title: Interactions of boar acrosin with detergents.
abstract: The activity of boar acrosin was found to be stimulated up to 260% by non-ionic detergents if present in concentrations above their critical micelle concentration. In addition, the stability of acrosin was remarkably enhanced in the presence of 0.1% (w/v) detergents. Triton X-100 was found to reduce the affinity of acrosin to the synthetic inhibitor 6-amidino-2(4'-methoxyphenyl)indole by the factor 2.9 when Ki values were measured in buffer solutions in the presence (0.1%, w/v) and absence of Triton X-100. Phospholipids did nearly completely abolish the acrosin activity, this effect being reversibly by addition of 0.1% (w/v) Triton X-100. These results are interpreted in terms of hydrophobic binding sites exposed on the surface of the acrosin molecule. Hence, for the first time data are presented characterizing acrosin as a membrane-associated protein.
mesh_terms: D000176:Acrosin / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D003902:Detergents / Q000494:pharmacology*; D010450:Endopeptidases / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D010743:Phospholipids / Q000494:pharmacology; D011092:Polyethylene Glycols / Q000494:pharmacology; D011136:Polysorbates / Q000494:pharmacology; D012661:Semen / Q000201:enzymology*; D013501:Surface-Active Agents / Q000494:pharmacology*
chemical_list: D003902:Detergents; D008565:Membrane Proteins; D010743:Phospholipids; D011136:Polysorbates; D013501:Surface-Active Agents; D011092:Polyethylene Glycols; D010450:Endopeptidases; D000176:Acrosin