Gailly P, Lejeune T, Capony J P, Gillis J M
Département de Physiologie, Université Catholique de Louvain, Bruxelles, Belgium.
J Muscle Res Cell Motil. 1990 Aug;11(4):293-301. doi: 10.1007/BF01766667.
Brevin is a protein which regulates the actin gel-sol transformation: it severs F-actin filaments into shorter ones. This action is Ca-dependent and is prevented by tropomyosin. We tested the effect of brevin on isometric contractions of skinned smooth muscle (taenia coli) and noted a dramatic loss of tension that possibly reflects some F-actin fragmentation. This effect is tentatively attributed to a partial loss of tropomyosin in the skinning procedure. We also studied the effect of brevin on unloaded shortenings of skinned preparations: thin bundles and enzymatically dissociated cells. We observed a marked increase of the velocity of shortening in the presence of brevin. This effect cannot be attributed to an increased ATPase activity as the latter is slightly reduced in the presence of brevin. We interpret this result as reflecting a decrease in internal resistance to movement, possibly by solation of an actin-filamin domain.
布雷文是一种调节肌动蛋白凝胶-溶胶转变的蛋白质：它将F-肌动蛋白丝切断成较短的丝。这种作用依赖于钙，并受到原肌球蛋白的抑制。我们测试了布雷文对去皮肤平滑肌（结肠带）等长收缩的影响，发现张力急剧下降，这可能反映了一些F-肌动蛋白的片段化。这种效应暂时归因于去皮肤过程中原肌球蛋白的部分丧失。我们还研究了布雷文对去皮肤制剂（细束和酶解细胞）无负荷缩短的影响。我们观察到在布雷文存在的情况下缩短速度显著增加。这种效应不能归因于ATP酶活性的增加，因为在布雷文存在的情况下后者略有降低。我们将这一结果解释为反映了内部运动阻力的降低，可能是通过肌动蛋白-细丝蛋白结构域的溶胶化实现的。
