Properties of acid beta-galactosidase from fowl spermatozoa.

1. Two forms, I and II, of beta-galactosidase [EC 3.2.1.23] from fowl spermatozoa were separated by Blue-Sepharose CL-6B chromatography. 2. The two forms of the enzyme yielded different pI values (4.1 and 4.7 for form I and 5.3 for form II). 3. Their gel filtration patterns were also different: form I resolved into two peaks with Mr about 65,000 and 80,000, whereas form II resolved into a single peak with an Mr of about 65,000. 4. Both forms had similar optimum pH, pH stability, thermal stability and Km values. 5. Differences between the characteristics of beta-galactosidase forms from spermatozoa and from seminal plasma suggest that the beta-galactosidases investigated in this study are spermatozoa-specific.