β-Lactam Antibiotics: Biochemical Modes of Action

摘要: Publisher Summary This chapter focuses on the biochemical modes of action β-lactam antibiotics. The antibiotics are quite complex. Penicillin and other β-lactams acylate several specific proteins, penicillin-binding to effect inhibition cell-wall assembly. PBPs include penicillin-sensitive enzymes involved in cross-linking step peptidoglycan biosynthesis. These catalyze transpeptidase, D-alanine carboxypeptidase, endopeptidase reactions vitro. Several high-molecular-weight might penicillin-insensitive transglycosylation disaccharide units too. A combination genetic techniques has been applied better define vivo functions PBPs. substrate same active-site serine residue each two carboxypeptidases, accord with analog hypothesis for mechanism penicillin action. X-ray crystallographic studies progress should help elucidate detailed mechanisms by which inhibit sensitive enzymes. Penicillin-induced cell lysis involves factors, most important is participation endogenous autolytic outer membrane gram-negative bacteria poses a formidable penetration barrier antibiotics, compounding factors that influence effectiveness these compounds as antimicrobial agents.