The vital role of D-danine and L-lysine in the peptidoglycan crosslinking process in the bacterial cell wall prompted preparation of various small peptides incorporating these amino acids. N-Iodoacetyl or-bromoacetyl derivatives of the peptides were then prepared in the hope that they would serve as active-site-directed irreversible inhibitors of cell wall transpeptidases. Certain of the halogenoacetyl dipeptide esters, but not the corresponding ...