A Comparison of Spectral and Physicochemical Properties of Yeast Iso-1 Cytochrome C and Cys 102-modified Derivatives of the Protein

Overview

Journal J Protein Chem

Specialties Biochemistry
Chemistry

Date 1995 Oct 1

PMID 8561853

Citations 2

Authors

S J Moench

J D Satterlee

Affiliations

Soon will be listed here.

Abstract

Derivatives of yeast iso-1 cytochrome c, chemically modified at Cys-102 (Cys-102 acetamide-derivatized monomer, Cys-102 thionitrobenzoate-derivatized monomer, Cys-102 S-methylated monomer, and the disulfide dimer), exhibit different spectral and physicochemical properties relative to the native, unmodified protein, depending on the nature of the modifying group. The results of proton NMR studies on the Cys-102 acetamide-derivatized monomer of iso-1 ferricytochrome c indicate that the conformational characteristics of the heme environment in this protein derivative are intermediate between those of the unmodified monomer and disulfide dimer forms of the protein. Measurements of the pKa of the alkaline transitions of the five forms of iso-1 ferricytochrome c provided values of 8.89, 8.82, 8.67, 8.47, and 8.50 for the unmodified monomer, S-methylated monomer, acetamide-derivatized monomer, thionitrobenzoate-derivatized monomer, and disulfide dimer, respectively. The results of proton NMR studies of the reduced form of these proteins suggest that the heme environments of the unmodified monomer and disulfide dimer derivatives of iso-1 ferrocytochrome c are similar and indicate that treatment of the thionitrobenzoate-derivatized and disulfide dimer forms of the protein with sodium dithionite results in cleavage of the disulfide bonds at position 102. Circular dichroism studies reveal that only the disulfide dimer form of iso-1 ferricytochrome c exhibits a Soret CD spectrum which differs from the native, unmodified monomer in that the intensity of the negative band at approximately 420 nm is diminished in the spectrum of the dimer relative to the spectrum of the monomer. Soret CD spectra of the ascorbate-reduced form of all protein derivatives are similar. The process of "autoreduction" of yeast iso-1 ferricytochrome c is shown to occur in the absence of a free sulfhydryl group at position 102 and is exacerbated under moderately high pH conditions. These results are suggestive of the presence of a redox-active amino acid, perhaps a tyrosine, in yeast iso-1 cytochrome c.

Citing Articles

Cytochrome c conformations resolved by the photon counting histogram: watching the alkaline transition with single-molecule sensitivity.

Perroud T, Bokoch M, Zare R Proc Natl Acad Sci U S A. 2005; 102(49):17570-5.

PMID: 16314563 PMC: 1308922. DOI: 10.1073/pnas.0508975102.

Crystal structure of the yeast cytochrome bc1 complex with its bound substrate cytochrome c.

Lange C, Hunte C Proc Natl Acad Sci U S A. 2002; 99(5):2800-5.

PMID: 11880631 PMC: 122428. DOI: 10.1073/pnas.052704699.

References

Geren L, Hahm S, Durham B, Millett F . Photoinduced electron transfer between cytochrome c peroxidase and yeast cytochrome c labeled at Cys 102 with (4-bromomethyl-4'-methylbipyridine)[bis(bipyridine)]ruthenium2+. Biochemistry. 1991; 30(39):9450-7. DOI: 10.1021/bi00103a009. View

Greenwood C, Wilson M . Studies on ferricytochrome c. I. Effect of pH, ionic strength and protein denaturants on the spectra of ferricytochrome c. Eur J Biochem. 1971; 22(1):5-10. DOI: 10.1111/j.1432-1033.1971.tb01507.x. View

Osheroff N, Borden D, Koppenol W, MARGOLIASH E . Electrostatic interactions in cytochrome c. The role of interactions between residues 13 and 90 and residues 79 and 47 in stabilizing the heme crevice structure. J Biol Chem. 1980; 255(4):1689-97. View

Wand A, Di Stefano D, Feng Y, Roder H, Englander S . Proton resonance assignments of horse ferrocytochrome c. Biochemistry. 1989; 28(1):186-94. DOI: 10.1021/bi00427a026. View

Laemmli U . Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970; 227(5259):680-5. DOI: 10.1038/227680a0. View

Senn H, Eugster A, Wuthrich K . Determination of the coordination geometry at the heme iron in three cytochromes c from Saccharomyces cerevisiae and from Candida krusei based on individual 1H-NMR assignments for heme c and the axially coordinated amino acids. Biochim Biophys Acta. 1983; 743(1):58-68. DOI: 10.1016/0167-4838(83)90418-1. View

Parr G, Hantgan R, Taniuchi H . Formation of two alternative complementing structures from cytochrome c heme fragment (residue 1 to 38) and the apoprotein. J Biol Chem. 1978; 253(15):5381-8. View

Moench S, Satterlee J . Proton NMR comparison of the Saccharomyces cerevisiae ferricytochrome c isozyme-1 monomer and covalent disulfide dimer. J Biol Chem. 1989; 264(17):9923-31. View

Hoganson C, Babcock G . Protein-tyrosyl radical interactions in photosystem II studied by electron spin resonance and electron nuclear double resonance spectroscopy: comparison with ribonucleotide reductase and in vitro tyrosine. Biochemistry. 1992; 31(47):11874-80. DOI: 10.1021/bi00162a028. View

10.

MOTONAGA K, Katano H, Nakanishi K . STRUCTURE OF YEAST CYTOCHROME C. II. PROTEINASE DIGESTION AND ULTRAVIOLET DIFFERENCE SPECTRA. J Biochem. 1965; 57:29-33. DOI: 10.1093/oxfordjournals.jbchem.a128052. View

11.

Satterlee J, Moench S . Proton hyperfine resonance assignments using the nuclear Overhauser effect for ferric forms of horse and tuna cytochrome c. Biophys J. 1987; 52(1):101-7. PMC: 1329988. DOI: 10.1016/S0006-3495(87)83193-4. View

12.

Michel B, Proudfoot A, Wallace C, Bosshard H . The cytochrome c oxidase-cytochrome c complex: spectroscopic analysis of conformational changes in the protein-protein interaction domain. Biochemistry. 1989; 28(2):456-62. DOI: 10.1021/bi00428a008. View

13.

Ramdas L, Sherman F, Nall B . Guanidine hydrochloride induced equilibrium unfolding of mutant forms of iso-1-cytochrome c with replacement of proline-71. Biochemistry. 1986; 25(22):6952-8. DOI: 10.1021/bi00370a032. View

14.

Zuniga E, Nall B . Folding of yeast iso-1-AM cytochrome c. Biochemistry. 1983; 22(6):1430-7. DOI: 10.1021/bi00275a017. View

15.

Murphy M, Nall B, Brayer G . Structure determination and analysis of yeast iso-2-cytochrome c and a composite mutant protein. J Mol Biol. 1992; 227(1):160-76. DOI: 10.1016/0022-2836(92)90689-h. View

16.

Weber C, Michel B, Bosshard H . Spectroscopic analysis of the cytochrome c oxidase-cytochrome c complex: circular dichroism and magnetic circular dichroism measurements reveal change of cytochrome c heme geometry imposed by complex formation. Proc Natl Acad Sci U S A. 1987; 84(19):6687-91. PMC: 299148. DOI: 10.1073/pnas.84.19.6687. View

17.

Yonetani T, Ray G . Studies on cytochrome c peroxidase. I. Purification and some properties. J Biol Chem. 1965; 240(11):4503-8. View

18.

Sivaraja M, Goodin D, Smith M, Hoffman B . Identification by ENDOR of Trp191 as the free-radical site in cytochrome c peroxidase compound ES. Science. 1989; 245(4919):738-40. DOI: 10.1126/science.2549632. View

19.

DeFelippis M, Murthy C, Faraggi M, Klapper M . Pulse radiolytic measurement of redox potentials: the tyrosine and tryptophan radicals. Biochemistry. 1989; 28(11):4847-53. DOI: 10.1021/bi00437a049. View

20.

MARGOLIASH E, FROHWIRT N . Spectrum of horse-heart cytochrome c. Biochem J. 1959; 71(3):570-2. PMC: 1196833. DOI: 10.1042/bj0710570. View