심장근과 골격근의 Malate dehydrogenase(MDH)에 관한 연구

Abstract

본 연구는 산화적 대사계를 형성하고 있는 심장근세포와 골격근의 red muscle에 대하여 TCA cycle의 key enzyme의 하나인 MDH를 분리하여 그 생화학적 성질을 비교한 것이다. MDH의 활성에 있어서는 골격근의 MDH활성을 1.0으로 하였을 때 심장근의 MDH 활성은 2.8로 심장근이 산화능력이 큰 조직임을 나타내었고, 심장근과 골격근에 있어서 MDH의 분포는 cMDH가 mMDH보다 더 높은 함량을 나타내었으며, cMDH와 mMDH의 비활성은 심장근과 골격근 사이에 차이를 나타내었다. 열안정성에 있어서는 심장근의 MDH가 골격근의 MDH보다 높은 것으로 나왔으며, 한편 cMDH의 열안정성은 mMDH의 열안정성보다 높았다. 기질친화도에 있어서는 mMDH의 경우 심장근의 골격근보다 높은 기질친화도를 나타내 근육에 따른 세포내에서의 MDH의 기능에 차이가 있을 수 있음을 나타내었다.

Malate dehydrogenase was extracted from cardiac muscle and skeletal muscle, and biochemical characteristics were compared each other. Malate dehydrogenase activity in cardiac muscle was 2.8 times as high as that of skeletqal muscle. In cardiac muscle and skeletal muscle, the content of cytoplasmic malate dehydrogenase was higher than that of mitochondrial malate dehydrogenase. Malate dehydrogenase of cardiac muscle was more thermostable than that of skeletal muscle. Thermostability of cytoplasmic malate dehydrogenase was higher than that of mitochondrial malate dehydrogenase. The Km value of mitochondrial malate dehydrogenase from cardiac muscle showed higher than that of skeletal muscle.

Malate dehydrogenase was extracted from cardiac muscle and skeletal muscle, and biochemical characteristics were compared each other. Malate dehydrogenase activity in cardiac muscle was 2.8 times as high as that of skeletqal muscle. In cardiac muscle and skeletal muscle, the content of cytoplasmic malate dehydrogenase was higher than that of mitochondrial malate dehydrogenase. Malate dehydrogenase of cardiac muscle was more thermostable than that of skeletal muscle. Thermostability of cytoplasmic malate dehydrogenase was higher than that of mitochondrial malate dehydrogenase. The Km value of mitochondrial malate dehydrogenase from cardiac muscle showed higher than that of skeletal muscle.