Genes encoding WFDC- and Kunitz-type protease inhibitor domains: are they related?

2011 ◽  
Vol 39 (5) ◽  
pp. 1398-1402 ◽  
Author(s):  
Åke Lundwall ◽  
Adam Clauss
Keyword(s):  
Human Chromosome ◽  
Protease Inhibitor ◽  
Protease Inhibitors ◽  
Trypsin Inhibitor ◽  
Bovine Pancreatic Trypsin Inhibitor ◽  
Sequence Motif ◽  
Genes Encoding ◽  
Pancreatic Trypsin Inhibitor ◽  
Kunitz Type ◽  
Kunitz Type Protease Inhibitor

We have previously demonstrated that the genes of SCPs (semen coagulum proteins) and the WFDC (whey acidic protein four-disulfide core)-type protease inhibitor elafin are homologous in spite of lacking similarity between their protein products. This led to the discovery of a locus on human chromosome 20, encompassing genes of the SCPs, SEMG1 (semenogelin I) and SEMG2, and 14 genes containing the sequence motif that is characteristic of WFDC-type protease inhibitors. We have now identified additional genes at the locus that are similarly organized, but which give rise to proteins containing the motif of Kunitz-type protease inhibitors. Here, we discuss the evolution of genes encoding SCPs and describe mechanisms by which they and genes with Kunitz motifs might have evolved from genes with WFDC motifs. We can also demonstrate an expansion of the WFDC locus with 0.6 Mb in the cow. The region, which seems to be specific to ruminants, contains several genes and pseudogenes with Kunitz motifs, one of which is the much-studied BPTI (bovine pancreatic trypsin inhibitor).

The Role of the P1 Residue of Protease Nexin 2 and Basic Pancreatic Trypsin Inhibitor in the Mechanism of Factor XIa Inhibition.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2015-2015
Author(s):  
Duraiswamy Navaneetham ◽  
Dipali Sinha ◽  
Peter N. Walsh
Keyword(s):  
Steady State ◽  
Protease Inhibitor ◽  
Trypsin Inhibitor ◽  
Tight Binding ◽  
Basic Pancreatic Trypsin Inhibitor ◽  
Factor Xia ◽  
Pancreatic Trypsin Inhibitor ◽  
Kunitz Type ◽  
Protease Nexin ◽  
Kunitz Type Protease Inhibitor

Abstract Factor XIa (FXIa), a plasma serine protease that activates FIX, is regulated by protease nexin 2 (PN2), a Kunitz-type protease inhibitor (KPI) secreted on platelet activation. The Kunitz protease inhibitor domain of protease nexin 2 (PN2KPI) is highly homologous (45% primary sequence identity) to basic pancreatic trypsin inhibitor (BPTI, another Kunitz-type protease inhibitor) and their backbone tertiary structures are nearly identical (J Biol Chem280: 36165, 2005; J Mol Biol230: 919, 2005). However, PN2KPI (Ki 1 nM) is 600-fold more potent as a FXIa inhibitor than bovine basic pancreatic trypsin inhibitor (BPTI; Ki 630 nM). The present study is aimed at examining why these two structurally similar inhibitors are so different in their affinities and specificities in FXIa inhibition and analyzing the mechanisms of FXIa inhibition by these two inhibitors. Reasoning that the P1 residue (Arg15 in PN2KPI and Lys15 in BPTI) might play a crucial role in determining the affinity and specificity for FXIa we expressed BPTI-K15R (mimicking PN2KPI at the P1 site) and PN2KPI-R15K (mimicking BPTI at the P1 site) and examined their inhibitory properties. BPTI-K15R was found to inhibit FXIa with a Ki (10 nM) ~60-fold tighter than BPTI (Ki 630 nM), whereas PN2KPI-R15K inhibited FXIa with a Ki (32 nM) that was 32- fold impaired compared with PN2KPI (Ki 1 nM). Progress curves of peptidyl fluorogenic substrate (Boc-Glu-Ala-Arg-AMC) hydrolysis by FXIa in the presence of all the inhibitors except BPTI clearly demonstrated higher initial rates that continuously decreased until reaching a steady state, typical of slow inhibition. Progress curves obtained using BPTI, on the other hand, were found to be linear at all concentrations of the inhibitor. Analysis using steady state kinetics clearly demonstrated that BPTI is a competitive inhibitor in FXIa hydrolysis of the peptidyl chromogenic substrate, pyro-Glu-Pro-Arg-pNA. Analysis of progress curves using kinetic equations for slow, tight-binding inhibitors confirmed that the formation of the FXIa:PN2KPI complex occurs in a single step that is slow, whereas formation of FXIa:PN2KPI-R15K, FXIa:BPTI and FXIa:BPTI-K15R complexes do not conform to the same kinetic mechanism. Thus PN2KPI and BPTI inhibit FXIa by distinctly different mechanisms and the Arg at the P1 site of PN2KPI confers specificity and high affinity for FXIa inhibition and in part determines the mechanism of PN2KPI as a slow, tight binding inhibitor.

scholarly journals Screening for Stable Mutants with Amino Acid Pairs Substituted for the Disulfide Bond between Residues 14 and 38 of Bovine Pancreatic Trypsin Inhibitor (BPTI)

2002 ◽  
Vol 277 (52) ◽  
pp. 51043-51048 ◽  
Author(s):  
Yoshihisa Hagihara ◽  
Kentaro Shiraki ◽  
Tsutomu Nakamura ◽  
Koichi Uegaki ◽  
Masahiro Takagi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Disulfide Bond ◽  
Trypsin Inhibitor ◽  
Bovine Pancreatic Trypsin Inhibitor ◽  
Pancreatic Trypsin Inhibitor

Synthetic Approaches to Disulfide-free Circular Bovine Pancreatic Trypsin Inhibitor (c-BPTI) Analogues

2006 ◽  
Vol 12 (2) ◽  
pp. 93-104 ◽  
Author(s):  
Judit Tulla-Puche ◽  
Irina V. Getun ◽  
Yvonne M. Angell ◽  
Jordi Alsina ◽  
Fernando Albericio ◽  
...  
Keyword(s):  
Trypsin Inhibitor ◽  
Bovine Pancreatic Trypsin Inhibitor ◽  
Pancreatic Trypsin Inhibitor ◽  
Synthetic Approaches

A Pulsed-Field Gradient NMR Study of Bovine Pancreatic Trypsin Inhibitor Self-Association†

Biochemistry ◽  
1997 ◽  
Vol 36 (11) ◽  
pp. 3383-3388 ◽  
Author(s):  
Elena Ilyina ◽  
Vikram Roongta ◽  
Hong Pan ◽  
Clare Woodward ◽  
Kevin H. Mayo
Keyword(s):  
Field Gradient ◽  
Trypsin Inhibitor ◽  
Bovine Pancreatic Trypsin Inhibitor ◽  
Pulsed Field Gradient Nmr ◽  
Pulsed Field ◽  
Nmr Study ◽  
Pancreatic Trypsin Inhibitor ◽  
Self Association
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