Turkey acrosin. I. Isolation, purification, and partial characterization.

Acrosin was extracted from turkey spermatozoa by use of urea together with sonication and freezing, and purified approximately 18-fold by sequential use of chromatofocusing and affinity chromatography. The use of chromatofocusing for the initial purification step proved to be superior to preparative isoelectric focusing. Similar to acrosin from many mammalian species, turkey acrosin was found to be a glycoprotein possessing characteristics of serine proteases. Polyacrylamide gel electrophoresis (PAGE) of the enzyme indicated the presence of two isozymes. Sodium-dodecyl sulfate PAGE under reducing conditions revealed three subunits with approximate molecular weights of 11,700, 13,900, and 15,900.