This paper reported the identification of the primary structure of two peptides using nanoelectrospray tandem mass spectrometry(Nano-ESI MS/MS).Firstly,the relative molecular mass of two peptides were determined in ES...This paper reported the identification of the primary structure of two peptides using nanoelectrospray tandem mass spectrometry(Nano-ESI MS/MS).Firstly,the relative molecular mass of two peptides were determined in ESI-TOF MS mode.Then fragmentation ions were obtained by selecting [M+2H]2+ ion using tandem mass spectrometry(MS/MS).Finally,the primary structure of triptorelin is determined to be E’HWSYWLRPG’,of which the N-terminal is pyroglutamic acid (E’) and the C-termianl is glycinamide (G’).The primary structure of unknown peptide was identified to be T’VSP VWLPPSVY by sequence docking method,of which the N-terminal occurs threonine phosphorylation (T’) and the foruth proline is added with sodium ion (P).The data suggested that electrospray Tandem mass spectrometry technique have obvious advantage in analyzing the full sequence of modified or unknown peptides.展开更多
The primary structure of atosiban(an artificially synthesized 8AA peptide) was confirmed by nanoelectrospray tandem mass spectrometry.Accurate relative molecular mass of atosiban unreduced and reduced were determined ...The primary structure of atosiban(an artificially synthesized 8AA peptide) was confirmed by nanoelectrospray tandem mass spectrometry.Accurate relative molecular mass of atosiban unreduced and reduced were determined firstly by full-scan mass spectrometry,and fragmentation ions were obtained by selecting parental ions m/z 498.73(double charge) using mass spectrometry(MS/MS).The sequence and modified site of atosiban was designated by using y ion method.The method is sensitive,fast and simple,and can provide a great valuable information for confirmation of primary structure of polypeptide drugs.展开更多
Xiao-Xu-Ming decoction has been widely used to treat stroke and sequelae of stroke. We have previously shown that the active fractions of Xiao-Xu-Ming decoction attenuate cerebral ischemic injury. However, the global ...Xiao-Xu-Ming decoction has been widely used to treat stroke and sequelae of stroke. We have previously shown that the active fractions of Xiao-Xu-Ming decoction attenuate cerebral ischemic injury. However, the global protein profile and signaling conduction pathways regulated by Xiao-Xu-Ming decoction are still unclear. This study established a two-vessel occlusion rat model by bilateral common carotid artery occlusion. Rats were intragastrically administered 50 or 150 mg/kg Xiao-Xu-Ming decoction for 4 consecutive weeks. Learning and memory abilities were measured with Morris water maze. Motor ability was detected with prehensile test. Coordination ability was examined using the inclined screen test. Neuronal plasticity was observed by immunofluorescent staining. Differentially expressed proteins of rat hippocampus were analyzed by label-free quantitative proteomics. Real time-polymerase chain reaction and western blot assay were used to identify the changes in proteins. Results showed that Xiao-Xu-Ming decoction dramatically alleviated learning and memory deficits, and motor and coordination dysfunction, and increased the expression of microtubule-associated protein 2. Xiao-Xu-Ming decoction extract remarkably decreased 13 upregulated proteins and increased 39 downregulated proteins. The regulated proteins were mainly involved in oxidation reduction process, intracellular signaling cascade process, and protein catabolic process. The signaling pathways were mainly involved in ubiquitin mediated proteolysis and the phosphatidylinositol signaling system. Furthermore, there was an interaction among Rab2 a, Ptpn1, Ppm1 e, Cdk18, Gorasp2, Eps15, Capza2, Syngap1 and Mt-nd1. Protein analyses confirmed the changes in expression of MTND1. The current findings provide new insights into the molecular mechanisms of Xiao-Xu-Ming decoction extract's effects on chronic cerebral hypoperfusion.展开更多
文摘This paper reported the identification of the primary structure of two peptides using nanoelectrospray tandem mass spectrometry(Nano-ESI MS/MS).Firstly,the relative molecular mass of two peptides were determined in ESI-TOF MS mode.Then fragmentation ions were obtained by selecting [M+2H]2+ ion using tandem mass spectrometry(MS/MS).Finally,the primary structure of triptorelin is determined to be E’HWSYWLRPG’,of which the N-terminal is pyroglutamic acid (E’) and the C-termianl is glycinamide (G’).The primary structure of unknown peptide was identified to be T’VSP VWLPPSVY by sequence docking method,of which the N-terminal occurs threonine phosphorylation (T’) and the foruth proline is added with sodium ion (P).The data suggested that electrospray Tandem mass spectrometry technique have obvious advantage in analyzing the full sequence of modified or unknown peptides.
文摘The primary structure of atosiban(an artificially synthesized 8AA peptide) was confirmed by nanoelectrospray tandem mass spectrometry.Accurate relative molecular mass of atosiban unreduced and reduced were determined firstly by full-scan mass spectrometry,and fragmentation ions were obtained by selecting parental ions m/z 498.73(double charge) using mass spectrometry(MS/MS).The sequence and modified site of atosiban was designated by using y ion method.The method is sensitive,fast and simple,and can provide a great valuable information for confirmation of primary structure of polypeptide drugs.
基金supported in part by the National Natural Science Foundation of China,No.81473383(to YHW)the Significant New-Drugs Creation of Science and Technology Major Projects in China,No.2018ZX09711001-003-019(to YHW)the Innovation Fund for Graduate of Beijing Union Medical College of China,No.2017-1007-02(to XC)
文摘Xiao-Xu-Ming decoction has been widely used to treat stroke and sequelae of stroke. We have previously shown that the active fractions of Xiao-Xu-Ming decoction attenuate cerebral ischemic injury. However, the global protein profile and signaling conduction pathways regulated by Xiao-Xu-Ming decoction are still unclear. This study established a two-vessel occlusion rat model by bilateral common carotid artery occlusion. Rats were intragastrically administered 50 or 150 mg/kg Xiao-Xu-Ming decoction for 4 consecutive weeks. Learning and memory abilities were measured with Morris water maze. Motor ability was detected with prehensile test. Coordination ability was examined using the inclined screen test. Neuronal plasticity was observed by immunofluorescent staining. Differentially expressed proteins of rat hippocampus were analyzed by label-free quantitative proteomics. Real time-polymerase chain reaction and western blot assay were used to identify the changes in proteins. Results showed that Xiao-Xu-Ming decoction dramatically alleviated learning and memory deficits, and motor and coordination dysfunction, and increased the expression of microtubule-associated protein 2. Xiao-Xu-Ming decoction extract remarkably decreased 13 upregulated proteins and increased 39 downregulated proteins. The regulated proteins were mainly involved in oxidation reduction process, intracellular signaling cascade process, and protein catabolic process. The signaling pathways were mainly involved in ubiquitin mediated proteolysis and the phosphatidylinositol signaling system. Furthermore, there was an interaction among Rab2 a, Ptpn1, Ppm1 e, Cdk18, Gorasp2, Eps15, Capza2, Syngap1 and Mt-nd1. Protein analyses confirmed the changes in expression of MTND1. The current findings provide new insights into the molecular mechanisms of Xiao-Xu-Ming decoction extract's effects on chronic cerebral hypoperfusion.
