Analysis of the Cob(II)alamin-5'-deoxy-3',4'-anhydroadenosyl radical triplet spin system in the active site of diol dehydrase.

Analysis of the Cob(II)alamin-5'-deoxy-3',4'-anhydroadenosyl radical triplet spin system in the active site of diol dehydrase. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

Analysis of the Cob(II)alamin-5'-deoxy-3',4'-anhydroadenosyl radical triplet spin system in the active site of diol dehydrase. Abstract Text:

Steven O Mansoorabadi,Olafur Th Magnusson,Russell R Poyner,Perry A Frey,George H Reed,

A triplet spin system (S=1) is detected by low-temperature electron paramagnetic resonance (EPR) spectroscopy in samples of diol dehydrase and the functional adenosylcobalamin (AdoCbl) analogue 5'-deoxy-3',4'-anhydroadenosylcobalamin (anAdoCbl). Different spectra are observed in the presence and absence of the substrate (R,S)-1,2-propanediol. In both cases, the spectra include a prominent half-field transition (DeltaM(S) = 2) that is a hallmark of strongly coupled triplet spin systems. The appearance of 59Co hyperfine splitting in the EPR signals and the positions (g values) of the signals in the spectra show that half of the triplet spin is contributed by the low-spin Co2+ of cob(II)alamin. Line width effects from isotopic labeling (13C and 2H) in the 5'-deoxy-3',4'-anhydroribosyl ring demonstrate that the other half of the spin triplet is from an allylic 5'-deoxy-3',4'-anhydroadenosyl (anhydroadenosyl) radical. The zero-field splitting (ZFS) tensors describing the magnetic dipole-dipole interactions of the component spins of the triplets have rhombic symmetry because of electron spin delocalization within the organic radical component and the proximity of the radical to the low-spin Co2+. The dipole-dipole interaction was modeled as a summation of point-dipole interactions involving the spin-bearing orbitals of the anhydroadenosyl radical and cob(II)alamin. Geometries which are consistent with the ZFS tensors in the presence and absence of the substrate position the 5'-carbon of the anhydroadenosyl radical 3.5 and 4.1 A from Co2+, respectively. Homolytic cleavage of the cobalt-carbon bond of the analogue in the absence of the substrate indicates that, in diol dehydrase, binding of the coenzyme to the protein weakens the bond prior to binding of the substrate.

Analysis of the Cob(II)alamin-5'-deoxy-3',4'-anhydroadenosyl radical triplet spin system in the active site of diol dehydrase. Publishing Authors By Initials

SO Mansoorabadi,OT Magnusson,RR Poyner,PA Frey,GH Reed,

For similar heterocyclic compounds: heterocyclic compounds, 1-ring: azoles: pyrroles: tetrapyrroles: corrinoids: vitamin b 12 research abstracts see: heterocyclic compounds: heterocyclic compounds, 1-ring: azoles: pyrroles: tetrapyrroles: corrinoids: vitamin b 12 research

PUBMED ID PMID:

MEDLINE DATE:

Analysis of the Cob(II)alamin-5'-deoxy-3',4'-anhydroadenosyl radical triplet spin system in the active site of diol dehydrase. Journal Published:

PUBLICATION TYPE: Research Support, N.I.H., Extr

Journal: Biochemistry

VOLUME: 45

Page Numbers: 14362-70

Journal Abbreviation: Biochemistry

ISSN: 0006-2960

DAY: 5

MONTH: Dec

YEAR: 2006

Analysis of the Cob(II)alamin-5'-deoxy-3',4'-anhydroadenosyl radical triplet spin system in the active site of diol dehydrase. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 370623

Analysis of the Cob(II)alamin-5'-deoxy-3',4'-anhydroadenosyl radical triplet spin system in the active site of diol dehydrase. Keywords Mesh Terms:

KEYWORDS: Vitamin B 12

MESH TERMS: metabolism

Chemical & Substance for Abstract: Analysis of the Cob(II)alamin-5'-deoxy-3',4'-anhydroadenosyl radical triplet spin system in the active site of diol dehydrase. Information

Substance Name: Propanediol Dehydratase

Registry Number: EC 4.2.1.28

Grant and Affiliation Information for Analysis of the Cob(II)alamin-5'-deoxy-3',4'-anhydroadenosyl radical triplet spin system in the active site of diol dehydrase.

AFFILIATION: Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53726-4087, USA.

Country: United States

AGENCY: United States NIGMS

GRANT: T32 GM08293

ACRONYM: GM

MEDLINETA: Biochemistry

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

Analysis of the CobIIalamin-5'-deoxy-3',4'-anhydroadenosyl radical triplet spin system in the active site of diol dehydrase Related Publications

• 14th International HLA and Immunogenetics Workshop: report on understanding antibodies in transplantation.
• A Gynecologic Oncology Group study of platinum-DNA adducts and excision repair cross-complementation group 1 expression in optimal, stage III epithelial ovarian cancer treated with platinum-taxane chemotherapy.
• A locus on mouse Chromosome 9 (Adip5) affects the relative weight of the gonadal but not retroperitoneal adipose depot.
• A phagocytosis mutant of Entamoeba histolytica is less virulent due to deficient proteinase expression and release.
• An infrared nuNH scale for weakly basic anions. Implications for single-molecule acidity and superacidity.
• An interferon signature in the peripheral blood of dermatomyositis patients is associated with disease activity.
• Analysis of the Cob(II)alamin-5'-deoxy-3',4'-anhydroadenosyl radical triplet spin system in the active site of diol dehydrase.
• Biochemical and functional comparisons of Mcl-1 and Bcl-2 proteins: evidence for a novel mechanism of regulating Bcl-2 family protein function.
• Bioinformatic identification of tandem repeat antigens of the Leishmania donovani complex.
• Cathepsin Cs are key for the intracellular survival of the protozoan parasite, Toxoplasma gondii.
• Daxx represses expression of a subset of antiapoptotic genes regulated by nuclear factor-kappaB.
• Deregulated cyclin E promotes p53 loss of heterozygosity and tumorigenesis in the mouse mammary gland.
• Do sitting-atop metalloporphyrin complexes exist? Observation of N-H- - -pi bonding in arene solvates of a diprotonated porphyrin dication.
• Effects of question format and collection mode on the accuracy of retrospective surveys of health risk behavior: a comparison with daily sexual activity diaries.
• Fertility of ewes following artificial insemination with semen frozen in pellets or straws, a preliminary report.
• Free radical mechanisms in enzymology.
• Frequency and amplitude discrimination along the kinestheticcutaneous continuum in the presence of masking stimuli.
• HBXIP, cellular target of hepatitis B virus oncoprotein, is a regulator of centrosome dynamics and cytokinesis.
• IR spectrum of the H(5)O(2)(+) cation in the context of proton disolvates L-H(+)-L.
• Mammalian dap3 is an essential gene required for mitochondrial homeostasis in vivo and contributing to the extrinsic pathway for apoptosis.
• Mice lacking bi-1 gene show accelerated liver regeneration.
• Nur77 converts phenotype of Bcl-B, an antiapoptotic protein expressed in plasma cells and myeloma.
• Pediatric respiratory and systemic effects of chronic air pollution exposure: nose, lung, heart, and brain pathology.
• Physician patterns of metabolic screening for patients taking atypical antipsychotics: a retrospective database study.
• Probing nitrogen-sensitive steps in the free-radical-mediated deamination of amino alcohols by ethanolamine ammonia-lyase.
• Reasons for unprotected intercourse: analysis of the PRAMS survey.
• Reconstituted NALP1 inflammasome reveals two-step mechanism of caspase-1 activation.
• Scope of practice for public health professionals and volunteers.
• The empirical relationship between community social capital and the demand for cigarettes.
• Ubiquitin-conjugating enzyme Ubc13 is a critical component of TNF receptor-associated factor (TRAF)-mediated inflammatory responses.