Kasinathan C, Sundaram P, Slomiany B L, Slomiany A
Research Center, University of Medicine and Dentistry of New Jersey, Newark.
Enzyme. 1992;46(4-5):179-87. doi: 10.1159/000468786.
An enzyme activity which catalyzes the transfer of the sulfate group from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to poly-Glu6,Ala3,Tyr1 (EAY; M(r) 47,000) has been demonstrated in the antral and body mucosa of the rat stomach. The distribution of this tyrosylprotein sulfotransferase was similar to that of the Golgi marker enzyme, glycoprotein sulfotransferase, and its activity from body mucosa was 23% higher than that from the antrum. The optimum for tyrosylprotein sulfotransferase activity was obtained at pH 6.8, in the presence of 0.5% Triton X-100, 20 mmol/l MnCl2, 50 mmol/l NaF, 2 mmol/l 5'-AMP, and 1 mmol/l DTT, whereas Ca2+, Mg2+, Cu2+, Zn2+, EDTA, NEM, NaCl and Na2SO4 were inhibitory. The apparent Km of the sulfotransferase for EAY was 1.5 x 10(-6) mol/l and for PAPS 0.75 x 10(-6) mol/l. The enzyme was 28 times less susceptible to 2,6-dichloro-4-nitrophenol inhibition as compared to that required for phenol sulfotransferase inhibition. The tyrosine sulfation by the tyrosylprotein sulfotransferase was independent of the sulfation of carbohydrate residues in mucous glycoproteins and glycolipids, thus indicating that the identified sulfotransferase is specific for sulfation of the tyrosyl residues in the peptide core.
在大鼠胃窦和胃体黏膜中已证实存在一种酶活性，该酶可催化将硫酸基团从3'-磷酸腺苷5'-磷酸硫酸酯（PAPS）转移至聚 - Glu6，Ala3，Tyr1（EAY；相对分子质量47,000）。这种酪氨酰蛋白硫酸转移酶的分布与高尔基体标记酶糖蛋白硫酸转移酶相似，其在胃体黏膜中的活性比胃窦中的高23%。酪氨酰蛋白硫酸转移酶活性的最适条件为pH 6.8，存在0.5% Triton X - 100、20 mmol/L MnCl2、50 mmol/L NaF、2 mmol/L 5'-AMP和1 mmol/L DTT，而Ca2+、Mg2+、Cu2+、Zn2+、EDTA、NEM、NaCl和Na2SO4具有抑制作用。该硫酸转移酶对EAY的表观Km为1.5×10^(-6) mol/L，对PAPS为0.75×10^(-6) mol/L。与酚硫酸转移酶抑制所需浓度相比，该酶对2,6 - 二氯 - 4 - 硝基苯酚抑制的敏感性低至1/28。酪氨酰蛋白硫酸转移酶介导的酪氨酸硫酸化与黏液糖蛋白和糖脂中碳水化合物残基的硫酸化无关，这表明所鉴定的硫酸转移酶对肽核心中酪氨酰残基的硫酸化具有特异性。
