In this study we systematically analyzed the elution condition of tryptic peptides and the characteristics of identi?ed peptides in reverse phase liquid chromatogra- phy and electrospray tandem mass spectrometry (RPLC...In this study we systematically analyzed the elution condition of tryptic peptides and the characteristics of identi?ed peptides in reverse phase liquid chromatogra- phy and electrospray tandem mass spectrometry (RPLC-MS/MS) analysis. Fol- lowing protein digestion with trypsin, the peptide mixture was analyzed by on-line RPLC-MS/MS. Bovine serum albumin (BSA) was used to optimize acetonitrile (ACN) elution gradient for tryptic peptides, and Cytochrome C was used to retest the gradient and the sensitivity of LC-MS/MS. The characteristics of identi?ed peptides were also analyzed. In our experiments, the suitable ACN gradient is 5% to 30% for tryptic peptide elution and the sensitivity of LC-MS/MS is 50 fmol. Analysis of the tryptic peptides demonstrated that longer (more than 10 amino acids) and multi-charge state (+2, +3) peptides are likely to be identi?ed, and the hydropathicity of the peptides might not be related to whether it is more likely to be identi?ed or not. The number of identi?ed peptides for a protein might be used to estimate its loading amount under the same sample background. Moreover, in this study the identi?ed peptides present three types of redundancy, namely iden- ti?cation, charge, and sequence redundancy, which may repress low abundance protein identi?cation.展开更多
Leucyl-tRNA synthetase (LeuRS, EC 6.1.1.4) from E. coli underwent limitedproteolysis by trypsin which cut off 6K peptide and converted the intact LeuRS into a 96K fragment. The truncated enzyme retained the PPi exchan...Leucyl-tRNA synthetase (LeuRS, EC 6.1.1.4) from E. coli underwent limitedproteolysis by trypsin which cut off 6K peptide and converted the intact LeuRS into a 96K fragment. The truncated enzyme retained the PPi exchange activity with the same kinetic parameters as those of native LeuRS but lost the tRNA^(Leu)charging, binding and other tRNA^(Leu)-related activities. N-terminus analysis showed that the 6K peptide was located at the C-terminus of LeuRS. This small part played a crucial role in tRNA^(Leu) binding. Our results suggest that the two activities, PPi exchange and tRNA charging are independent of each other and correspond to different structural regions of LeuRS. The C-terminal region might be the tRNA^(Leu)binding site of LeuRS.展开更多
Diabetes mellitus is an incurable disease, so it is necessary to establish a model to screen biomarkers for early warning in order to minimize the likelihood of long-term complications. Current- ly, advanced glycation...Diabetes mellitus is an incurable disease, so it is necessary to establish a model to screen biomarkers for early warning in order to minimize the likelihood of long-term complications. Current- ly, advanced glycation end products （AGEs） are considered to be biomarkers of many diseases, such as diabetes and its complications. In this study, a model for further proteomics study was es- tablished to analyze the glycation of HSA with 18 O-labeling strategy. 30 peptides were randomly se- lected to optimize tryptic digestion and 18O-labeling condition by HPLC-ESI/TOF. The best tryptic di- gestion condition was： HSA： Trypsin = 50： 1, w/w for 20 h. The best t8 O-labeling condition was to di- lute urea to 1 M and adjust KH2 POa--K2 HPO4 buffer pH to 6.0 to give a final labeling efficiency of 98.5 ± 0.7%. The inter- and intra-day precisions and stability were satisfactory. This model was es- tablished and optimized for further quantitative proteomics study.展开更多
Wind-induced sand erosion is a natural process, and can have several negative impacts on human health, environment, and economy. To mitigate the wind-induced sand erosion, an environmental friendly technique that help...Wind-induced sand erosion is a natural process, and can have several negative impacts on human health, environment, and economy. To mitigate the wind-induced sand erosion, an environmental friendly technique that helps to bind soil particles is desirable. The microbially induced calcium carbonate precipitation(MICP) treatment has lately become renowned and a viable alternative to enhance the binding of sand particles(especially against wind erosion). The efficiency of Sporosarcina pasteurii bacteria in inducing calcite formation can be influenced by various factors, including the type of growth media used for bacterial culture. Most of the studies have mainly validated the efficiency of S. pasteurii bacteria usually under single growth media for the MICP treatment. However, the efficiency of S. pasteurii under different growth media on calcite formation is rarely explored. The current study explores the effect of S.pasteurii bacteria on calcite formation under the presence of three different growth media, namely,molasses(MS), tryptic soy broth(TB), and nutrient broth(NB). The three growth media have been applied in the laboratory with and without bacterial solution(control samples). Altered cementation media concentrations(0.5 and 1.0 M) with different pore volumes(PVs), namely, 0.25, 0.50, and 1.00 PV were used in sand-filled tubes for 7 and 14 treatment cycles(1 cycle=24 h). The pH and EC were measured for 12-h period in every 2 h interval, to monitor values at the time of treatment at room temperature. The calcite precipitation was confirmed using SEM(scanning electron microscope), PXRD(powder X-ray diffraction), and calcimeter tests. It was observed that MS generates lower calcite precipitation as compared with NB and TB. However, MS has the advantage of being more economical and abundant(waste product from sugar mills and refineries) as compared with other growth media(NB and TB). It was observed that the minimum and the maximum calcite precipitation using MS is 5% and 12%, respectively.The findings using MS in the present study was compared with the literature and found that precipitation of calcite using MS is effective to stabilize soil against wind erosion.展开更多
基金This work was partially supported by grants fromthe National Basic Research Program (973) of China(2004CB520804), and National Natural Science Foun-dation of China (No. 30270657, 30230150, 3037030).
文摘In this study we systematically analyzed the elution condition of tryptic peptides and the characteristics of identi?ed peptides in reverse phase liquid chromatogra- phy and electrospray tandem mass spectrometry (RPLC-MS/MS) analysis. Fol- lowing protein digestion with trypsin, the peptide mixture was analyzed by on-line RPLC-MS/MS. Bovine serum albumin (BSA) was used to optimize acetonitrile (ACN) elution gradient for tryptic peptides, and Cytochrome C was used to retest the gradient and the sensitivity of LC-MS/MS. The characteristics of identi?ed peptides were also analyzed. In our experiments, the suitable ACN gradient is 5% to 30% for tryptic peptide elution and the sensitivity of LC-MS/MS is 50 fmol. Analysis of the tryptic peptides demonstrated that longer (more than 10 amino acids) and multi-charge state (+2, +3) peptides are likely to be identi?ed, and the hydropathicity of the peptides might not be related to whether it is more likely to be identi?ed or not. The number of identi?ed peptides for a protein might be used to estimate its loading amount under the same sample background. Moreover, in this study the identi?ed peptides present three types of redundancy, namely iden- ti?cation, charge, and sequence redundancy, which may repress low abundance protein identi?cation.
基金Project supported by the National Natural Science Foundation of China. Part of the results was presented at the 4th Congress of FAOB (Federation of Asian and Oceanian Biochemists) in 1986.
文摘Leucyl-tRNA synthetase (LeuRS, EC 6.1.1.4) from E. coli underwent limitedproteolysis by trypsin which cut off 6K peptide and converted the intact LeuRS into a 96K fragment. The truncated enzyme retained the PPi exchange activity with the same kinetic parameters as those of native LeuRS but lost the tRNA^(Leu)charging, binding and other tRNA^(Leu)-related activities. N-terminus analysis showed that the 6K peptide was located at the C-terminus of LeuRS. This small part played a crucial role in tRNA^(Leu) binding. Our results suggest that the two activities, PPi exchange and tRNA charging are independent of each other and correspond to different structural regions of LeuRS. The C-terminal region might be the tRNA^(Leu)binding site of LeuRS.
基金Supported by the National Key Technology R&D Program of China(2012YQ040140,2012CB91060)the National Natural Science Foundation of China(21205005)
文摘Diabetes mellitus is an incurable disease, so it is necessary to establish a model to screen biomarkers for early warning in order to minimize the likelihood of long-term complications. Current- ly, advanced glycation end products （AGEs） are considered to be biomarkers of many diseases, such as diabetes and its complications. In this study, a model for further proteomics study was es- tablished to analyze the glycation of HSA with 18 O-labeling strategy. 30 peptides were randomly se- lected to optimize tryptic digestion and 18O-labeling condition by HPLC-ESI/TOF. The best tryptic di- gestion condition was： HSA： Trypsin = 50： 1, w/w for 20 h. The best t8 O-labeling condition was to di- lute urea to 1 M and adjust KH2 POa--K2 HPO4 buffer pH to 6.0 to give a final labeling efficiency of 98.5 ± 0.7%. The inter- and intra-day precisions and stability were satisfactory. This model was es- tablished and optimized for further quantitative proteomics study.
基金the Prestige Institute of Engineering, Management, and Research (PIEMR), Indore, India, for their support during the research work。
文摘Wind-induced sand erosion is a natural process, and can have several negative impacts on human health, environment, and economy. To mitigate the wind-induced sand erosion, an environmental friendly technique that helps to bind soil particles is desirable. The microbially induced calcium carbonate precipitation(MICP) treatment has lately become renowned and a viable alternative to enhance the binding of sand particles(especially against wind erosion). The efficiency of Sporosarcina pasteurii bacteria in inducing calcite formation can be influenced by various factors, including the type of growth media used for bacterial culture. Most of the studies have mainly validated the efficiency of S. pasteurii bacteria usually under single growth media for the MICP treatment. However, the efficiency of S. pasteurii under different growth media on calcite formation is rarely explored. The current study explores the effect of S.pasteurii bacteria on calcite formation under the presence of three different growth media, namely,molasses(MS), tryptic soy broth(TB), and nutrient broth(NB). The three growth media have been applied in the laboratory with and without bacterial solution(control samples). Altered cementation media concentrations(0.5 and 1.0 M) with different pore volumes(PVs), namely, 0.25, 0.50, and 1.00 PV were used in sand-filled tubes for 7 and 14 treatment cycles(1 cycle=24 h). The pH and EC were measured for 12-h period in every 2 h interval, to monitor values at the time of treatment at room temperature. The calcite precipitation was confirmed using SEM(scanning electron microscope), PXRD(powder X-ray diffraction), and calcimeter tests. It was observed that MS generates lower calcite precipitation as compared with NB and TB. However, MS has the advantage of being more economical and abundant(waste product from sugar mills and refineries) as compared with other growth media(NB and TB). It was observed that the minimum and the maximum calcite precipitation using MS is 5% and 12%, respectively.The findings using MS in the present study was compared with the literature and found that precipitation of calcite using MS is effective to stabilize soil against wind erosion.
