EMAIL THIS PAGE TO A FRIEND

The Journal of biological chemistry

Structure-function analyses of human kallikrein-related peptidase 2 establish the 99-loop as master regulator of activity.


PMID 25326387

Abstract

Human kallikrein-related peptidase 2 (KLK2) is a tryptic serine protease predominantly expressed in prostatic tissue and secreted into prostatic fluid, a major component of seminal fluid. Most likely it activates and complements chymotryptic KLK3 (prostate-specific antigen) in cleaving seminal clotting proteins, resulting in sperm liquefaction. KLK2 belongs to the "classical" KLKs 1-3, which share an extended 99- or kallikrein loop near their non-primed substrate binding site. Here, we report the 1.9 Å crystal structures of two KLK2-small molecule inhibitor complexes. In both structures discontinuous electron density for the 99-loop indicates that this loop is largely disordered. We provide evidence that the 99-loop is responsible for two biochemical peculiarities of KLK2, i.e. reversible inhibition by micromolar Zn(2+) concentrations and permanent inactivation by autocatalytic cleavage. Indeed, several 99-loop mutants of KLK2 displayed an altered susceptibility to Zn(2+), which located the Zn(2+) binding site at the 99-loop/active site interface. In addition, we identified an autolysis site between residues 95e and 95f in the 99-loop, whose elimination prevented the mature enzyme from limited autolysis and irreversible inactivation. An exhaustive comparison of KLK2 with related structures revealed that in the KLK family the 99-, 148-, and 220-loop exist in open and closed conformations, allowing or preventing substrate access, which extends the concept of conformational selection in trypsin-related proteases. Taken together, our novel biochemical and structural data on KLK2 identify its 99-loop as a key player in activity regulation.

Related Materials

Product #

Image

Description

Molecular Formula

Add to Cart

31653
Zinc, puriss. p.a., ACS reagent, reag. ISO, reag. Ph. Eur., ≥99.9%, granular
Zn
96454
Zinc, purum, powder
Zn
209988
Zinc, dust, <10 μm, ≥98%
Zn
349410
Zinc, foil, thickness 1.0 mm, 99.99% trace metals basis
Zn
349429
Zinc, foil, thickness 0.5 mm, 99.999%
Zn
267619
Zinc, foil, thickness 0.25 mm, 99.999% trace metals basis
Zn
267600
Zinc, foil, thickness 0.1 mm, 99.999%
Zn
356018
Zinc, foil, thickness 0.25 mm, 99.9% trace metals basis
Zn
565148
Zinc, granular, −30 mesh±100, 99%
Zn
266345
Zinc, granular, −10-+50 mesh, ≥99.8%, ACS reagent
Zn
243469
Zinc, granular, 20-30 mesh, ACS reagent, ≥99.8%
Zn
243477
Zinc, ACS reagent, −30-+100 mesh, ≥99.8%, granular
Zn
215503
Zinc, mossy, 99.99% trace metals basis
Zn
215481
Zinc, mossy, ≥99%
Zn
578002
Zinc, nanopowder, 40-60 nm avg. part. size, ≥99% trace metals basis
Zn
266353
Zinc, pieces, 2-14 mesh, 99.9% trace metals basis
Zn
324930
Zinc, powder, <150 μm, 99.995% trace metals basis
Zn
267635
Zinc, shot, 5 mm, 99.999% trace metals basis
Zn
402583
Zinc, shot, <12 mm, 99.99% trace metals basis
Zn
266361
Zinc, sticks, diam. 7-10 mm, 99.97% trace metals basis
Zn
267929
Zinc, wire, diam. 1.0 mm, 99.999% trace metals basis
Zn
355976
Zinc, wire, diam. 0.25 mm, 99.999%
Zn
716723
Zinc, shot, 99.9999%
Zn
749060
Zinc, sputtering target, diam. × thickness 3.00 in. × 0.125 in., 99.995% trace metals basis
Zn
GF60963453
Zinc, wire reel, 0.5m, diameter 0.5mm, as drawn, 99.99+%
Zn
GF58911385
Zinc, wire reel, 0.5m, diameter 1.0mm, 99.99+%
Zn
GF57898760
Zinc, wire reel, 0.5m, diameter 1.0mm, 99.999%
Zn
GF72904327
Zinc, wire reel, 0.5m, diameter 2.0mm, 99.99+%
Zn
GF88622107
Zinc, wire reel, 0.5m, diameter 6.35mm, 99.99+%
Zn
GF37287704
Zinc, wire reel, 100m, diameter 0.25mm, as drawn, 99.99+%
Zn