Abstract
A 25 kDa fragment of β-type troponin T (β-TnT) was expressed in Escherichia coli, and its function as a component of the regulatory system for actomyosin ATPase was compared with that of the authentic counterpart, the full length α-TnT. The expressed species, designated as β-TnT (N'-208), consists of 208 residues. It lacks the entire variable region at the amino-terminus and, near the carboxyl-terminus, a segment of 14 residues is changed from the α-type to the β-type sequence. Functional tests indicated that the truncated β-TnT was not distinguishable from the full length α-TnT, suggesting that neither deletion of the variable N-terminal region nor alteration of the type has a significant effect on the regulatory action of TnT.
