1iy7

File:1iy7.gif

Crystal Structure of CPA and sulfamide-based inhibitor complex

Overview

N-Sulfamoylphenylalanine and its derivatives having varied alkyl groups on the terminal amino group were designed rationally as transition state analogue inhibitors for carboxypeptidase A (CPA) and synthesized. In CPA inhibitory assays the parent compound having the (S)-configuration, i.e., (S)-1a, showed potent inhibitory activity with the K(i) value of 0.64 microM. Its enantiomer was shown to be much less potent (K(i) = 470 microM). Introduction of an alkyl group such as methyl or isopropyl group on the terminal amino group of (S)-1a lowered the inhibitory potency drastically. Introduction of a methyl group on the internal amino group of (S)-1a also caused a drastic reduction of the inhibitory activity. The structure of the CPA x(S)-1a complex determined by single-crystal X-ray diffraction reveals that the sulfamoyl moiety interacts with the zinc ion and functional groups at the active site of CPA, which is reminiscent of the postulated stabilization mode of a tetrahedral transition state in the CPA-catalyzed hydrolysis of a peptide substrate. On the basis of the design rationale and the binding mode of (S)-1a to CPA shown by X-ray crystallographic analysis, the present inhibitors are inferred to be a novel type of transition state analogue inhibitor for CPA.

About this Structure

1IY7 is a Single protein structure of sequence from Bos taurus. Full crystallographic information is available from OCA.

Reference

Sulfamide-based inhibitors for carboxypeptidase A. Novel type transition state analogue inhibitors for zinc proteases., Park JD, Kim DH, Kim SJ, Woo JR, Ryu SE, J Med Chem. 2002 Nov 21;45(24):5295-302. PMID:12431056 Page seeded by OCA on Fri May 2 20:34:18 2008

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