Kinetics of the competitive reactions of isomerization and peptide bond cleavage atl-α- andd-β-aspartyl residues in an αA-crystallin fragment

2016 ◽  
Vol 23 (1) ◽  
pp. 28-37 ◽  
Author(s):  
Kenzo Aki ◽  
Emiko Okamura
Keyword(s):  
Bond Cleavage ◽  
Peptide Bond ◽  
Peptide Bond Cleavage ◽  
Competitive Reactions ◽  
Kinetics Of

Demasking kinetics of peptide bond cleavage for whey protein isolate hydrolysed by Bacillus licheniformis protease

2016 ◽  
Vol 133 ◽  
pp. S426-S431 ◽  
Author(s):  
Mikhail M. Vorob’ev ◽  
Claire I. Butré ◽  
Stefano Sforza ◽  
Peter A. Wierenga ◽  
Harry Gruppen
Keyword(s):  
Whey Protein ◽  
Bacillus Licheniformis ◽  
Bond Cleavage ◽  
Peptide Bond ◽  
Whey Protein Isolate ◽  
Protein Isolate ◽  
Peptide Bond Cleavage ◽  
Kinetics Of

scholarly journals Kringles of substrate plasminogen provide a ‘catalytic switch' in plasminogen to plasmin turnover by Streptokinase

2020 ◽  
Vol 477 (5) ◽  
pp. 953-970
Author(s):  
Vandna Sharma ◽  
Shekhar Kumar ◽  
Girish Sahni
Keyword(s):  
Chemical Transformation ◽  
Active Site ◽  
Catalytic Domain ◽  
Bond Cleavage ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Peptide Bond ◽  
Peptide Bond Cleavage ◽  
Catalytic Processing ◽  
Kinetics Of

To understand the role of substrate plasminogen kringles in its differential catalytic processing by the streptokinase — human plasmin (SK-HPN) activator enzyme, Fluorescence Resonance Energy Transfer (FRET) model was generated between the donor labeled activator enzyme and the acceptor labeled substrate plasminogen (for both kringle rich Lys plasminogen — LysPG, and kringle less microplasminogen — µPG as substrates). Different steps of plasminogen to plasmin catalysis i.e. substrate plasminogen docking to scissile peptide bond cleavage, chemical transformation into proteolytically active product, and the decoupling of the nascent product from the SK-HPN activator enzyme were segregated selectively using (1) FRET signal as a proximity sensor to score the interactions between the substrate and the activator during the cycle of catalysis, (2) active site titration studies and (3) kinetics of peptide bond cleavage in the substrate. Remarkably, active site titration studies and the kinetics of peptide bond cleavage have shown that post docking chemical transformation of the substrate into the product is independent of kringles adjacent to the catalytic domain (CD). Stopped-flow based rapid mixing experiments for kringle rich and kringle less substrate plasminogen derivatives under substrate saturating and single cycle turnover conditions have shown that the presence of kringle domains adjacent to the CD in the macromolecular substrate contributes by selectively speeding up the final step, namely the product release/expulsion step of catalysis by the streptokinase-plasmin(ogen) activator enzyme.

scholarly journals Serine protease dynamics revealed by NMR analysis of the thrombin-thrombomodulin complex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Riley B. Peacock ◽  
Taylor McGrann ◽  
Marco Tonelli ◽  
Elizabeth A. Komives
Keyword(s):  
Active Site ◽  
Serine Proteases ◽  
Protein C ◽  
Catalytic Mechanism ◽  
Bond Cleavage ◽  
Peptide Bond ◽  
Peptide Bond Cleavage ◽  
Exchange Mass Spectrometry ◽  
Catalytically Active ◽  
Hydrogen Deuterium

AbstractSerine proteases catalyze a multi-step covalent catalytic mechanism of peptide bond cleavage. It has long been assumed that serine proteases including thrombin carry-out catalysis without significant conformational rearrangement of their stable two-β-barrel structure. We present nuclear magnetic resonance (NMR) and hydrogen deuterium exchange mass spectrometry (HDX-MS) experiments on the thrombin-thrombomodulin (TM) complex. Thrombin promotes procoagulative fibrinogen cleavage when fibrinogen engages both the anion binding exosite 1 (ABE1) and the active site. It is thought that TM promotes cleavage of protein C by engaging ABE1 in a similar manner as fibrinogen. Thus, the thrombin-TM complex may represent the catalytically active, ABE1-engaged thrombin. Compared to apo- and active site inhibited-thrombin, we show that thrombin-TM has reduced μs-ms dynamics in the substrate binding (S1) pocket consistent with its known acceleration of protein C binding. Thrombin-TM has increased μs-ms dynamics in a β-strand connecting the TM binding site to the catalytic aspartate. Finally, thrombin-TM had doublet peaks indicative of dynamics that are slow on the NMR timescale in residues along the interface between the two β-barrels. Such dynamics may be responsible for facilitating the N-terminal product release and water molecule entry that are required for hydrolysis of the acyl-enzyme intermediate.

Activation of Bovine Factor V by Thrombin and A Protease From Russell's Viper Venom (RVV)

1979 ◽  
Author(s):  
M.J. Lindhout ◽  
C. M. Jackson
Keyword(s):  
Bond Cleavage ◽  
Peptide Bond ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Factor V ◽  
Peptide Bond Cleavage ◽  
Prothrombinase Complex ◽  
Factor Va ◽  
Activation Products ◽  
Ca Oxalate

In order to understand the function of activated factor V in the prothrombinase complex, we isolated the activation products obtained by action of thrombin and RVV-V on factor V and studied their functional properties. Factor V isolated from plasma by means of ion-exchange chromatography, a Ca-oxalate adsorption step and gelfiltration was homogenous in SDS-gelelectrophoresis (apparent MW 360,000, with and without reduction). Increase in factor V activity upon action by RVV-V is correlated with a single peptide bond cleavage, resulting in a 270,000 dalton and a 80,000 dalton component. Additional proteolysis of factor Va(RVV/V)’ by thrombin results in a further cleavage of the high MW component into peptides with MW's of 72,000, 94,000 and about 150,000 without a furth~r increase in factor V activity. Whereas none of the isolated peptides reveal factor Va activity, activity would be generated by a recombination in the presence of Ca2+ of the 94,000 MW or 270,000 MW component with the 80,000 component. Action of thrombin alone on factor V results in peptides of MW 72,000, 80,000, 94,000 and a peptide very rich in carbohydrate with an apparent MW of 150,000.

ChemInform Abstract: Unusual Peptide Bond Cleavage Reactions During Acidolytic Deprotection Reactions.

ChemInform ◽  
2010 ◽  
Vol 24 (28) ◽  
pp. no-no
Author(s):  
J. R. SPENCER ◽  
N. G. J. DELAET ◽  
A. TOY-PALMER ◽  
V. V. ANTONENKO ◽  
M. GOODMAN
Keyword(s):  
Bond Cleavage ◽  
Peptide Bond ◽  
Peptide Bond Cleavage ◽  
Cleavage Reactions

scholarly journals Specific peptide-bond cleavage by microwave irradiation in weak acid solution

1992 ◽  
Vol 11 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Chi-Yue Wu ◽  
Shui-Tein Chen ◽  
Shyh-Horng Chiou ◽  
Kung-Tsung Wang
Keyword(s):  
Microwave Irradiation ◽  
Acid Solution ◽  
Bond Cleavage ◽  
Peptide Bond ◽  
Weak Acid ◽  
Peptide Bond Cleavage ◽  
Specific Peptide
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