Enzymatic synthesis of glucocerebroside by a glucosyltransferase from embryonic chicken brain.
Enzymatic synthesis of glucocerebroside by a glucosyltransferase from embryonic chicken brain.
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通过来自胚胎鸡脑的葡萄糖基转移酶酶促合成葡萄糖脑苷脂。
DOI：
10.1016/s0021-9258(19)44311-1
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发表时间：
1973
期刊：
影响因子：
--
通讯作者：
S. Roseman
中科院分区：
文献类型：
--
作者：
S. Basu;B. Kaufman;S. Roseman
从13 ~ 14日龄胚鸡脑中分离到一种催化神经酰胺（n -酰基鞘氨醇）和udp -葡萄糖合成葡萄糖神经酰胺（葡萄糖脑苷）的葡萄糖基转移酶。反应如下：神经酰胺+ UDP-葡萄糖→糖基神经酰胺（+ UDP）神经酰胺是最有效的脂质受体，各种潜在给体都不能替代UDP-葡萄糖。神经酰胺和UDP-[14C]葡萄糖的km值分别为0.08 mm和0.12 mm。金属离子对反应无刺激作用，四乙酸乙二胺对反应无抑制作用。udp -葡萄糖：神经酰胺葡萄糖基转移酶的颗粒制备对洗涤剂有绝对的要求，以Cutscum和Triton X-100的混合物为最佳活性。早在7日龄的鸡胚的大脑中就检测到葡萄糖基转移酶；在胚胎发育的第13 ~ 17天达到最大活性。这种酶催化合成神经节苷的第一步。
A glucosyltransferase that catalyzes the synthesis of glucosylceramide (glucocerebroside) from ceramide (N-acylsphingosine) and UDP-glucose was isolated from 13- to 14-day-old embryonic chicken brain. The reaction is the following:Ceramide + UDP-glucose → glucosylceramide (+ UDP)Ceramide was the most effective lipid acceptor, and a variety of potential donors could not replace UDP-glucose. TheKmvalues for ceramide and UDP-[14C]glucose were 0.08 mmand 0.12 mm, respectively. Metal ions did not stimulate the reaction, and it was not inhibited by ethylenediaminetetraacetate. The particulate preparation of UDP-glucose:ceramide glucosyltransferase showed an absolute requirement for detergent, and optimal activity was obtained with a mixture of Cutscum and Triton X-100.The glucosyltransferase was detectable in brains from chick embryos as early as 7 days old; maximal activity was detected between 13 and 17 days of embryonic development. The enzyme catalyzes the first step in the synthesis of gangliosides.