JBIC Journal of Biological Inorganic Chemistry

, Volume 11, Issue 7, pp 937–947

Metallopeptide-promoted inactivation of angiotensin-converting enzyme and endothelin-converting enzyme 1: toward dual-action therapeutics

Authors

  • Nikhil H. Gokhale
    • Evans Laboratory of ChemistryOhio State University
    • Evans Laboratory of ChemistryOhio State University
Original Paper

DOI: 10.1007/s00775-006-0145-2

Cite this article as:
Gokhale, N.H. & Cowan, J.A. J Biol Inorg Chem (2006) 11: 937. doi:10.1007/s00775-006-0145-2

Abstract

A series of metallopeptides based on the amino terminal copper/nickel (ATCUN) binding motif have been evaluated as classical inhibitors and catalytic inactivators of both rabbit and human angiotensin-converting enzyme (hACE), and human endothelin-converting enzyme 1 (hECE-1). The cobalt complex [KGHK–Co(NH3)2]2+, where KGHK is lysylglycylhistidyllysine, displayed similar KI and IC50 values to those found for [KGHK–Cu]+, in spite of the enhanced charge, and so either the influence of charge is offset by the steric influence of the axially coordinated ammine ligands, or binding is dominated by contributions from the amino acid side chains, especially the C-terminal lysine that mimics the binding pattern observed for lisinopril. Moreover, the inhibition observed for [KGHK–Co(NH3)2]2+ contrasts with the activation of hACE by Co2+(aq), reflecting the stimulation of enzyme activity following replacement of the catalytic zinc cofactor by cobalt ion at each of the two active sites. Quantitative analysis of the dose-dependent stimulation of activity by Co2+(aq) yielded apparent affinities of 1.3 ± 0.2 and 56 ± 8 μM for the two sites in the presence of saturating Zn2+ (10 μM). Catalytic inactivation of hACE by [KGHK–Cu] + at subsaturating concentrations had previously been characterized, with kobs = 2.9 ± 0.5 × 10−2 min−1. Under similar conditions, the same complex is found to catalytically inactivate hECE-1, with kobs = 2.12 ± 0.16 × 10−2 min−1, demonstrating the potential for dual-action activity against two key drug targets in cardiovascular disease. Irreversible inactivation of a drug target represents a novel mechanism of drug action that complements existing classical inhibitor strategies that underlie current drug discovery efforts.

Keywords

ATCUNAngiotensin-converting enzymeEndothelin-converting enzyme 1Drug designCatalytic inactivation

Supplementary material

775_2006_145_MOESM1_ESM.doc (1.3 mb)
Supplementary material

Copyright information

© SBIC 2006