Enzymatic synthesis of penicillins.
Different penicillins (phenylacetyl, 2-hydroxyphenylacetyl, 4-hydroxyphenylacetyl, phenoxyacetyl and 2-thiopheneacetylpenicillin) have been synthesized "in vitro" by direct N-acylation of 6-aminopenicillanic acid (6-APA) with the acyl group of several acyl-CoA derivatives. The enzyme that catalyzes these reactions, acyl-CoA: 6-APA acyltransferase of Penicillium chrysogenum, was purified to homogeneity (374-fold) and its amino acid composition is given. This protein accepts as substrates several aliphatic acids and different aromatic acids with the only requirement that an acetyl-CoA moiety must be present in the substrate molecule. Shortening or lengthening of the acyl moiety prevents the 6-APA-N-acylation reaction. The presence of an amino group in the alpha-position of the acetyl group does not allow this molecule to be used as substrate. However, different substitutions in the phenyl group (hydroxylation of the carbons 2 and 4) or its replacement by another aromatic ring (thiophene) were accepted with varying reactions rates in the acylation reaction when a 176-fold purified acyltransferase was employed. The homogeneity pure enzyme accepts as substrate thiophene acetyl-CoA but it did not 2-hydroxyphenyl and 4-hydroxyphenylacetyl-CoA. The presence of an oxygen atom between the aromatic and the acetyl moieties did not affect the catalysis.
Alonso
M J
MJ
Departamento de Bioquímica y Biología Molecular, Universidad de León, España.
Bermejo
F
F
Reglero
A
A
Fernández-Cañón
J M
JM
González de Buitrago
G
G
Luengo
J M
JM
D000217:Acyltransferases / Q000302:isolation & purification*; D000596:Amino Acids / Q000302:isolation & purification; D002384:Catalysis; D008970:Molecular Weight; D046915:Penicillin-Binding Proteins; D010406:Penicillins / Q000096:biosynthesis*; D010407:Penicillium / Q000201:enzymology*; D013379:Substrate Specificity
D000596:Amino Acids; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D000217:Acyltransferases; C018756:acyl-CoA-6-aminopenicillanic acid acyltransferase