Binding of benzyl penicilloyl to human serum albumin. Evidence for a highly reactive region at the junction of domains 1 and 2 of the albumin molecule.

Tryptic digests of fragment C124-298 of penicilloylated serum albumin, obtained from a penicillin-treated patient or prepared by in vitro conjugation, were analyzed by HPLC. Determinations of benzyl penicilloyl groups (BPO) were performed on the different fractions. Three BPO-containing peptides were identified by their amino acid sequence and the bound BPO was located on lysines 190, 195 and 199 and serine 193. These four main BPO-binding sites are all located on a very short region (10 amino acid residues) of the albumin molecule at the junction of domains 1 and 2.