Spin and electron distributions in heme-cyanide models and hemeproteins
Yazarlar (3)
| Makale Türü | Özgün Makale (Uluslararası alan indekslerindeki dergilerde yayınlanan tam makale) | ||
| Dergi Adı | Biochimica et Biophysica Acta (BBA)-Protein Structure and Molecular Enzymology | ||
| Makale Dili | – | Basım Tarihi | 12-1985 |
| Cilt / Sayı / Sayfa | 832 / 3 / 265–273 | DOI | – |
| Makale Linki | https://www.sciencedirect.com/science/article/pii/0167483885902596 | ||
| UAK Araştırma Alanları |
Dedektör Teknolojisi
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| Özet |
| Proton NMR spectra of low-spin Fe(III) cyanoprotoheme as prosthetic group in a number of proteins are presented. The diagonally positioned 1-, 5- and 3-, 8-methyl groups obey shifts proportional to the Fe(III)/(II) reduction potential Em7, which indicates a pseudo-contact interaction. The correlation with Em7 is understandable if one postulates an enhanced rhombic distortion, dominating the Fe-methyl dipolar interactions. Hatree-Fock-Slater quantum chemical calculations show no significant changes of spin density as a function of the Fe-L5 distance, except at the iron atom and predominantly in the 3dxz and 3dyz orbitals. 4p orbitals, on the other hand, uphold most of the changes of electron density. We also observe a principal difference in the amino acid sequences in the heme-accommodating pocket of oxygen carriers and two-electron transmitters. |
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