Luengo J M, Iriso J L, López-Nieto M J
J Antibiot (Tokyo). 1986 Nov;39(11):1565-73. doi: 10.7164/antibiotics.39.1565.
The enzyme phenylacetyl-CoA: 6-Aminopenicillanic acid acyltransferase of Penicillium chrysogenum was evaluated by direct bioassay against Micrococcus luteus ATCC 9341. The enzyme required dithiothreitol, was inactivated by 0.2 mM Hg2+ (100%), Zn2+ (80%), Cu2+ (60%), 1 mM N-ethylmaleimide (80%), and showed maximal catalytic activity at pH 8.4 and 20 degrees C. The V50 values for phenylacetyl-CoA and 6-aminopenicillanic acid were 0.55 mM and 1 microM, respectively. When octanoyl-CoA was employed as substrate similar results were obtained. In both cases the product generated showed strong antibacterial activity which was quickly lost when incubation was carried out with beta-lactamase. Reactions performed in the presence of Escherichia coli penicillin acylase did not generated active products when phenylacetyl-CoA was the substrate; they did with octanoyl-CoA. Time-course experiments revealed that the highest enzyme levels are found in 36 hours mycelium and remained almost constant from 48 to 96 hours; thereafter the level of the enzyme slowly decreased.
通过针对藤黄微球菌ATCC 9341的直接生物测定法，对产黄青霉的苯乙酰辅酶A：6-氨基青霉烷酸酰基转移酶进行了评估。该酶需要二硫苏糖醇，会被0.2 mM Hg2+（100%）、Zn2+（80%）、Cu2+（60%）、1 mM N-乙基马来酰亚胺（80%）灭活，并且在pH 8.4和20℃时表现出最大催化活性。苯乙酰辅酶A和6-氨基青霉烷酸的V50值分别为0.55 mM和1 microM。当使用辛酰辅酶A作为底物时，获得了类似的结果。在这两种情况下，产生的产物均表现出很强的抗菌活性，当与β-内酰胺酶一起孵育时，该活性会迅速丧失。当以苯乙酰辅酶A为底物时，在大肠杆菌青霉素酰化酶存在下进行的反应不会产生活性产物；而以辛酰辅酶A为底物时则会产生。时间进程实验表明，在36小时的菌丝体中发现酶水平最高，从48小时到96小时几乎保持恒定；此后，酶水平缓慢下降。
