Gdańsk University Biological Station, Department of Molecular Evolution, 80-308 Gdańsk, Poland.
Comp Biochem Physiol B Biochem Mol Biol. 2013 Mar;164(3):216-20. doi: 10.1016/j.cbpb.2013.01.001. Epub 2013 Jan 11.
Herring spermatozoa exhibit higher activity of malic enzyme (ME) than Atlantic salmon (Salmo salar), brown trout (Salmo trutta), carp (Cyprinus carpio) and African catfish (Clarias gariepinus) spermatozoa. Two molecular forms of ME are present in herring spermatozoa: an NAD-preferring malic enzyme with very high activity and an NADP-specific malic enzyme with much lower activity (ratio about 33:1). NAD-preferring ME was purified by chromatography on DEAE-Sepharose, Red Agarose and Sephadex G-200 to a specific activity of 36 μmol/min/mg protein and NADP-specific ME on DEAE-Sepharose and 2'5'-ADP Sepharose. The molecular mass for NAD-preferring and NADP-specific ME determined by SDS-PAGE was equal to 61 and 64 kDa, respectively. High activity of ME suggests adaptation of herring spermatozoa to metabolism at high oxygen tension for herring spawn.
鲱鱼精子的苹果酸酶（ME）活性高于大西洋鲑（Salmo salar）、褐鳟（Salmo trutta）、鲤鱼（Cyprinus carpio）和非洲鲶鱼（Clarias gariepinus）精子。鲱鱼精子中存在两种苹果酸酶的分子形式：一种是对 NAD 有很高亲和力的苹果酸酶，具有非常高的活性，另一种是对 NADP 有特异性的苹果酸酶，活性要低得多（比值约为 33:1）。对 NAD 有高亲和力的 ME 通过 DEAE-琼脂糖、红琼脂糖和 Sephadex G-200 层析进行纯化，比活达到 36μmol/min/mg 蛋白，NADP-特异性 ME 通过 DEAE-琼脂糖和 2'5'-ADP 琼脂糖进行纯化。SDS-PAGE 测定 NAD 有高亲和力的 ME 和 NADP-特异性 ME 的分子量分别为 61 和 64 kDa。ME 的高活性表明鲱鱼精子适应了鲱鱼产卵时高氧张力下的代谢。
