The objective of this study was to isolate and identify the intracellular bioactive peptides from mouse lymphocytes before and after lipopolysaccharide(LPS)stimulation,to explore novel peptides and to research the bio...The objective of this study was to isolate and identify the intracellular bioactive peptides from mouse lymphocytes before and after lipopolysaccharide(LPS)stimulation,to explore novel peptides and to research the bioactive function.Mouse spleen lymphocytes were isolated and cultured with LPS stimulation(experimental group)or not(control group)to collect intracellular peptides.Totally 385 peptides were analyzed by nanoliter liquid phase-Q Exactive quadrupole ultra-high resolution orbitrap mass spectrometer(Nano LC-Q Exactive Plus)and identifi ed by PEAKS X software.After compared with peptides reported,131 novel peptides were discovered,which then were predicted bioactivity by Peptide Ranker and 6 peptides with high bioactivity were predicted function by BIOPEP-UMW database.Prediction data showed that they may have dipeptidyl peptidase IV(DPP-IV)inhibitory activity.Finally,two peptides showed better potent inhibition were verifi ed with competitive and noncompetitive modes.展开更多
Synthetic exendin-4 exhibits dose-dependent glucose-regulatory activity similar to that of native glucagon-like peptide-1(GLP-1). Moreover, exendin-4 is resistant to degradation by dipeptidyl peptidase-Ⅳ(DPP-Ⅳ) whil...Synthetic exendin-4 exhibits dose-dependent glucose-regulatory activity similar to that of native glucagon-like peptide-1(GLP-1). Moreover, exendin-4 is resistant to degradation by dipeptidyl peptidase-Ⅳ(DPP-Ⅳ) while GLP-1 is degraded by DPP-Ⅳ with a half-life of less than 2 min in mammals. In this study the stability of exendin-4 in human plasma was evaluated in vitro. Exendin-4 was incubated in plasma at 37 ℃, extracted and subsequently analyzed by using high performance liquid chromatography(HPLC). Exendin-4 was slowly broken down in plasma. Its half-life time is 9.57 h. The degradation products were identified by mass-spectrum(MS). According to natural sequence of exendin-4, we deduced that the cleavage were between the Thr5 and Phe6 bond, Phe6 and Thr7 bond, and Thr7 and Ser8 bond of the N-terminus region of the peptide, and the results of ESI-TOF-MS prove that our primary conclusion was correct.展开更多
文摘The objective of this study was to isolate and identify the intracellular bioactive peptides from mouse lymphocytes before and after lipopolysaccharide(LPS)stimulation,to explore novel peptides and to research the bioactive function.Mouse spleen lymphocytes were isolated and cultured with LPS stimulation(experimental group)or not(control group)to collect intracellular peptides.Totally 385 peptides were analyzed by nanoliter liquid phase-Q Exactive quadrupole ultra-high resolution orbitrap mass spectrometer(Nano LC-Q Exactive Plus)and identifi ed by PEAKS X software.After compared with peptides reported,131 novel peptides were discovered,which then were predicted bioactivity by Peptide Ranker and 6 peptides with high bioactivity were predicted function by BIOPEP-UMW database.Prediction data showed that they may have dipeptidyl peptidase IV(DPP-IV)inhibitory activity.Finally,two peptides showed better potent inhibition were verifi ed with competitive and noncompetitive modes.
文摘Synthetic exendin-4 exhibits dose-dependent glucose-regulatory activity similar to that of native glucagon-like peptide-1(GLP-1). Moreover, exendin-4 is resistant to degradation by dipeptidyl peptidase-Ⅳ(DPP-Ⅳ) while GLP-1 is degraded by DPP-Ⅳ with a half-life of less than 2 min in mammals. In this study the stability of exendin-4 in human plasma was evaluated in vitro. Exendin-4 was incubated in plasma at 37 ℃, extracted and subsequently analyzed by using high performance liquid chromatography(HPLC). Exendin-4 was slowly broken down in plasma. Its half-life time is 9.57 h. The degradation products were identified by mass-spectrum(MS). According to natural sequence of exendin-4, we deduced that the cleavage were between the Thr5 and Phe6 bond, Phe6 and Thr7 bond, and Thr7 and Ser8 bond of the N-terminus region of the peptide, and the results of ESI-TOF-MS prove that our primary conclusion was correct.
