ISSN:
1573-5001
Keywords:
cytochromes
;
magnetic susceptibility anisotropy
;
paramagnetism
;
residual dipolar couplings
;
solution structure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract 15N-1H 1J couplings were measured at 500 MHz and 800 MHz for 15N enriched oxidized cytochrome b 562 from E. coli. The magnetic field dependence of 70 1J values, which could be measured without signal overlap, shows that there is a molecular magnetic anisotropy which provides partial molecular orientation in the magnetic field and, consequently, residual dipolar couplings (rdc). The rdc were used as further constraints to improve the existing structure [Arnesano et al. (1999) Biochemistry, 38, 8657–8670] with a protocol which uses the rhombic anisotropy [Banci et al. (1998) J. Am. Chem. Soc., 120, 12903–12909]. The overall large molecular magnetic anisotropy has been found to be determined by both the low spin iron (III) and the four helix bundle structure magnetic susceptibility anisotropy contributions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008308501053
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