Open AccessCharacterization of the Co 2+ and Ni 2+ binding amino‐acid residues of the N‐terminus of human albumin
Author(s) -
BarOr David,
Curtis Gerald,
Rao Nagaraja,
Bampos Nick,
Lau Edward
Publication year - 2001
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.2001.01846.x
Subject(s) - human serum albumin , amino acid , peptide , binding site , acetylation , cobalt , chemistry , albumin , biochemistry , peptide sequence , plasma protein binding , stereochemistry , organic chemistry , gene
Patients suffering from myocardial ischemia reportedly exhibit reduced in vitro binding of exogenous Co 2+ to the N‐terminal of human serum albumin (HSA). The purpose of our investigation was to simulate changes in the N‐terminus of HSA that may account for these ischemia‐induced modifications to the cobalt binding site. HPLC, LC‐MS and 1 H NMR analyses have shown that the N‐terminal region of HSA Asp‐Ala‐His‐Lys binds the transition metals Co 2+ and Ni 2+ . Synthetic peptides with the first 2–12 amino acids of the HSA sequence demonstrated that the first three amino acids, Asp‐Ala‐His, are essential for strong binding of cobalt. Modification of the N‐terminus peptide of HSA by way of N‐acetylation or the deletion of one or more amino acid resulted in no binding of cobalt. Because the degradation of the susceptible, specific transition metal binding site of HSA may account for the decreased cobalt binding observed during ischemic events, an assay that detects this reduced binding could be useful in the diagnosis of ischemia.