Chymotryptic specificity determinants in the 1.0 Å structure of the zinc-inhibited human tissue kallikrein 7
| Autor: | Peter Goettig, Mekdes Debela, Robert Huber, Wolfram Bode, Norman M. Schechter, Viktor Magdolen, Petra Hess, Thomas Steiner |
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| Jazyk: | angličtina |
| Rok vydání: | 2007 |
| Předmět: |
Models
Molecular Serine Proteinase Inhibitors Tissue kallikrein Molecular Sequence Data Static Electricity In Vitro Techniques Crystallography X-Ray Substrate Specificity Serine Catalytic Domain Hydrolase Catalytic triad Chymotrypsin Humans Amino Acid Sequence Multidisciplinary biology Sequence Homology Amino Acid Stratum corneum chymotryptic enzyme Kallikrein Biological Sciences Molecular biology Recombinant Proteins Kinetics Zinc Biochemistry biology.protein Kallikreins Copper |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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