横纹肌收缩
中文名称
通路描述
横纹肌收缩是横纹肌组织中产生力的过程，导致肌肉几何形状改变，简而言之，是在肌腱上施加增加的力。力生成涉及由肌动蛋白/肌球蛋白复合物活性执行的化机械能转换步骤，通过 ATP 水解产生力。横纹肌是由肌原纤维组成的肌肉类型，其中包含称为肌节的重叠单元，肌原纤维平行排列于细胞轴上，在光显微镜水平下产生横纹或斜纹。横纹肌收缩在此表示为钙离子与肌钙蛋白复合物的结合，暴露肌动蛋白的活性位点。一旦肌动蛋白的活性位点暴露，与 ADP 结合的肌球蛋白复合物就可以结合肌动蛋白，肌球蛋白头部可以旋转，拉动细肌丝和粗肌丝相互 past。当肌球蛋白头部旋转时，ADP 被排出，可以结合新鲜 ATP，ATP 水解产生的能量通过重置肌球蛋白头部被引导为动能。通过这种循环的重复，包含细丝和粗丝的肌节有效地缩短，形成肌肉收缩的基础。
英文描述
Striated Muscle Contraction Striated muscle contraction is a process whereby force is generated within striated muscle tissue, resulting in a change in muscle geometry, or in short, increased force being exerted on the tendons. Force generation involves a chemo-mechanical energy conversion step that is carried out by the actin/myosin complex activity, which generates force through ATP hydrolysis. Striated muscle is a type of muscle composed of myofibrils, containing repeating units called sarcomeres, in which the contractile myofibrils are arranged in parallel to the axis of the cell, resulting in transverse or oblique striations observable at the level of the light microscope.
Here striated muscle contraction is represented on the basis of calcium binding to the troponin complex, which exposes the active sites of actin. Once the active sites of actin are exposed, the myosin complex bound to ADP can bind actin and the myosin head can pivot, pulling the thin actin and thick myosin filaments past one another. Once the myosin head pivots, ADP is ejected, a fresh ATP can be bound and the energy from the hydrolysis of ATP to ADP is channeled into kinetic energy by resetting the myosin head. With repeated rounds of this cycle the sarcomere containing the thin and thick filaments effectively shortens, forming the basis of muscle contraction.
Here striated muscle contraction is represented on the basis of calcium binding to the troponin complex, which exposes the active sites of actin. Once the active sites of actin are exposed, the myosin complex bound to ADP can bind actin and the myosin head can pivot, pulling the thin actin and thick myosin filaments past one another. Once the myosin head pivots, ADP is ejected, a fresh ATP can be bound and the energy from the hydrolysis of ATP to ADP is channeled into kinetic energy by resetting the myosin head. With repeated rounds of this cycle the sarcomere containing the thin and thick filaments effectively shortens, forming the basis of muscle contraction.
所含基因
36 个基因