Bernal A, Mercado E, Calzada L, Hicks J J
Arch Androl. 1983 Aug;11(1):33-8. doi: 10.3109/01485018308987457.
3H-sialyl residues transfer by subcellular epididymal fractions [plasma membrane (PM), microsomes (MI), and mitochondria (MT)] to both endogenous and exogenous acceptors was studied. Their fraction purity was valued (5' nucleotidase and glucose 6-phosphatase activities). The glycoprotein or glycolipid N-acetyl neuraminyl transferase activity in microsomes were 5 times higher in caput than in cauda (624 to 125 pmoles/30 min/mg protein). PM activity also was higher in caput. In MT fraction, the activity was smaller. Two mechanisms related to spermatozoa glycoprotein changes during maturation are proposed: secretion to the lumen of molecules previously glycosilated in microsomes and transialylation to spermatozoa from membranal ectoenzymes localized on the surface of the epididymal epithelium.
研究了附睾亚细胞组分[质膜(PM)、微粒体(MI)和线粒体(MT)]将3H-唾液酸残基转移至内源性和外源性受体的情况。评估了它们的组分纯度(5'-核苷酸酶和葡萄糖6-磷酸酶活性)。微粒体中糖蛋白或糖脂N-乙酰神经氨酸转移酶活性在附睾头比附睾尾高5倍(624至125皮摩尔/30分钟/毫克蛋白)。质膜活性在附睾头也较高。在线粒体组分中，活性较小。提出了与精子成熟过程中糖蛋白变化相关的两种机制：分泌先前在微粒体中糖基化的分子至管腔，以及附睾上皮表面定位的膜外酶对精子进行转唾液酸化。
