Galactosyltransferase activity is restricted to the plasma membranes of equine and bovine sperm.
Galactosyltransferase activity is restricted to the plasma membranes of equine and bovine sperm.
复制标题
半乳糖基转移酶活性仅限于马和牛精子的质膜。
DOI：
10.1002/mrd.1080280112
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发表时间：
1991
影响因子：
2.5
通讯作者：
Shur,BD
中科院分区：
文献类型：
--
作者：
Fayrer-Hosken,RA;Caudle,AB;Shur,BD
β 1,4‐半乳糖转移酶（GalTase）定位于小鼠精子的质膜，介导精子与卵细胞透明带中糖缀合物残基的结合。在这项研究中，在另外两种产生足够精子进行亚细胞分离的哺乳动物物种中，确定了精子GalTase的存在和亚细胞分布。采集马和牛精液，依次去除质膜（PM）、顶体外膜（OAM）和顶体内膜（IAM）。通过透射电镜测定分离膜制剂的纯度，发现马PM、OAM和IAM的纯度分别为≥90%、96%和98%，牛PM、OAM和IAM的纯度分别为≥80%、94%和97%。在最佳条件下测定了所有膜制剂的半乳糖酶活性，并在马和牛精子中优先定位于分离的PM。在另外两个物种中，GalTase在精子PM上的选择性定位表明，它可能在哺乳动物最初的精子-卵子结合过程中作为一种普遍的配子受体。
β1, 4‐Galactosyltransferase (GalTase) is localized to the plasma membrane of mouse sperm, in which it mediates the binding of sperm to glycoconjugate residues in the egg zona pellucida. In this study, the presence and subcellular distribution of sperm GalTase were determined in two other mammalian species that yield sufficient sperm for subecellular fractionation. Equine and bovine semen were collected, and the plasma membranes (PM), outer acrosomal membranes (OAM), and inner acrosomal membranes (IAM) were sequentially removed. The purities of the isolated membrane preparations were determined by transmission electron microscopy and found to be ≥90%, 96%, and 98% for equine PM, OAM, and IAM, respectively, and ≥80%, 94%, and 97% for bovine PM, OAM, and IAM, respectively. GalTase activity was assayed under optimal conditions in all membrane preparations and was preferentially localized to the isolated PM both in equine and in bovine spermatozoa. The selective localization of GalTase to the sperm PM in two other species suggest that it may serve as a generalized gamete receptor during initial sperm–egg binding in mammals.