Structural results relevant to the molybdenum sites in xanthine oxidase and sulfide oxidase. Crystal structures of MoO/sub 2/L, L = (SCH/sub 2/CH/sub 2/)/sub 2/NCH/sub 2/CH/sub 2/X with X = SCH/sub 3/, N(CH/sub 3/)/sub 2/

Journal Article · Wed May 09 04:00:00 EDT 1979 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00504a068· OSTI ID:6101903

Berg, J M ^[1]; Hodgson, K O; Cramer, S P; Corbin, J L; Elsberry, A; Pariyadath, N; Stiefel, E I

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1. Stanford Univ., CA

Single-crystal x-ray diffraction have been completed for these two compounds: (1) X = SCH/sub 3/; and (2) X = N(CH/sub 3/)/sub 2/. Bond angles and bond lengths are given. The x-ray absorption fine structure (EXAFS) analysis of 1 and 2 are compared with the spectra of oxidized forms of xanthine oxidase and sulfur oxidase. Curve fitting analysis of the data, in their oxidized forms, both enzymes contain the MoO/sub 2//sup 2 +/ unit. The average M=O distances, 1.71 A, are the same for both proteins. Sulfur atoms are present at average distances of 2.42 and 2.54 A for sulfite and xanthine oxidase, respectively. A more distant sulfur is present in both enzymes at 2.85 A. Similarities in the EXAFS spectra for 1 and sulfite oxidase Mo--O and Mo--S bond lengths are apparent. Comparisons of the Mo--S distances in the enzymes with those of 1 and 2 suggests configurational features about the molybdenum sites in the enzymes. The thiolate sulfurs in 1 and 2 are trans to each other and cis to the oxo groups with the Mo--thiolate distances all between 2.40 and 2.42 A. The distances are consistent with other known structures containing thiolates cis to Mo=O. Sulfite oxidase has similar Mo--S distances, but in xanthine oxidase a longer distance (2.54 A) is observed. Since a pronounced trans effect is known to exist for M=O bonds, this longer distance may be characteristic of a thiolate sulfur trans to a Mo--O. 2 figures, 1 table.

• OSTI ID: 6101903
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 101:10; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400104 -- Spectral Procedures-- (-1987)
400201 -- Chemical & Physicochemical Properties
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
550200 -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ABSORPTION SPECTRA
BOND ANGLE
BOND LENGTHS
COHERENT SCATTERING
COMPARATIVE EVALUATIONS
COMPLEXES
DATA
DATA FORMS
DIFFRACTION
ENZYMES
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
INFORMATION
ISOLATED VALUES
LIGANDS
MEASURING INSTRUMENTS
MOLYBDENUM COMPLEXES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANOMETALLIC COMPOUNDS
OXIDASES
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PURINES
SCATTERING
SPECTRA
SPECTROMETERS
STRUCTURAL CHEMICAL ANALYSIS
SULFITES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPLEXES
X-RAY DIFFRACTION
X-RAY SPECTROMETERS
XANTHINES