Phosphatidylcholine synthesis in human spermatozoa.
To clarify the mechanism of phospholipid synthesis in spermatozoa, fresh human spermatozoa were incubated with labeled fatty acids and 1-acyl-lysophosphatidyl choline (LPC) in the presence or absence of coenzyme A (CoASH). Both docosahexaenoic acid and palmitic acid were incorporated into phosphatidylcholine; however, this reaction was absolutely dependent upon the presence of CoASH in the incubation medium. The rate of incorporation of docosahexaenoic acid was 2.7-fold higher than that of palmitic acid, but more palmitic acid was incorporated into phosphatidylcholine in the absence of LPC. These data provide direct evidence for acyl transferase activity in human spermatozoa and may furnish a mechanism for phospholipid remodeling in sperm membranes. The different incorporation rates of these fatty acids into phosphatidylcholine may be due to the kinetics of the activation step, long chain fatty acid:CoASH ligase (AMP), or the substrate specificity of the acyl transferase.
Jones
R E
RE
Department of Medicine, Madigan Army Medical Center, Tacoma, Washington 98431-5000.
Plymate
S R
SR
D003065:Coenzyme A / Q000494:pharmacology; D004281:Docosahexaenoic Acids / Q000378:metabolism; D006801:Humans; D008244:Lysophosphatidylcholines / Q000378:metabolism; D008297:Male; D010169:Palmitic Acids / Q000378:metabolism; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D013094:Spermatozoa / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
D008244:Lysophosphatidylcholines; D010169:Palmitic Acids; D010713:Phosphatidylcholines; D004281:Docosahexaenoic Acids; D003065:Coenzyme A