Klotz C, Aumont M C, Berson G, Leger J J, Preteseille M, Swynghedauw B
Recent Adv Stud Cardiac Struct Metab. 1975;5:263-71.
A low myofibrillar ATPase seems to be established definitely in several experimental models of chronic heart hypertrophy as well as in humans, but the biochemical pathogenesis of this defect is still unclear. Three different preparations of myosin were studied. Their purity was estimated by measuring MgATPase or by polyacrylamide gel electrophoresis. The first preparation was highly contaminated by actin and tropomyosin; the second was rather pure, and the third (chromatography on DEAE-Sephadex) was pure but slightly denaturated. Heart myosin CaATPase (ionic strength 0.6 or 0.06) was decreased in chronic aortic insufficiency in the rabbits (CAI) when all three preparations were tested. Two (molecular weight 18,000 and 26,000), sometimes three light subunits were found in heart myosin. Their charge and molecular weight are normal in CAI. The third subunit (molecular weight 15,500) was found in control as well as in CAI. Search for an inhibitor was unsuccessful since the two myosin ATPases are additive. The nucleoprotein peak separated from myosin during chromatography was identical in control and CAI. Therefore, myosin seems to be abnormal in CAI.
在几种慢性心脏肥大的实验模型以及人类中，低肌原纤维ATP酶似乎已明确确立，但这种缺陷的生化发病机制仍不清楚。研究了三种不同的肌球蛋白制剂。通过测量MgATP酶或聚丙烯酰胺凝胶电泳来估计它们的纯度。第一种制剂被肌动蛋白和原肌球蛋白高度污染；第二种相当纯，第三种（在DEAE-葡聚糖凝胶上进行色谱分离）是纯的，但略有变性。当测试所有三种制剂时，兔慢性主动脉瓣关闭不全（CAI）时心脏肌球蛋白CaATP酶（离子强度0.6或0.06）降低。在心脏肌球蛋白中发现了两个（分子量分别为18,000和26,000），有时是三个轻亚基。它们的电荷和分子量在CAI中是正常的。在对照组和CAI中均发现了第三个亚基（分子量15,500）。由于两种肌球蛋白ATP酶具有加和性，寻找抑制剂的尝试未成功。在色谱分离过程中与肌球蛋白分离的核蛋白峰在对照组和CAI中是相同的。因此，CAI中的肌球蛋白似乎是异常的。
