2qxi

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spinqualitylabelsall models 2qxi, resolution 1.000Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

High resolution structure of Human Kallikrein 7 in Complex with Suc-Ala-Ala-Pro-Phe-chloromethylketone

Overview

hK7 or human stratum corneum chymotryptic enzyme belongs to the human, tissue kallikrein (hKs) serine proteinase family and is strongly expressed, in the upper layers of the epidermis. It participates in skin desquamation, but is also implicated in diverse skin diseases and is a potential, biomarker of ovarian cancer. We have solved x-ray structures of, recombinant active hK7 at medium and atomic resolution in the presence of, the inhibitors succinyl-Ala-Ala-Pro-Phe-chloromethyl ketone and, Ala-Ala-Phe-chloromethyl ketone. The most distinguishing features of hK7, are the short 70-80 loop and the unique S1 pocket, which prefers P1 Tyr, residues, as shown by kinetic data. Similar to several other kallikreins, the enzyme activity is inhibited by Zn(2+) and Cu(2+) at low micromolar, concentrations. Biochemical analyses of the mutants H99A and H41F confirm, that only the metal-binding site at His(99) close to the catalytic triad, accounts for the noncompetitive Zn(2+) inhibition type. Additionally, hK7, exhibits large positively charged surface patches, representing putative, exosites for prime side substrate recognition.

About this Structure

2QXI is a Single protein structure of sequence from Homo sapiens with as ligand. Active as Stratum corneum chymotryptic enzyme, with EC number 3.4.21.117 Full crystallographic information is available from OCA.

Reference

Chymotryptic specificity determinants in the 1.0 A structure of the zinc-inhibited human tissue kallikrein 7., Debela M, Hess P, Magdolen V, Schechter NM, Steiner T, Huber R, Bode W, Goettig P, Proc Natl Acad Sci U S A. 2007 Oct 9;104(41):16086-91. Epub 2007 Oct 1. PMID:17909180

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