[Tropomyosins in human muscular and non-muscular tissue]

Tropomyosin was isolated from human heart and skeletal muscles, liver, kidney and lung tissues. The subunit composition and relative molecular mass of tropomyosins were studied using polyacrylamide gel electrophoresis in presence of sodium dodecylsulfate. The tropomyosin from heart muscle migrated as a homogenous zone and had a relative molecular mass of 34,000 daltons. The tropomyosin from skeletal muscles was separated into two zones containing polypeptides of 47,200 and 35,000 daltons. Proteins from nonmuscular tissues constituted two fractions with relative molecular mass of 35,000 and 29,000 daltons. alpha-Chains of tropomyosins in various human tissues were similar to each other as shown using immunodiffusion procedure.