Diffusible highly glycosylated protein from Bufo arenarum egg-jelly coat: biological activity.
L-HGP is a highly glycosylated protein from Bufo arenarum egg-jelly coat that diffuses into the surrounding medium when the strings of oocytes are incubated in saline solutions. L-HGP was purified from egg water and the estimated percentage of L-HGP/total protein in egg water was estimated in 30%. In the present study we examine, by indirect immunofluorescence, the effect of L-HGP on acrosome status of homologous spermatozoa. A high percentage (77%) of sperm lost the acrosome when incubated in 10% Ringer solution buffered with 10 mM Tris-HCl, pH 7.6, during 60 min, a condition that resembles egg-jelly osmolarity. The addition of purified L-HGP to the incubation medium prevents acrosome breakdown. The acrosome integrity is maintained for at least 1 hr. This effect is specific for L-HGP at concentration ranging from 0.01 to 0.1 mg/ml since neither BSA nor fetuin seems to have similar activity at similar concentrations. The same effect was observed when spermatozoa were incubated in egg water. Preliminary results suggest that L-HGP binds to B. arenarum spermatozoan membranes.
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IBR (CONICET), Area Biología, Departatmento de Ciencias Biológicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, UNR, Rosario, Argentina.
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D000177:Acrosome / Q000502:physiology*; D000818:Animals; D002022:Bufo arenarum; D004058:Diffusion; D004527:Egg Proteins / Q000302:isolation & purification / Q000378:metabolism*; D005260:Female; D005298:Fertility / Q000502:physiology; D006023:Glycoproteins / Q000302:isolation & purification / Q000378:metabolism*; D008297:Male; D010063:Ovum / Q000378:metabolism / Q000502:physiology; D013094:Spermatozoa / Q000378:metabolism / Q000502:physiology*
D004527:Egg Proteins; D006023:Glycoproteins