Szöör A, Kalamkarova M, Rapcsák M, Kofman E, Aleynikova K, Richter P
Acta Physiol Hung. 1983;61(1-2):69-75.
The conformation change of light meromyosin influences the myosin and actin interaction, the myosin ATPase activity [22]. Starting from these data the specificity of the phenomenon has been investigated. The effect of LMM1, LMM- and LMM1-antibodies was studied on the isometric tension and relaxation of glycerol extracted muscle fibres. LMM1 was found to relax the fibres isometrically contracted by ATP-Ca2+; anti-LMM and anti-LMM1 markedly accelerated the development of isometric tension and inhibited the relaxation of ATP contracted glycerinated muscle fibres; in the presence of anti-LMM the ATPase rate of glycerinated myofibrils was slightly augmented. These results seem to indicate that LMM1 governs the actin binding site function of myosin and controls its affinity to actin. It is supposed that the reaction of myofibrils with specific LMM antibodies induced a transconformation in the myosin head increasing the affinity to actin of myosin.
轻酶解肌球蛋白的构象变化会影响肌球蛋白与肌动蛋白的相互作用以及肌球蛋白ATP酶活性[22]。基于这些数据，对该现象的特异性进行了研究。研究了LMM1、LMM和LMM1抗体对甘油提取的肌纤维等长张力和舒张的影响。发现LMM1可使由ATP-Ca2+引起等长收缩的纤维舒张；抗LMM和抗LMM1显著加速等长张力的发展，并抑制ATP收缩的甘油化肌纤维的舒张；在抗LMM存在的情况下，甘油化肌原纤维的ATP酶活性略有增强。这些结果似乎表明，LMM1控制着肌球蛋白的肌动蛋白结合位点功能，并控制其对肌动蛋白的亲和力。据推测，肌原纤维与特异性LMM抗体的反应会诱导肌球蛋白头部发生转构象，从而增加肌球蛋白对肌动蛋白的亲和力。
