Energy transduction in muscle contraction : Study with single thick filaments

肌肉收缩中的能量传导：单根粗肌丝的研究

基本信息

批准号：
04640651
负责人：
ISHII Naokata
金额：
$ 1.41万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04640651/
关键词：
Muscle contraction In vitro motility assay Native thick filaments Actin calbles Molluscan smooth muscle Centrifugal force Force-velocity relation Crossbridge mechanism アクチンフィラメント

项目摘要

To obtain information about the kinetics of force-generating processes in the actomyosin crossbridges which retain naturally ordered arrangement, we studied the force-velocity relations in sliding movements of native thick filaments along F-actin cables.Native thick filaments (length, up to 30 mum) were isolated from the anterior byssus retractor muscle (ABRM) of Mytilus edulis and attached to polystirene microbeads (diameter, 4mum) coated previously with poly-L-lysine. The beads were placed on F-actin cables of perfused Chara internodal cells, which was then mounted on a rotating stage of a centrifuge microscope, and the velocities of steady state, sliding movements of the beads in the presence of ATP(3mM) were measured under both positive(opposite to the direction of sliding)and negative(same as that of sliding)centrifugal loads(up to 30 pN). Under the positive load, the force-velocity relation was well described, in its most part (with the exception of a small "hump" above 0.8P0), by Hill equation and appeared markedly similar to that for frog single muscle fibers. Under the negative load, the sliding velocity initially increased with force beyond the maximal unloaded velocity (V0), then appeared to reach a steady level at 2-3V0 until the beads were eventually detached from actin cables. The results suggest that the minimal unit responsible for the classical force-velocity relations is several tens or hundreds of crossbridges, and their ordered arrangement along thick filaments plays an important role in determining the mechanical properties of muscle contraction.

为了获取有关保留自然有序排列的肌动球蛋白杂交桥梁中力动力学的信息，我们研究了沿F-肌动蛋白电缆的本机厚细丝的滑动运动中的力 - 速度关系。具有较厚的厚细丝（长度，长达30 mum）与缩减的肌肉（与缩减的ummus anderors and cretirers contracter and intrestor contracter and intrestire contracters contracters contracters contracter and intrys contracterss contracte and intram and intram contrame and intramss cormire contram and intrif）先前用聚-l赖氨酸涂层的微粒（直径为4MUM）。将珠子放在灌注的Chara节节节结肠细胞的F-肌动蛋白电缆上，然后将其安装在离心机显微镜的旋转阶段，并在稳态的速度，在存在ATP（3mm）的情况下的珠子运动的速度，在两者均方（与滑动的方向相反）和平面sellse sellistife（相同）下（相反）sellistififfifugifuguguguguguguguguguguguguguguguguguguguguguguguguguguguguguguguguguguguggug for。在正载载荷下，在大部分地区（大部分的“驼峰”高于0.8p0）的力量相关性很好地描述了，山山等式与青蛙单肌纤维显着相似。在负载荷下，滑动速度最初会随着最大卸载速度（V0）的力而增加，然后似乎在2-3v0处达到稳定水平，直到珠最终从肌动蛋白电缆脱离为止。结果表明，负责经典力量关系关系的最小单元是几十或数百个越野，它们沿厚细丝的有序排列在确定肌肉收缩的机械性能中起着重要作用。