ISSN:
1040-452X
Keywords:
Sperm (bull, rabbit)
;
Plasma membranes
;
Acrosomal membranes
;
Phosphatidylinositol specific phospholipase C
;
Phosphatidyl choline specific phospholipase C
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Acrosomal reaction is an essential prerequisite to fertilization. The changes in lipid composition of sperm membranes cause fusion of the plasma and outer acrosomal membranes that results in the exocytosis of acrosomal contents. We report that both bull and rabbit spermatozoa contain a phosphatidylcholine-specific phospholipase C (PC-PLC) that hydrolyzes L-α-dipalmitoyl-(choline-methyl-14C-153.0 Ci/mmol and a phosphatidyl-inositol-specific phospholipase C (Pl-PLC)) that hydrolyzes L-α-(Myo)-lnositol-2-3H (N)-5.2 Ci mmol. Pl-PLC from bull sperm acrosome has been purified 568 × fold with a specific activity 6.25 ± 0.6 nmol/min/mg protein, km 0.004 mM, and Vmax 12 nmol/min/mg protein. Both enzymes had optimum at pH 7.5. The activity of PC-PLC remained unaffected by varying concentrations of Ca2+, whereas Pl-PLC activity was significantly increased. The bulk of Pl-PLC was found to be associated with inner acrosomal membrane of bull and rabbit sperm, while PC-PLC was found in the outer acrosomal membranes in the bull sperm and the plasma membrane of the rabbit sperm. Both enzymes are compartmentalized in sperm cell. © 1992 Wiley-Liss, Inc.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrd.1080330308
Permalink
