Substrate specificity of immobilized penicillin-G acylase towards penicillin and cephalosporin derivatives was studied. The phenylacetyl moiety can be altered at the α-position with several small substituents. Depending on polarity and size of the substituent, enzyme activity decreases or increases. Insertion or deletion of atoms between the aromatic nucleus of the phenylacetyl group and the center of hydrolysis leads to substrates that are no longer recognized by the enzyme.

Substrate specificity of immobilized penicillin-G acylase towards penicillin and cephalosporin derivatives was studied. The phenylacetyl moiety can be altered at the α-position with several small substituents. Depending on polarity and size of the substituent, enzyme activity decreases or increases. Insertion or deletion of atoms between the aromatic nucleus of the phenylacetyl group and the center of hydrolysis leads to substrates that are no longer recognized by the enzyme. Structure-activity relations in cephalosporins prepared from penicillins. 1. 7.beta.-Acylamino derivatives of 3-benzyl- and 3-(3-pyridylmethyl)ceph-3-em-4-carboxylic acids Substrate specificity of isopenicillin N synthase Quantification of the extent of attenuation of the rate of turnover chemistry of the TEM-1 β-lactamase by the α-1R-hydroxyethyl group in substrates A “cephalosporin-like” cyclic depsipeptide: Synthesis and reaction with ß-lactam-recognizing enzymes Synthesis and biological activity of some broad-spectrum N-acylphenylglycine cephalosporins Penicillin inhibitors of purple acid phosphatase Penicillin biosynthesis: direct biosynthetic formation of penicillin V and penicillin G The role of arginine residues in substrate binding and catalysis by deacetoxycephalosporin C synthase Penicillin biosynthesis: multiple pathways from a modified substrate