Development of myosin isoform function in single ventricular myocytesHeart

大鼠心室通常含有a-rnyosin重链异构体，当心室过载时，它们被n-重链异构体所取代，从而导致张力成本降低。而人心室仅由β-肌球蛋白重链异构体组成，在心室负荷过重的情况下，其异构体组成不会发生变化。为了进一步了解人类心室对过载的适应模式，我们研究了改变肌凝蛋白轻链亚型对心室肌凝蛋白运动功能的影响。我们发现肌凝蛋白轻链异构体实际上影响每个心室肌凝蛋白分子施加的力的大小。

Rat ventricle normally contains a-rnyosin heavy chain isoforms, and if exposed to ventricular overload, they are replaced by n-heavy chain isoforms, to result in a decrease in tension cost. Human ventricle, on the other hand, only consists of β-myosin heavy chain isoforms, and the isoform composition does not change under the condition of ventricular overload.To given information about the mode of adaptation of human ventricle to overload, we studied the effect of changing the myosin light chain isoforms on the motor function of ventricular myosin. We found that myosin light chain isoforms actually affects the magnitude of force exerted by each ventricular myosin molecule.