it was hypothesized ( tipper , d. , and strominger , j . ( 1965 ) proc . natl . acad . sci . u.s.a. 54 , 1133-1141 ) that 1 ) penicillin is a structural analog of the acyl-d-alanyl-d-alanine terminus of the pentapeptide side chains of nascent peptidoglycan , and that 2 ) penicillin , by virtue of its highly reactive beta-lactam structure , irreversibly acylates the active site of the cell wall transpeptidase .
C0030842
penicillin
C0282215
beta-lactam