쏘가리 젖산탈수소효소(EC 1.1.1.27, lactate dehydrogenase, LDH) A4 동위효소를 affinity chromatography 및 ultrafiltration으로 정제하였다. 정제된 LDH A4 동위효소의 분자량은 140.4 kDa이었고 등전점(pI)은 7.0이었다. 효소반응의 최적 pH는 7.5로 나타났다. 피루브산을 기질로 하였을 때 LDH A4 동위효소의 KmPYR값은 4.86×10-5 M, Vmax값은 13.31 mM/min로 나타났다. LDH A4 동위효소의 역학실험은 쏘가리가 온수성어류라는 점을 보여주었고 정제된 LDH A4 동위효소에 대한 항체는 변온 척추동물의 대사생리학적 특성을 연구하거나 여러 가지 병증의 진단에 유용하게 사용될 수 있을 것이다.The lactate dehydrogenase (EC 1.1.1.27, LDH) A4 isozyme in skeletal muscle of mandrin fish (Siniperca scherzeri) was successfully purified by affinity chromatography and ultrafiltration. The molecular weight of the purified LDH A4 isozyme was 140.4 kDa and its isoelectric point (pI) was 7.0. Optimal pH for enzymatic reaction was 7.5. KmPYR and Vmax value of the purified LDH A4 isozyme were 4.86?0-5 M and 13.31 mM/min using pyruvate as a substrate, respectively. These kinetic properties of the purified LDH A4 isozyme supported the fact that the mandrin fish was a warm-adapted species. The antibody against the purified LDH A4 isozyme may be used in the metabolic physiological studies of ectothermic vertebrates and in the diagnosis of several human diseases.