附睾成熟过程中山羊精子质膜的脂质变化

Lipid changes of goat sperm plasma membrane during epididymal maturation.

作者信息

Rana A P, Majumder G C, Misra S, Ghosh A

机构信息

Indian Institute of Chemical Biology, Calcutta.

出版信息

Biochim Biophys Acta. 1991 Jan 30;1061(2):185-96. doi: 10.1016/0005-2736(91)90284-f.

DOI:10.1016/0005-2736(91)90284-f

PMID:1998692

Abstract

Highly purified plasma membranes of maturing goat caput-, corpus- and cauda-epididymal spermatozoa were isolated by aqueous two-phase polymer methods and their lipid constituents were analysed. Phospholipid (approx. 75% w/w), neutral lipid (approx. 15% w/w) and glycolipid (approx. 10% w/w) were the major sperm membrane lipids. There was a significant decrease in the total lipids (approx. 25% w/w), phospholipid (approx. 30% w/w) and glycolipid (approx. 80% w/w) contents of sperm membrane during epididymal maturation. On the contrary, the mature cauda-sperm membrane showed greater (approx. 50% w/w) neutral lipid content than that of the immature caput sperm. Phosphatidylcholine (PC), phosphatidylethanolamine (PE) and sphingomyelin were the phospholipids of the sperm membrane, the former two being the major lipids. Both PC and PE fractions consisted of three species--diacyl, alkylacyl and alkenylacyl forms, the last one being the dominant species in both PC and PE. Of all the phospholipids, diacyl PE decreased most strikingly (approx. 65% w/w) during sperm maturation. The neutral lipid fraction contained sterols, wax esters, 1-O-alkyl-2,3-diacylglycerol, triacylglycerol and fatty acids. Sterols represented nearly 75% w/w of the neutral lipids and cholesterol was the major component (approx. 95% w/w) of the sterol fraction. The sperm maturity was associated with marked increase of sterol (approx. 60% w/w) and steryl ester (approx. 200% w/w) and decrease (approx. 50-65% w/w) of the other membrane-bound neutral lipids. The glycolipid was identified as monogalactosyldiacylglycerol. The fatty acid profile of the various membrane lipids underwent marked alteration during the epididymal transit of the male gametes. Cholesterol/phospholipid and saturated/unsaturated fatty acid ratios increased greatly in the maturing sperm membrane. The altered lipid profile of the mature sperm membrane leads to changes in its fluidity that play an important role in determining the structure and functions of the biomembrane.

摘要

采用双水相聚合物方法分离了成熟山羊附睾头、附睾体和附睾尾精子的高度纯化质膜，并对其脂质成分进行了分析。磷脂（约75% w/w）、中性脂质（约15% w/w）和糖脂（约10% w/w）是精子膜的主要脂质。在附睾成熟过程中，精子膜的总脂质（约25% w/w）、磷脂（约30% w/w）和糖脂（约80% w/w）含量显著下降。相反，成熟的附睾尾精子膜的中性脂质含量（约50% w/w）比未成熟的附睾头精子更高。磷脂酰胆碱（PC）、磷脂酰乙醇胺（PE）和鞘磷脂是精子膜的磷脂，前两者是主要脂质。PC和PE组分均由三种形式组成——二酰基、烷基酰基和烯基酰基形式，最后一种在PC和PE中均为主要形式。在精子成熟过程中，所有磷脂中，二酰基PE下降最为显著（约65% w/w）。中性脂质组分包含固醇、蜡酯、1-O-烷基-2,3-二酰甘油、三酰甘油和脂肪酸。固醇占中性脂质的近75% w/w，胆固醇是固醇组分的主要成分（约95% w/w）。精子成熟与固醇（约60% w/w）和固醇酯（约200% w/w）的显著增加以及其他膜结合中性脂质的减少（约50 - 65% w/w）相关。糖脂被鉴定为单半乳糖基二酰甘油。在雄配子的附睾转运过程中，各种膜脂质的脂肪酸谱发生了显著变化。成熟精子膜中胆固醇/磷脂和饱和/不饱和脂肪酸比值大幅增加。成熟精子膜脂质谱的改变导致其流动性变化，这在决定生物膜的结构和功能中起重要作用。