IV. Acyl-CoA: 6-APA acyltransferase of Penicillium chrysogenum: studies on substrate specificity using phenylacetyl-CoA variants.
Two different penicillins (p- and m-methylbenzylpenicillin) were obtained "in vitro" by direct enzymatic synthesis, using homogeneously pure acyl-CoA: 6-aminopenicillanic acid (6-APA) acyltransferase from Penicillium chrysogenum, 6-APA and p- or m-tolylacetyl-CoA. The Km for these substrates were 6 and 15 mM, respectively, indicating that the affinity of the enzyme for these two molecules is much lower that shown by phenylacetyl-CoA (0.55 mM). Furthermore, acyltransferase does not recognize o-tolylacetyl-CoA as a substrate suggesting that the position of the methyl group on the aromatic moiety may have a very important role in the formation of the enzyme-substrate complex.
Martín-Villacorta
J
J
Departamento de Bioquímica y Biología Molecular, Universidad de León, España.
Reglero
A
A
Luengo
J M
JM
D000105:Acetyl Coenzyme A / Q000378:metabolism; D000214:Acyl Coenzyme A / Q000378:metabolism; D000217:Acyltransferases / Q000378:metabolism*; D010397:Penicillanic Acid / Q000378:metabolism* / Q000031:analogs & derivatives; D046915:Penicillin-Binding Proteins; D010407:Penicillium / Q000201:enzymology*; D010408:Penicillium chrysogenum / Q000201:enzymology*; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D000214:Acyl Coenzyme A; D046915:Penicillin-Binding Proteins; C061487:3-tolylacetyl-coenzyme A; C061486:2-tolylacetyl-coenzyme A; C061488:4-tolylacetyl-coenzyme A; D000105:Acetyl Coenzyme A; C037816:phenylacetyl-coenzyme A; D010397:Penicillanic Acid; D000217:Acyltransferases; C018756:acyl-CoA-6-aminopenicillanic acid acyltransferase; C004408:aminopenicillanic acid