Synthetic peptides of actin-tropomyosin binding region of troponin I and heat shock protein 20 modulate the relaxation process of skinned preparations of taenia caeci from guinea pig.
Synthetic peptides of actin-tropomyosin binding region of troponin I and heat shock protein 20 modulate the relaxation process of skinned preparations of taenia caeci from guinea pig.
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肌钙蛋白 I 的肌动蛋白-原肌球蛋白结合区和热休克蛋白 20 的合成肽调节豚鼠盲肠带皮制剂的松弛过程。
DOI：
10.2170/jjphysiol.rp002605
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Masaru Watanabe
中科院分区：
文献类型：
--
作者：
Yasumasa Yoshino;Wataru Sakurai;S. Morimoto;Masaru Watanabe
为了探索在活体平滑肌收缩中，跨桥循环的薄顺时针连接调节的可能作用，我们研究了TnIp和HSP 20 p的作用，HSP 20 p是一种源自兔心肌肌钙蛋白I的肌动蛋白原肌球蛋白结合区的合成肽（残基136-147; GKFKRPTLRRVR）和人热休克蛋白20的（残基110-121; GFVAREFHRRYR）对豚鼠盲肠带的带皮（细胞膜化）制剂松弛的影响。由肌动蛋白-肌球蛋白相互作用引起的去皮制剂的主动应力在Ca（2+）去除后迅速衰减（松弛）。TnIP加速了松弛的初始快速相，并减慢了随后的缓慢相。而HSP 20 p仅减缓了整个舒张过程。应力的双指数衰减可以解释为一部分快速分离的横桥没有被Ca（2+）去除而迅速解离，而是转移到非常缓慢解离的闩桥上。结果表明：（i）TnIp和HSP 20 p促进了快分离横桥向慢分离（闩锁）桥的转移;（ii）TnIp促进了快分离横桥和闩锁桥的解离，而HSP 20 p减慢了快分离横桥的解离。由于TnIP和HSP 20 p被认为与肌动蛋白和原肌球蛋白结合，但不与肌球蛋白结合，因此我们得出结论，这些肽通过细丝依赖性机制调节平滑肌中闩桥的形成和/或变形。平滑肌细胞的应力维持和松弛可能是由这种依赖于细丝的调节机制所控制的。
To explore the possible role of the thin filament-linked regulation of cross-bridge cycling in living smooth muscle contraction, we studied the effects of TnIp and HSP20p, a synthetic peptide originating from an actin tropomyosin binding region of rabbit cardiac troponin I (residues 136-147; GKFKRPTLRRVR), and that of human heat shock protein 20 (residues 110-121; GFVAREFHRRYR) on the relaxation of skinned (cell membrane ilized) preparations from guinea pig taenia caeci. An active stress of the skinned preparations, resulting from actin-myosin interaction, rapidly decayed following Ca(2+) removal (relaxation). TnIp accelerated the initial rapid phase and slowed the following slow phase of the relaxation. On the other hand, HSP20p only slowed the whole process of the relaxation. The relaxation time courses were well fitted in a double exponential manner, and the double exponential decay of the stress could be explained as a portion of fast-detaching cross bridges not to dissociate rapidly by Ca(2+) removal, but to transfer to latch bridges dissociating very slowly. Our present results suggested that (i) TnIp and HSP20p accelerated transferring from fast-detaching cross bridges to slow-detaching (latch) bridges, and (ii) TnIp accelerated dissociation of the fast-detaching cross bridges and the latch bridges, while HSP20p slowed dissociation the fast-detaching cross bridges. Since TnIp and HSP20p are thought to bind to actin and tropomyosin, but not to myosin, we concluded that through thin-filament-dependent mechanisms these peptides regulated the formation and/or deformation of latch bridges in smooth muscle. The thin-filament-dependent regulation might physiologically control the stress maintenance and relaxation in smooth muscle cells.
平滑肌中的共价跨桥调节。
影响因子：
5.2
作者：
McDaniel,NL;Rembold,CM;Murphy,RA
通讯作者：
Murphy,RA