3 major components of troponin were obtained in a highly purified state on fractionation of troponin on DEAE Sephadex A 50 in the presence of urea, EDTA with KCl gradient. The components were characterized in respect to electrophoretic mobility on polyacrylamide gel in the presence and absence of Ca2+ and in the presence of sodium dodecyl sulphate. 2 components: 23500 daltons protein (TN I) and 18300 daltons protein (TN-C) are sufficient to confer Ca2+ sensitivity to actomyosin. TN-C is the only one which has a high affinity for Ca2+. The third component of mol. wt. 40200 daltons (TN-B) interacts with tropomyosin and F-actin. TN-C is distinguished by a high phenylalanine content and extremely high negative charge (isoelectric point at pH 3.8). All components differ in respect to thiol group content. The components of mol. wt. 30000 and 13000 daltons, usually present in troponin preparations, are the products of proteolytic degradation of TN-B and TN-I, respectively. For minimizing this degradation the procedure of Ebashi for preparation of troponin is recommended.
|Original language||English (US)|
|Number of pages||19|
|Journal||Acta Biochimica Polonica|
|State||Published - Dec 1 1973|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)