Saturation magnetization of Ni(II) in metalloproteins and model compounds

Conference · Wed Jan 01 00:00:00 EST 1992 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:6992286

Sendova, M; Day, E P; Kiick, K; Johnson, M; Ma, L; Scott, B; Hausinger, R; Todd, M; Peterson, J ^[1]

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1. Emory Univ., Atlanta, GA (United States) Univ. of Georgia, Athens (United States) Michigan State Univ., East Lansing (United States) Univ. of Alabama, Tuscaloosa (United States)

The Ni(II) sites of urease (from Klebsiella aerogenes and jack bean), coenzyme F[sub 430] (from Methanobacterium thermoautotrophicum), and several model compounds having octahedral symmetry have been studied using the saturation megnetization technique. Data were collected at four fixed fields over the temperature range from 2 - 200K. Theoretical curves calculated from the spin Hamiltonian were used to fit the experimentally obtained magnetization curves. The following parameters were determined: the spine state (S), the amount of the sample in this spin state ([S]), the gyromagnetic ratio (g), and the zero field splitting parameters (D, E/D). The amount of S=1 paramagnetism of the Ni(II) sites was found to depend on the pH of the buffer and on the concentration of the protein in D[sub 2]O (for coenzyme F[sub 430]). The relationship of the strength of the ligand field to the zero field splitting parameter was studied for the model compounds. There was no evidence for exchange coupling between the two Ni(II) ions at the active sites of either plant or bacterial urease.

• OSTI ID: 6992286
• Report Number(s): CONF-9202109-; CODEN: FAJOEC
• Journal Information: FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Vol. 6:1; Conference: American Society for Biochemistry and Molecular Biology and Biophysical Society joint meeting, Houston, TX (United States), 9-13 Feb 1992; ISSN 0892-6638
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
METALLOPROTEINS
BIOSYNTHESIS
NICKEL
METABOLISM
UREASE
ENZYME ACTIVITY
KLEBSIELLA
METHANOGENIC BACTERIA
AMIDINASES
BACTERIA
ELEMENTS
ENZYMES
HYDROLASES
METALS
MICROORGANISMS
NON-PEPTIDE C-N HYDROLASES
ORGANIC COMPOUNDS
PROTEINS
SYNTHESIS
TRANSITION ELEMENTS
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