Isolation and Characterization of Troponin from Abdominal Muscle of Prawn Penaeus japonicus

Abstract

Troponin, which confers high Ca2+-sensitivity to rabbit reconstituted actomyosin, was isolated from the abdominal muscle of prawn Penaeus japonicus. SDS-polyacrylamide gel electrophoresis showed that the prawn troponin consists of three components of Mr 17,000, 30,000-32,000 (doublet), and 42,000 in a molar ratio of 1:1:1, but Mr 52,000-59,000 component, which had been reported to be a troponin-T-like protein in arthropod troponin, was not found. The three components were separated from each other by DEAE-Toyopearl column chromatography in the presence of 6 M urea, and assigned as troponin-C, troponin-I, and troponin-T in increasing order of molecular weight. These features were basically identical with those of American lobster troponin of our previous study (Nishita and Ojima, J. Biochem., 108, 677-683 (1990)). © 1995, The Japanese Society of Fisheries Science. All rights reserved.