Journal article
Assignments of nitrogen-15 and proton NMR resonances and a neutral pH ionization in Rhodospirillum rubrum cytochrome c2
Biochemistry (Easton), Vol.29(12), pp.2914-2919
03/01/1990
DOI: 10.1021/bi00464a004
Abstract
The πNH proton and 15N resonances of the ligand histidine of Rhodospirillum rubrum fer-ricytochrome c2 are found at 14.7 and 184 ppm, respectively, contradicting the proposal that this proton is absent in the R. rubrum ferricytochrome. Substitution of the deuterium atom for this proton causes small upfield shifts of the π nitrogen in both oxidation states, indicating that the πNH-peptide carboxyl hydrogen bond is not substantially weakened by the substitution. The proton and 15N resonances of the indolic NH group of the invariant tryptophan-62 and numerous proton resonances of the heme and extraheme ligands in the spectrum of the ferricytochrome are also assigned. An ionization in the ferrocytochrome occurring at neutral pH is assigned to the single nonligand histidine. This attribution is supported by the direct measurement of the ionization by NOE difference spectroscopy and by comparative structural arguments involving closely related cytochromes and chemically modified cytochromes.
Details
- Title: Subtitle
- Assignments of nitrogen-15 and proton NMR resonances and a neutral pH ionization in Rhodospirillum rubrum cytochrome c2
- Creators
- Liping P YuGary M Smith
- Resource Type
- Journal article
- Publication Details
- Biochemistry (Easton), Vol.29(12), pp.2914-2919
- Publisher
- American Chemical Society
- DOI
- 10.1021/bi00464a004
- ISSN
- 0006-2960
- eISSN
- 1520-4995
- Language
- English
- Date published
- 03/01/1990
- Academic Unit
- Biochemistry and Molecular Biology; Medicine Administration
- Record Identifier
- 9984627320202771
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