caa a22 4500 397555903 CHVBK 20180308164802.0 cr unu---uuuuu 161202e199601 xx s 000 0 eng 10.1093/oxfordjournals.jbchem.a021202 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jbchem.a021202 Yamamoto Yasuhiko Department of Chemistry, University of Tsukuba, Tsukuba, Ibaraki 305 1H-NMR Study of Temperature-Induced Structure Alteration at the Active Site of Horse Heart Cytochrome c [Elektronische Daten] [Yasuhiko Yamamoto] The molecular structure of the active site of horse heart met-cyano cytochrome c, as a function of temperature, has been investigated using 1H-NMR. A temperature dependence study of the NMR spectra revealed that one heme methyl proton resonance exhibits anti-Curie behavior, i.e., the hyperfine shift increases with increasing temperature. Analyses of the average heme methyl proton hyperfine shift and the proximal His imidazole proton resonances indicated that the iron-His bonding interaction in this protein is essentially independent of temperature. Since such an anomalous temperature dependence of the heme methyl proton resonance disappears in met-cyano complex of a heme peptide prepared by enzymatic degradation of the protein [Smith, M. and McLendon, G. (1981) J. Am. Chem. Soc. 103,4912-4921], the anti-Curie behavior observed for the heme methyl proton resonance in met-cyano cytochrome c is attributed to a rotational displacement of the heme about the iron-His bond relative to the protein moiety due to a temperature-dependent conformational alteration of the heme-protein linkage. Such rotational mobility of heme at the active site of a protein may be responsible for the anomalous temperature dependence of heme methyl proton hyperfine shifts reported for many c-type ferri cytochromes. © by the Journal of Biochemistry Regular Papers nationallicence Curie plot nationallicence cytochrome c nationallicence hemoprotein nationallicence hyperfine shift nationallicence NMR nationallicence The Journal of Biochemistry Oxford University Press 119/1(1996-01), 16-22 0021-924X 119:1<16 1996 119 jbchem https://doi.org/10.1093/oxfordjournals.jbchem.a021202 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jbchem.a021202 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Yamamoto Yasuhiko Department of Chemistry, University of Tsukuba, Tsukuba, Ibaraki 305 NATIONALLICENCE 773 0- The Journal of Biochemistry Oxford University Press 119/1(1996-01), 16-22 0021-924X 119:1<16 1996 119 jbchem Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford