Galactose transfer to endogenous acceptors within Golgi fractions of rat liver.
Galactose transfer to endogenous acceptors within Golgi fractions of rat liver.
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DOI：
10.1083/jcb.92.1.139
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发表时间：
1982-01
期刊：
影响因子：
--
通讯作者：
Paiement J
中科院分区：
文献类型：
--
作者：
Bergeron JJ;Rachubinski RA;Sikstrom RA;Posner BI;Paiement J
半乳糖转移酶的分布是通过对Ehrenreich等人的方法（1973年）进行修改而分离出的反式和顺式高尔基体来研究的。J.细胞生物学，59:45-72)以及通过新的一步法分离的完整高尔基体片段。采用两种测定方法。第一种方法分析了高尔基体部分将半乳糖（从尿苷二磷酸半乳糖[UDP-gal]底物）转移到确定的外源性受体卵黏液样物的能力。第二种方法评估了半乳糖从UDP-gal底物到内源性受体的转移（内源性糖基化）。反式高尔基馏分（高尔基光）在第一种方法中表现为高活性，而在第二种方法中表现为低活性。富含中心元素和顺式元素的高尔基体组分（高尔基体中间体，重质，尤其是完整的高尔基体组分）在两种分析方法中都具有高度活性。内源性糖基化方法通过内源性受体的凝胶荧光图验证。对于所有高尔基体馏分，半乳糖的转移显示为分泌糖肽。由此得出，体内半乳糖转移酶活性主要发生在中央和顺式高尔基体中，而不发生在反式高尔基体中。
The distribution of galactosyl transferase was studied using trans and cis Golgi fractions isolated by a modification of the Ehrenreich et al. procedure (1973. J. Cell Biol. 59:45-72) as well as an intact Golgi fraction isolated by a new one-step procedure. Two methods of assay were used. The first method analyzed the ability of Golgi fractions to transfer galactose (from uridine diphosphogalactose [UDP-gal] substrate) to the defined exogenous acceptor ovomucoid. The second method assessed the transfer of galactose from UDP-gal substrate to endogenous acceptors (endogenous glycosylation). The trans Golgi fraction (Golgi light) was highly active by the first method but revealed only low activity by the second method. Golgi fractions enriched in central and cis elements (the Golgi intermediate, heavy and especially the intact Golgi fraction) were highly active in both methods of assay. The endogenous glycosylation approach was validated by gel fluorography of the endogenous acceptors. For all Golgi fractions, transfer of galactose was revealed to secretory glycopeptides. It is concluded that galactosyl transferase activity in vivo occurs primarily in central and cis Golgi elements but not trans Golgi vesicles.