Water-Soluble Class C β-Lactamase Catalytic Residue Mimic: Effect of Proximally Positioned Functional Groups on their pKa Values
摘要:
Molecules mimicing class C beta-lactamase catalytic residues were synthesized to study the effect of proximal positioning of serine, lysine and tyrosine side chains on their pKa values. The three amino acid side chains were mimicked by hydroxymethyl group, alkyl ammonium group and phenol which were linked by a short skeleton to ensure interaction among these functionalities. Comparison of the mimics in water showed a phenolic pKa decrease of up to 3.6 units. The finding supports the possible role of tyrosine as a general acid/base catalyst in acylation of class C beta-lactamase. (C) 1997 Elsevier Science Ltd. All rights reserved.