Assignments of sup 15 N and sup 1 H NMR resonances and a neutral pH ionization in Rhodospirillum rubrum cytochrome c sub 2

Journal Article · Tue Mar 27 04:00:00 EST 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00464a004· OSTI ID:6277619

Yu, Liping P; Smith, G M ^[1]

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1. Univ. of California, Davis (USA)

The {pi}NH proton and {sup 15}N resonances of the ligand histidine of Rhodospirillum rubrum ferricytochrome c{sub 2} 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 {pi} nitrogen in both oxidation states, indicating that the {pi}NH-peptide carboxyl hydrogen bond is not substantially weakened by the substitution. The proton and {sup 15}N 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.

• OSTI ID: 6277619
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 29:12; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
AMMONIUM CHLORIDES
AMMONIUM COMPOUNDS
AMMONIUM HALIDES
AZOLES
BACTERIA
BARYONS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CHEMICAL SHIFT
CHLORIDES
CHLORINE COMPOUNDS
CYTOCHROMES
DRUGS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
HALIDES
HALOGEN COMPOUNDS
HEAVY WATER
HEME
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HISTIDINE
HYDROGEN COMPOUNDS
IMIDAZOLES
IONIZATION
ISOTOPES
LIGANDS
LIGHT NUCLEI
LIPOTROPIC FACTORS
MAGNETIC RESONANCE
METHIONINE
MICROORGANISMS
MOLECULAR STRUCTURE
NITROGEN 15
NITROGEN ISOTOPES
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDATION
OXYGEN COMPOUNDS
PH VALUE
PIGMENTS
PORPHYRINS
PROTEINS
PROTONS
RESONANCE
RHODOSPIRILLUM
STABLE ISOTOPES
WATER