Characteristics of acid phosphatase from rainbow trout (Oncorhynchus mykiss) spermatozoa

Abstract

Acid phosphatase (AcP) is a commonly observed enzyme in animal semen. In this study, AcP in rainbow trout (Oncorhynchus mykiss) spermatozoa was partly purified and characterized. Extraction in 0.85% NaCl with 0.1% Triton X-100 enabled obtaining 95% of total AcP activity observed in sperm supernatant. Kinetic characteristics were described for the enzyme from sperm extract and for the partly purified enzyme following gel filtration. The optimum pH was 5.8 for unpurified and 5.6 for partly purified enzyme. The affinity of the substrates measured in the sperm extract for p-nitrophenylphosphate dissodium salt and b-glycerophosphate was Km = 1.5 × 10-3M and Km = 1.9 × 10^-3M, respectively. The Km for partly purified enzyme was similar at 1.67 × 10^-3M measured with p-nitrophenylphosphate dissodium salt. L-tartaric acid and ammonium molybdate were the inhibitors of AcP for unpurified and partly purified enzyme. SDS-PAGE electrophoresis revealed that AcP from rainbow trout had a molecular weight of about 41 kDa.

CORRESPONDING AUTHOR:

Beata Sarosiek, Polska Akademia Nauk, Instytut Rozrodu Zwierząt i Badań Żywności, Zakład Andrologii Molekularnej, ul. Bydgoska 1/8, 10-243 Olsztyn, Tel./Fax: +48 (89) 5357421;
e-mail: pirosia@pan.olsztyn.pl