sup 1 H NMR spectra of vertebrate (2Fe-2S) ferredoxins. Hyperfine resonances suggest different electron delocalization patterns from plant ferredoxins

Journal Article · Tue Sep 17 00:00:00 EDT 1991 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00101a024· OSTI ID:5821852

Skjeldal, L; Markley, J L ^[1]; Coghlan, V M; Vickery, L E ^[2]

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1. Univ. of Wisconsin, Madison (United States)
2. Univ. of California, Irvine (United States)

The authors report the observation of paramagnetically shifted (hyperfine) proton resonances from vertebrate mitochondrial (2Fe-2S) ferredoxins. The hyperfine signals of human, bovine, and chick (2Fe-2S) ferredoxins are described and compared with those of Anabena 7120 vegetative ferredoxin, a plant-type (2Fe-2S) ferredoxin studied previously. The hyperfine resonances of the three vertebrate ferredoxins were very similar to one another both in the oxidized state and in the reduced state, and slow (on the NMR scale) electron self-exchange was observed in partially reduced samples. For the oxidized vertebrate ferredoxins, hyperfine signals were observed downfield of the diamagnetic envelope from +13 to +50 ppm, and the general pattern of peaks and their anti-Curie temperature dependence are similar to those observed for the oxidized plant-type ferredoxins. For the reduced vertebrate ferredoxins, hyperfine signals were observed for the oxidized plant-type ferredoxins. For the reduced vertebrate ferredoxins, hyperfine signals were observed both upfield ({minus}2 to {minus}18 ppm) and downfield (+15 to +45 ppm), and all were found to exhibit Curie-type temperature dependence. These results indicate that the contact-shifted resonances in the reduced vertebrate ferredoxins detect different spin magnetization from those in the reduced plant ferredoxins and suggest that plant and vertebrate ferredoxins have fundamentally different patterns of electron delocalization in the reduced (2Fe-2S) center.

• OSTI ID: 5821852
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 30:37; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BARYONS
CELL CONSTITUENTS
CHEMICAL REACTIONS
ELEMENTARY PARTICLES
FERMIONS
FERREDOXIN
HADRONS
HEAVY WATER
HYDROGEN COMPOUNDS
HYPERFINE STRUCTURE
MAGNETIC RESONANCE
MAGNETISM
MAMMALS
MAN
METALLOPROTEINS
MITOCHONDRIA
NUCLEAR MAGNETIC RESONANCE
NUCLEONS
ORGANIC COMPOUNDS
OXIDATION
OXYGEN COMPOUNDS
PARAMAGNETISM
PRIMATES
PROTEINS
PROTONS
REDUCTION
RESONANCE
TEMPERATURE DEPENDENCE
VERTEBRATES
WATER