Hoffmann U, Axmann C, Grisk A
Biomed Biochim Acta. 1986;45(8):985-996.
Distinct myosin isoforms were identified from the ventricles and atria of foetal, normal and hypertrophied human hearts. Ventricle and atrium myosins cannot be differentiated by their sedimentation behaviour in the analytical ultracentrifuge, they vary, however, with regard to the Ca2+-dependent ATPase and also the activation parameters in measurements of the enzyme activity in dependence on temperature. In agreement with other authors we observed a foetal light chain in the ventricular tissue of the latter half of gestation, when myosin was characterized by SDS-polyacrylamide gel electrophoresis and isoelectric focusing. Using pyrophosphate gel electrophoresis an additional foetal isomyosin was observed besides the typical ventricular myosin HV-3, which migrates faster. Two distinct myosin isoforms designated as HA-3 and HA-1 occur in the atrium of the normal human heart. It was found that besides their own isoenzymes normal atria also contain ventricular isomyosin, whose relative proportion is markedly increased in the hypertrophic atrium. In contrast, we usually observed only one isoenzyme in the normal ventricle. Moreover, in case of myocardial infarction a dramatic transformation of myosin heavy chain composition with a shift to an atrial myosin type took place in the ventricle.
在胎儿、正常及肥厚型人类心脏的心室和心房中鉴定出了不同的肌球蛋白亚型。心室和心房肌球蛋白在分析超速离心机中的沉降行为无法区分它们，但在依赖于温度的酶活性测量中，它们在钙依赖性ATP酶以及激活参数方面存在差异。与其他作者一致，当通过SDS-聚丙烯酰胺凝胶电泳和等电聚焦对肌球蛋白进行表征时，我们在妊娠后半期的心室组织中观察到了胎儿轻链。使用焦磷酸凝胶电泳，除了迁移速度更快的典型心室肌球蛋白HV-3外，还观察到了一种额外的胎儿异肌球蛋白。正常人类心脏的心房中存在两种不同的肌球蛋白亚型，分别命名为HA-3和HA-1。研究发现，除了自身的同工酶外，正常心房还含有心室异肌球蛋白，其相对比例在肥厚型心房中显著增加。相比之下，我们通常在正常心室中仅观察到一种同工酶。此外，在心肌梗死的情况下，心室中的肌球蛋白重链组成发生了显著转变，向心房肌球蛋白类型转变。
