N-acetyl beta-D-glucosaminidase is not attached to human sperm membranes through the glycosylphosphatidyl inositol (GPI)-anchor.
OBJECTIVE
The mode of anchorage of N-acetyl beta-D-glucosaminidase (NAGA) on human ejaculated sperm was investigated.


METHODS
Sperm plasma membrane was prepared by discontinuous sucrose gradient centrifugation from human sperm. NAGA was solubilized from these membranes by two detergents: octyl-glycoside and triton X-100. In separate studies, the release of the enzyme from the sperm membrane preparation by phosphatidylinositol specific phospholipase C (PI-PLC) was also examined.


RESULTS
NAGA activity was detected on sperm membranes isolated from human ejaculates. The pattern of the enzyme solubilization by detergents indicated that the enzyme was an integral protein of sperm membrane. NAGA was not released from the sperm membranes by PI-PLC treatment.


CONCLUSIONS
The evidence presented strongly suggests that human sperm membrane bound NAGA is not attached via the GPI anchor.
Hutchinson
T
T
Department of Biosciences and Biotechnology, Indian Institute of Technology, Roorkee, Uttaranchal.
Dwivedi
K
K
Rastogi
A
A
Prasad
R
R
Pereira
B M J
BM
D000118:Acetylglucosaminidase / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000328:Adult; D000469:Alkaline Phosphatase / Q000378:metabolism; D003902:Detergents; D017261:Glycosylphosphatidylinositols / Q000378:metabolism*; D006801:Humans; D008297:Male; D008861:Microsomes / Q000201:enzymology; D008875:Middle Aged; D017830:Octoxynol; D013094:Spermatozoa / Q000201:enzymology*
D003902:Detergents; D017261:Glycosylphosphatidylinositols; D000255:Adenosine Triphosphate; D017830:Octoxynol; D000469:Alkaline Phosphatase; D000118:Acetylglucosaminidase