Yang Y S, Marshall A D, McPhie P, Guo W X, Xie X, Chen X, Jakoby W B
Section on Enzymes, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
Protein Expr Purif. 1996 Dec;8(4):423-9. doi: 10.1006/prep.1996.0120.
A phenol sulfotransferase from rat liver (EC 2.8.2.9), expressed in Escherichia coli from a single cDNA, was purified as two separable but catalytically active proteins. The proteins appeared to be identical to each other and to the natural liver sulfotransferase by comparison of their amino acid constitution, amino-terminal end group, and interaction with a polyclonal antibody raised against the liver enzyme. Each of the recombinant forms, alpha and beta, catalyzed the sulfuryl group transfer from 4-nitrophenylsulfate to an acceptor phenol, a reaction in which 3'-phospho-adenosine 5'-phosphate (PAP) is a necessary intermediate. Only form beta, however, catalyzes the physiological transfer of a sulfuryl group from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to the free phenol. Evidence is presented that sulfotransferase alpha, but not beta, has 1 mol of PAP tightly bound per enzyme dimer. The ability to utilize PAPS as a sulfate donor could be altered: form alpha could be treated and purified as form beta to acquire the ability to use PAPS, whereas form beta was treated by extended incubation with PAP, lost its ability to use PAPS, and was purified as form alpha.
一种来自大鼠肝脏的酚磺基转移酶（EC 2.8.2.9），由单个cDNA在大肠杆菌中表达，被纯化得到两种可分离但具有催化活性的蛋白质。通过比较它们的氨基酸组成、氨基末端基团以及与针对肝脏酶产生的多克隆抗体的相互作用，这两种蛋白质似乎彼此相同且与天然肝脏磺基转移酶相同。重组形式的α和β各自催化硫酸根从4-硝基苯硫酸酯转移至受体酚，此反应中3'-磷酸腺苷5'-磷酸（PAP）是必要的中间体。然而，只有β形式催化硫酸根从3'-磷酸腺苷5'-磷酰硫酸（PAPS）向游离酚的生理转移。有证据表明，磺基转移酶α而非β，每个酶二聚体紧密结合1摩尔PAP。利用PAPS作为硫酸供体的能力可以改变：α形式可以按照β形式处理和纯化以获得使用PAPS的能力，而β形式通过与PAP长时间孵育处理后，失去使用PAPS的能力，并按照α形式纯化。
