5478
Biochemistry 1999, 38, 5478-5489
Defining the Region of Troponin-I that Binds to Troponin-C† Ryan T. McKay, Brian P. Tripet, Joyce R. Pearlstone, Lawrence B. Smillie, and Brian D. Sykes* MRC Group in Protein Structure and Function, Department of Biochemistry, 474 Medical Sciences Building, UniVersity of Alberta, Canada T6G 2H7 ReceiVed December 17, 1998; ReVised Manuscript ReceiVed February 23, 1999
ABSTRACT: The kinetics and energetics of the binding of three troponin-I peptides, corresponding to regions 96-131 (TnI96-131), 96-139 (TnI96-139), and 96-148 (TnI96-148), to skeletal chicken troponin-C were investigated using multinuclear, multidimensional NMR spectroscopy. The kinetic off-rate and dissociation constants for TnI96-131 (400 s-1, 32 µM), TnI96-139 (65 s-1,
