Abstract
Bovine cardiac troponin C was cleaved at residues cysteine-35 and cysteine-84. Three peptides, N-terminal (residues 1-34), central (residues 35-83) and C-terminal (residues 84-161), of cardiac troponin C were obtained in a homogeneous state. Saturation of troponin C or its C-terminal peptide with Ca2+ or Mg2+ is accompanied by an increase in the ellipticity at 222 nm in the c.d. spectrum. The half-maximal changes in the ellipticity of troponin C were observed at 32 nM-Ca2+ or 56 microM-Mg2+. The corresponding values for the C-terminal peptide are 7.1 nM for Ca2+ and 4.5 microM for Mg2+. The ellipticity of the central peptide (residues 35-83) containing the second cation-binding site was decreased on saturation with Ca2+. The half-maximal changes in the ellipticity occur at 80 microM-Ca2+. Study of the c.d. spectra suggests that the alpha-helices flanking the second cation-binding site of cardiac troponin C exist independently of Ca2+. Saturation of the third and fourth sites with these cations is associated with a considerable increase in the alpha-helix content, probably due to the formation of an alpha-helix flanking the third site on the N-terminus.
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- Adelstein R. S., Eisenberg E. Regulation and kinetics of the actin-myosin-ATP interaction. Annu Rev Biochem. 1980;49:921–956. doi: 10.1146/annurev.bi.49.070180.004421. [DOI] [PubMed] [Google Scholar]
- Barskaia N. V., Gusev N. B. Troponin serdtsa byka: vydelenie i izuchenie kationsviazyvaiushchikh svoistv s pomoshch'iu fluorestsentnogo zonda dimetilaminoaftérodina. Biokhimiia. 1981 Mar;46(3):495–503. [PubMed] [Google Scholar]
- Barskaya N. V., Gusev N. B. Biological activities of bovine cardiac-muscle troponin C C-terminal peptide (residues 84-161). Biochem J. 1982 Nov 1;207(2):185–192. doi: 10.1042/bj2070185. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brzeska H., Venyaminov SVu, Grabarek Z., Drabikowski W. Comparative studies on thermostability of calmodulin, skeletal muscle troponin C and their tryptic fragments. FEBS Lett. 1983 Mar 7;153(1):169–173. doi: 10.1016/0014-5793(83)80141-0. [DOI] [PubMed] [Google Scholar]
- Burtnick L. D., Kay C. M. The calcium-binding properties of bovine cardiac troponin C. FEBS Lett. 1977 Mar 15;75(1):105–110. doi: 10.1016/0014-5793(77)80063-x. [DOI] [PubMed] [Google Scholar]
- Chen Y. H., Yang J. T. A new approach to the calculation of secondary structures of globular proteins by optical rotatory dispersion and circular dichroism. Biochem Biophys Res Commun. 1971 Sep 17;44(6):1285–1291. doi: 10.1016/s0006-291x(71)80225-5. [DOI] [PubMed] [Google Scholar]
- Chou P. Y., Fasman G. D. Prediction of protein conformation. Biochemistry. 1974 Jan 15;13(2):222–245. doi: 10.1021/bi00699a002. [DOI] [PubMed] [Google Scholar]
- Evans J. S., Levine B. A., Leavis P. C., Gergely J., Grabarek Z., Drabikowski W. Proton magnetic resonance studies on proteolytic fragments of troponin-C. Structural homology with the native molecule. Biochim Biophys Acta. 1980 May 29;623(1):10–20. doi: 10.1016/0005-2795(80)90003-3. [DOI] [PubMed] [Google Scholar]
- Hennessey J. P., Jr, Johnson W. C., Jr Information content in the circular dichroism of proteins. Biochemistry. 1981 Mar 3;20(5):1085–1094. doi: 10.1021/bi00508a007. [DOI] [PubMed] [Google Scholar]
- Holroyde M. J., Robertson S. P., Johnson J. D., Solaro R. J., Potter J. D. The calcium and magnesium binding sites on cardiac troponin and their role in the regulation of myofibrillar adenosine triphosphatase. J Biol Chem. 1980 Dec 25;255(24):11688–11693. [PubMed] [Google Scholar]
- Johnson J. D., Collins J. H., Robertson S. P., Potter J. D. A fluorescent probe study of Ca2+ binding to the Ca2+-specific sites of cardiac troponin and troponin C. J Biol Chem. 1980 Oct 25;255(20):9635–9640. [PubMed] [Google Scholar]
- Kanellis P., Yang J., Cheung H. C., Lenkinski R. E. Synthetic peptide analogs of skeletal troponin C: fluorescence studies of analogs of the low-affinity calcium-binding site II. Arch Biochem Biophys. 1983 Feb 1;220(2):530–540. doi: 10.1016/0003-9861(83)90444-7. [DOI] [PubMed] [Google Scholar]
- Kohama K. Divalent cation binding properties of slow skeletal muscle troponin in comparison with those of cardiac and fast skeletal muscle troponins. J Biochem. 1979 Sep;86(3):811–820. doi: 10.1093/oxfordjournals.jbchem.a132589. [DOI] [PubMed] [Google Scholar]
- Kretsinger R. H. Structure and evolution of calcium-modulated proteins. CRC Crit Rev Biochem. 1980;8(2):119–174. doi: 10.3109/10409238009105467. [DOI] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Leavis P. C., Kraft E. L. Calcium binding to cardiac troponin C. Arch Biochem Biophys. 1978 Mar;186(2):411–415. doi: 10.1016/0003-9861(78)90453-8. [DOI] [PubMed] [Google Scholar]
- Leavis P. C., Rosenfeld S. S., Gergely J., Grabarek Z., Drabikowski W. Proteolytic fragments of troponin C. Localization of high and low affinity Ca2+ binding sites and interactions with troponin I and troponin T. J Biol Chem. 1978 Aug 10;253(15):5452–5459. [PubMed] [Google Scholar]
- Lux S. E., Hirz R., Shrager R. I., Gotto A. M. The influence of lipid on the conformation of human plasma high density apolipoproteins. J Biol Chem. 1972 Apr 25;247(8):2598–2606. [PubMed] [Google Scholar]
- Mani R. S., Boyes B. E., Kay C. M. Physicochemical and optical studies on calcium- and potassium-induced conformational changes in bovine brain S-100b protein. Biochemistry. 1982 May 25;21(11):2607–2612. doi: 10.1021/bi00540a005. [DOI] [PubMed] [Google Scholar]
- Nagy B., Gergely J. Extent and localization of conformational changes in troponin C caused by calcium binding. Spectral studies in the presence and absence of 6 M urea. J Biol Chem. 1979 Dec 25;254(24):12732–12737. [PubMed] [Google Scholar]
- Nagy B., Potter J. D., Gergely J. Calcium-induced conformational changes in a cyanogen bromide fragment of troponin C that contains one of the binding sites. J Biol Chem. 1978 Sep 10;253(17):5971–5974. [PubMed] [Google Scholar]
- Perry S. V. The regulation of contractile activity in muscle. Biochem Soc Trans. 1979 Aug;7(4):593–617. doi: 10.1042/bst0070593. [DOI] [PubMed] [Google Scholar]
- Potter J. D., Gergely J. The calcium and magnesium binding sites on troponin and their role in the regulation of myofibrillar adenosine triphosphatase. J Biol Chem. 1975 Jun 25;250(12):4628–4633. [PubMed] [Google Scholar]
- Reid R. E., Clare D. M., Hodges R. S. Synthetic analog of a high affinity calcium binding site in rabbit skeletal troponin C. J Biol Chem. 1980 Apr 25;255(8):3642–3646. [PubMed] [Google Scholar]
- Reid R. E., Gariépy J., Saund A. K., Hodges R. S. Calcium-induced protein folding. Structure-affinity relationships in synthetic analogs of the helix-loop-helix calcium binding unit. J Biol Chem. 1981 Mar 25;256(6):2742–2751. [PubMed] [Google Scholar]
- Reid R. E., Hodges R. S. Co-operativity and calcium/magnesium binding to troponin C and muscle calcium binding parvalbumin: an hypothesis. J Theor Biol. 1980 Jun 7;84(3):401–444. doi: 10.1016/s0022-5193(80)80013-0. [DOI] [PubMed] [Google Scholar]
- Siegel J. B., Steinmetz W. E., Long G. L. A computer-assisted model for estimating protein secondary structure from circular dichroic spectra: comparison of animal lactate dehydrogenases. Anal Biochem. 1980 May 1;104(1):160–167. doi: 10.1016/0003-2697(80)90292-4. [DOI] [PubMed] [Google Scholar]
- Spector T. Refinement of the coomassie blue method of protein quantitation. A simple and linear spectrophotometric assay for less than or equal to 0.5 to 50 microgram of protein. Anal Biochem. 1978 May;86(1):142–146. doi: 10.1016/0003-2697(78)90327-5. [DOI] [PubMed] [Google Scholar]
- Stull J. T., Buss J. E. Calcium binding properties of beef cardiac troponin. J Biol Chem. 1978 Sep 10;253(17):5932–5938. [PubMed] [Google Scholar]
- Tsukui R., Ebashi S. Cardiac troponin. J Biochem. 1973 May;73(5):1119–1121. doi: 10.1093/oxfordjournals.jbchem.a130168. [DOI] [PubMed] [Google Scholar]
- Weber K., Osborn M. The reliability of molecular weight determinations by dodecyl sulfate-polyacrylamide gel electrophoresis. J Biol Chem. 1969 Aug 25;244(16):4406–4412. [PubMed] [Google Scholar]
- van Eerd J. P., Takahshi K. Determination of the complete amino acid sequence of bovine cardiac troponin C. Biochemistry. 1976 Mar 9;15(5):1171–1180. doi: 10.1021/bi00650a033. [DOI] [PubMed] [Google Scholar]
