Leach M, Cameron E, Fite N, Stassinopoulos J, Palmreuter N, Beckmann J D
Department of Biochemistry, Alma College, 614 W. Superior Street, Alma, Michigan, 48801, USA.
Biochem Biophys Res Commun. 1999 Aug 11;261(3):815-9. doi: 10.1006/bbrc.1999.1096.
Phenol sulfotransferases (PSTs, EC 2.8.2.1) catalyze sulfonyl group transfer from 3'-phosphoadenosine-5'-phosphosulfate (PAPS) to the hydroxyl oxygen of aromatic acceptor substrates. The structural overlap between PAPS and coenzyme A (CoA) suggested a possible role of this common acyl carrier in modulating PST activity. To test this hypothesis, purified recombinant bovine PST was examined by kinetic and affinity chromatographic approaches. After demonstrating PST enzyme inhibition by CoA, systematic variation of CoA and PAPS concentrations indicated simple competitive inhibition with K(i) = 1. 3 microM. PST bound to CoA-agarose, attached via the pantetheinyl thiol group, was eluted with PAP but not by 2-naphthol. This observation was consistent with the pattern of inhibition. Additional members of the sulfotransferase superfamily, as well as acylated CoAs, should be further investigated.
酚磺基转移酶（PSTs，EC 2.8.2.1）催化3'-磷酸腺苷-5'-磷酸硫酸酯（PAPS）中的磺酰基转移至芳香族受体底物的羟基氧上。PAPS与辅酶A（CoA）之间的结构重叠表明这种常见的酰基载体可能在调节PST活性中发挥作用。为了验证这一假设，采用动力学和亲和色谱法对纯化的重组牛PST进行了研究。在证实CoA对PST酶有抑制作用后，CoA和PAPS浓度的系统变化表明存在简单竞争性抑制，抑制常数K(i) = 1.3 microM。通过泛酰巯基连接到CoA-琼脂糖上的PST，用PAP洗脱，但不能用2-萘酚洗脱。这一观察结果与抑制模式一致。磺基转移酶超家族的其他成员以及酰化CoA应进一步研究。
