyethyl aminomethyl) imidazol in the presence of cetyltrimethylammonium bromide, was found to possess remarkable catalytic activity to the hydrolysis of p-nitrophenyl picolinate.
文摘Microorganisms are omnipresent in all environments and play mainly the role of transformers, thanks to the multiple enzymes they are able to produce. In order to valorize fermented foods in the Republic of the Congo, this work aimed to characterize and study some properties of microorganisms isolated from samples of peppers sold in three markets of Brazzaville. A numeration of the total aerobic mesophilic flora (TAMF) was made in a solid medium, allowing the evaluation of each sample’s microbial concentration. The microbial mass varied from 2.8 × 105 CFU/g for the Ouénzé sample to 1.8 × 104 CFU/g for the Total sample and 2 × 104 CFU/g for the Moungali market sample. The evaluation of the enzymatic properties of the Bacillus isolates showed that 68.42% were capable of producing cellulases and 78.94% were capable of producing amylases and proteases. Antimicrobial activities revealed that 63.15% of the isolates were able to secrete inhibitory substances against E. coli and Staphylococcus aureus. Molecular analysis by PCR amplification, sequencing of the 16S rRNA gene and BLAST bioinformatics analysis provides newly identified bacteria strains with new accession numbers in GenBank: Bacillus thuringiensis MBCBR322 (OP474008), Bacillus megaterium MBCBJ1822 (OP476493), Bacillus thuringiensis MBCBR222 (OP476494), Priestia megaterium MBCBJ2022 (OP476495) and Lactobacillus paraplantarum MBCBR1522 (OP476496). Multiple sequences alignment of identified sequences with their homologs of GenBank has shown high similarities. The phylogenetic inference assay has provided the two groups of strains observed in this study, and the two groups are very coherent with the phylogeny of the reference.
文摘The effects of La on some hydrolytic enzyme activities in red soil were studied in incubation and pot culture experiments. In the incubation experiment, La slightly stimulates the activities of urease and acidic phosphatase in soil and strongly stimulates sucrase activity in soil. In the pot culture experiment, La stimulates the activities of urease, acidic phosphatase and sucrase to different degrees. The stimulative effects of rare earth elements (REE) on hydrolytic enzyme activities in soil may result in increasing yield of crops.
文摘Chia seed mucilage was probed for the presence of structurally diverse free oligosaccharides along with the assessment of hydrolytic and transgalactosylation activities of α-galactosidase from a probiotic bacterium-Lactiplantibacillus plantarum WCFS1(LpαG)on isolated oligosaccharides.Porous graphitic carbon-liquid chromatography-tandem mass spectrometry(PGC LC-MS/MS)analysis revealed the presence of mainly sucrose(disaccharide),planteose(trisaccharide),few isomeric tetrasaccharides as well as lower abundance of isomeric tri-,tetra-,penta-and hexasaccharides.In vitro evaluation of the digestibility of planteose and tetrasaccharides to the intestinal enzymes did not generate monosaccharides.However,LpαG displayed hydrolytic activity towards planteose and selectively acted on two tetrasaccharides,which were identified as sesamose and stachyose.In addition,transglycosylation property of LpαG using planteose led to the synthesis of sesamose.Thus,the hydrolysis of planteose and sesamose was demonstrated for the first time for anα-galactosidase from the probiotic bacterium.Furthermore,the oligosaccharides pool was shown to influence the growth of probiotic L.acidophilus,L.brevis and L.plantarum in vitro,along with the production of short chain fatty acids(SCFAs).These findings would contribute to the potential application of chia seeds to further enhance its health benefits.
基金funded by National Natural Science Foundation of China(project no.32272296)the National Key Research and Development Program of China(2017YFE0131800)+2 种基金Princess Nourah bint Abdulrahman University Researchers Supporting Project number(PNURSP2025R31)Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabiathe Deanship of Scientific Research(DSR)at King Faisal University under project no.[KFU250892]。
文摘Lactosucrose is a widely known prebiotic oligosaccharide,but it is synthesized generally with a low efficiency by using the available enzymes.To search for levansucrase(LS)for effective synthesis of lactosucrose has become a significant research challenge.In this study,LS was produced by Bacillus subtilis LG-4 isolated and identified from traditional natto,and it was separated and purified by ammonium sulfate fractionation and DEAE-Sepharose Fast Flow chromatography.It was further enzymatically characterized in terms of amino acid sequencing,optimum reaction conditions and kinetic parameters.The results showed that the LS(12.68 U/mL)was produced under the optimized fermentation conditions of 50 g/L sucrose,5 g/L soy peptone,10 g/L yeast extract,inoculation rate 2%,initial pH 6.5,at 37℃ for 20 h,and the kinetic models for LS production were also established.The LS was identified to be a GH 68 family protein(53 kDa),which was not reported earlier.It had an optimal pH of 6.5,and optimal temperatures of 40℃ and 45℃ for sucrose hydrolysis and transfructosylation activities,respectively.The enzyme showed good stability under the conditions of 35℃–45℃ and pH 6.0–7.0.The kinetic parameters were determined with Vmax of 54.65 mM/min and a relatively low Km value(18.69 mM),suggesting high affinity of the enzyme for substrate(sucrose).Lactosucrose(128.96 g/L)was effectively synthesized by using the LS at a higher productivity(368.88 g/L/h)than those reported in the literatures.Therefore,this study demonstrated a novel microbial LS with high prospects for industrial biosynthesis of lactosucrose.
基金supported by the special funds of agro-product quality safety risk assessment of Ministry of Agriculture of the People’s Republic of China(GJFP20191101).
文摘In the present study,the hydrolysis and acyltransferase activities of bifunctional feruloyl esterases DLFae4 were enhanced by a combination of multiple mutation strategies based on rationally predicting the potential beneficial mutation sites.Results showed that V149D&I172G was the strongest double mutant(589.67 U/mg),and the triple mutant N173G&N169G&I148G exhibited 3.60 and 5.57 times higher hydrolytic activity and catalytic efficiency towards MFA,respectively.Furthermore,the triple mutant releases 16.16 mg/g ferulic acid(FA)from de-starched wheat bran(DSWB)in synergy with xylanase,which was increased by 9.34 times than that released by DLFae4 alone,and was the highest reported release amount.The double mutant V251Y&A341G with weakened hydrolytic activity but exhibited 4.30 times higher acyltransferase activity than that of DLFae4,and the corresponding acyl transfer efficiency improved by 11.37 times,representing the highest acyltransferase activity to date.The results from the current investigation demonstrate that combining multiple rational design methods is a robust pipeline for improving enzyme activities and provides new insights for enzyme modification.
文摘Prodrug design is an important part of drug discovery.Prodrugs can offer many advantages over parent drugs such as increased solubility,enhanced stability,improved bioavailability,reduced side effects,and better selectivity.Many prodrugs have been used successfully in the clinic;examples include oseltamivir in anti-influenza therapy,enalapril in anti-hypertension therapy,capecitabine in cancer therapy,and omeprazole in the treatment of peptic ulcer.A key step in prodrug design is the incorporation of an activation mechanism that can convert the prodrug into the active species in an efficient and/or controlled manner to meet the needs of a given medical application.Prodrug activation can be achieved through enzyme-mediated hydrolytic or oxidoreductive processes while activation of some prodrugs may proceed through pure chemical nonenzymatic processes.This review focuses on the hydrolytic enzymes that have been used in prodrug activation,including transferases,hydrolases,and lyases.
