Hitchcock-DeGregori S E, Sampath P, Pollard T D
Department of Anatomy, UMDNJ-Robert Wood Johnson Medical School, Piscataway 08854.
Biochemistry. 1988 Dec 27;27(26):9182-5. doi: 10.1021/bi00426a016.
Tropomyosin inhibition of the rate of spontaneous polymerization of actin is associated with binding of tropomyosin to actin filaments. Rate constants determined by using a direct electron microscopic assay of elongation showed that alpha alpha- and alpha beta-tropomyosin have a small or no effect on the rate of elongation at either end of the filaments. The most likely explanation for the inhibition of the rate of polymerization of actin in bulk samples is that tropomyosin reduces the number of filament ends by mechanical stabilization of the filaments.
原肌球蛋白对肌动蛋白自发聚合速率的抑制与原肌球蛋白与肌动蛋白丝的结合有关。通过直接电子显微镜伸长测定法确定的速率常数表明，αα-和αβ-原肌球蛋白对丝两端的伸长速率影响很小或没有影响。对大量样品中肌动蛋白聚合速率受到抑制的最可能解释是，原肌球蛋白通过对丝的机械稳定作用减少了丝端的数量。
