Habuchi O, Miyata K
Biochim Biophys Acta. 1980 Dec 4;616(2):208-17. doi: 10.1016/0005-2744(80)90139-4.
A soluble glycosaminoglycan sulfotransferase (3'-phosphoadenylylsulfate:chondroitin 4'-sulfotransferase, EC 2.8.2.5) from chick embryo cartilage has been prepared free from endogenous acceptor. The reaction with this enzyme preparation was stimulated by basic proteins and polyamines, the degree of stimulation being dependent on the chemical nature of both basic compounds and acceptor glycosaminoglycans. A maximum stimulation was obtained when protamine (basic compound) and chondroitin (acceptor) were involved in the reaction mixture at a molar ratio of protamine to repeating disaccharide units of chondroitin, 1:100. The stimulation of sulfotransferase activity by basic substances was much higher than that by Mn2+. However, increasing the Mn2+ concentration immediately reduced the stimulation by basic substances. The Km value for 3'-phosphoadenosine 5'-phosphosulfate of the sulfotransferase, when chondroitin was used as acceptor, was 1 . 10(-6) M in the presence of 25 microgram/ml protamine, compared to 2 . 10(-5) M in the absence of protamine. These observations indicate that the basic proteins and polyamines may interact with acceptor polysaccharide, thereby causing an increase in the affinity of the enzyme toward 3'-phosphoadenosine 5'-phosphosulfate.
已从鸡胚软骨中制备出一种不含内源性受体的可溶性糖胺聚糖硫酸转移酶（3'-磷酸腺苷硫酸：软骨素4'-硫酸转移酶，EC 2.8.2.5）。碱性蛋白质和多胺可刺激该酶制剂的反应，刺激程度取决于碱性化合物和受体糖胺聚糖的化学性质。当鱼精蛋白（碱性化合物）和软骨素（受体）以鱼精蛋白与软骨素重复二糖单位的摩尔比为1:100参与反应混合物时，可获得最大刺激。碱性物质对硫酸转移酶活性的刺激远高于Mn2+。然而，增加Mn2+浓度会立即降低碱性物质的刺激作用。当以软骨素为受体时，在存在25微克/毫升鱼精蛋白的情况下，硫酸转移酶对3'-磷酸腺苷5'-磷酸硫酸的Km值为1×10^(-6) M，而在不存在鱼精蛋白的情况下为2×10^(-5) M。这些观察结果表明，碱性蛋白质和多胺可能与受体多糖相互作用，从而导致酶对3'-磷酸腺苷5'-磷酸硫酸的亲和力增加。
