Bovine cardiac troponin subunits: binary complexes and reconstitution of whole troponin

[摘要]

The reconstitution of bovine cardiac troponin from its subunits has been investigated using hydrodynamic techniques. Gel filtration (Sephacryl S-300) and sedimentation velocity experiments indicate that troponin-C and troponin-I from a stable binary complex (1:1 mole ratio) with an apparent Stokes' radius of 36 Å (frictional ratio = 1.6). Troponin-C and troponin-T do not interact significantly while troponin-I and troponin-T undergo partial complex formation. The effect of subunit ratio on the reconstitution of whole troponin has been examined by SDS—polyacrylamide gel electrophoresis and gel filtration and the results suggest that native troponin contains the subunits in an equimolar ratio.

[学科分类] 生物化学/生物物理

[关键词] Troponin;Cardiac muscle;Hydrodynamics;Gel filtration;Ultracentrifugation;TN-C;TN-T and TN-I;Ca2+-binding;tropomyosin-binding and inhibitory subunits of troponin;respectively;DTT;dithiothreitol;Mops;3-(N-morpholino)propanesulfonic acid;EGTA;ethylene glycol bis(β-aminoethyl ether)-N;N;N';N'-tetraacetic acid;NMED buffer;NaCl;50 mM Mops;1 mM EGTA and 2 mM DTT.