Zieleński J, Kościelak J
Eur J Biochem. 1982 Jul;125(2):323-9. doi: 10.1111/j.1432-1033.1982.tb06686.x.
A high galactosyltransferase activity with lactotriaosylceramide as acceptor has been found in human serums. The reaction requires UDP-galactose, Mn2+, and Triton X-100. It has a pH optimum of 6.0 and a Km for lactotriaosylceramide of 0.66 mM. On the basis of methylation analysis and susceptibility towards beta-galactosidase the reaction product has been identified as neolactotetraosylceramide. Lactotetraosylceramide formation was not observed. Evidence is presented that the serum enzymic activity can be attributed to N-acetyllactosamine synthase (EC 2.4.1.90). The beta 1 leads to 4-galactosyltransferase activities with lactotriaosylceramide as acceptor have been determined in different human sera. The activity is independent of ABO, p and Rh blood-group status. The enzyme is within a normal range in serums of cancer patients.
在人血清中发现了以乳糖三糖神经酰胺为受体时具有较高的半乳糖基转移酶活性。该反应需要尿苷二磷酸半乳糖、锰离子和曲拉通X-100。其最适pH为6.0，对乳糖三糖神经酰胺的米氏常数为0.66 mM。基于甲基化分析和对β-半乳糖苷酶的敏感性，反应产物已被鉴定为新乳糖四糖神经酰胺。未观察到乳糖四糖神经酰胺的形成。有证据表明，血清酶活性可归因于N-乙酰乳糖胺合酶（EC 2.4.1.90）。已测定了不同人血清中以乳糖三糖神经酰胺为受体时β1→4-半乳糖基转移酶的活性。该活性与ABO、p和Rh血型状态无关。该酶在癌症患者血清中的活性处于正常范围内。
