The Yin-Yang of cobalamin biochemistry.

The cobalamins are B12 cofactors with a reactive cobalt-carbon bond at their core and support the activity of two mammalian enzymes that are both medically important. The reactive organometallic bond of the cofactor can be cleaved either homolytically or heterolytically, but what determines how the enzymes control the fate of this bond?

[1]  J. Grate,et al.  CHEMISTRY OF COBALAMINS AND RELATED COMPOUNDS. 48. STERICALLY INDUCED, SPONTANEOUS DEALKYLATION OF SECONDARY ALKYLCOBALAMINS DUE TO AXIAL BASE COORDINATION AND CONFORMATIONAL CHANGES OF THE CORRIN LIGAND , 1979 .

[2]  K. Folkers,et al.  Crystalline Vitamin B12. , 1948, Science.

[3]  R. Matthews,et al.  Cobalamin-dependent methionine synthase from Escherichia coli B: electron paramagnetic resonance spectra of the inactive form and the active methylated form of the enzyme. , 1988, Biochemistry.

[4]  R. Matthews,et al.  Participation of cob(I) alamin in the reaction catalyzed by methionine synthase from Escherichia coli: a steady-state and rapid reaction kinetic analysis. , 1990, Biochemistry.

[5]  R. Matthews,et al.  How a protein binds B12: A 3.0 A X-ray structure of B12-binding domains of methionine synthase. , 1994, Science.

[6]  M. Summers,et al.  The structure of a B12 coenzyme: methylcobalamin studies by x-ray and NMR methods , 1985 .

[7]  R. Matthews,et al.  A protein radical cage slows photolysis of methylcobalamin in methionine synthase from Escherichia coli. , 1996, Bioorganic & medicinal chemistry.

[8]  S. Ragsdale,et al.  A Methylnickel Intermediate in a Bimetallic Mechanism of Acetyl-Coenzyme A Synthesis by Anaerobic Bacteria , 1995, Science.

[9]  J. Halpern,et al.  Why does nature not use the porphyrin ligand in vitamin B12 , 1987 .

[10]  R. Konrat,et al.  Direct Evidence for the Conformational Deformation of the Corrin Ring by the Nucleotide Base in Vitamin B12: Synthesis and Solution Spectroscopic and Crystal Structure Analysis of Co.beta.-Cyanoimidazolylcobamide , 1994 .

[11]  P. Leadlay,et al.  Cloning and structural characterization of the genes coding for adenosylcobalamin-dependent methylmalonyl-CoA mutase from Propionibacterium shermanii. , 1989, The Biochemical journal.

[12]  H. Weissbach,et al.  A COENZYME CONTAINING PSEUDOVITAMIN B(12). , 1958, Proceedings of the National Academy of Sciences of the United States of America.

[13]  J. Halpern.  Mechanisms of coenzyme B12-dependent rearrangements. , 1985, Science.

[14]  R. Banerjee,et al.  Magnetic field effects on coenzyme B12-dependent enzymes: validation of ethanolamine ammonia lyase results and extension to human methylmalonyl CoA mutase. , 1997, Bioelectromagnetics.

[15]  S. Ragsdale,et al.  Mössbauer, EPR, and optical studies of the corrinoid/iron-sulfur protein involved in the synthesis of acetyl coenzyme A by Clostridium thermoaceticum. , 1987, The Journal of biological chemistry.

[16]  R. Matthews,et al.  Mechanism of reductive activation of cobalamin-dependent methionine synthase: an electron paramagnetic resonance spectroelectrochemical study. , 1990, Biochemistry.

[17]  D. Ledbetter,et al.  Mapping of human methylmalonyl CoA mutase (MUT) locus on chromosome 6. , 1988, American journal of human genetics.

[18]  K. Brown,et al.  Heteronuclear NMR studies of cobalamins. 3. Phosphorus-31 NMR of aquocobalamin and various organocobalamins , 1984 .

[19]  H. Weissbach,et al.  Purification and properties of 5-methyltetrahydropteroyltriglutamate-homocysteine transmethylase. , 1970, The Journal of biological chemistry.

[20]  R. Banerjee,et al.  Evidence that cobalt-carbon bond homolysis is coupled to hydrogen atom abstraction from substrate in methylmalonyl-CoA mutase. , 1997, Biochemistry.

[21]  S. Ragsdale,et al.  The reductive acetyl coenzyme A pathway: sequence and heterologous expression of active methyltetrahydrofolate:corrinoid/iron-sulfur protein methyltransferase from Clostridium thermoaceticum , 1994, Journal of bacteriology.

[22]  F. Ledley,et al.  Mutations in mut methylmalonic acidemia: Clinical and enzymatic correlations , 1997, Human mutation.

[23]  S. C. Choi,et al.  Vitamin B12S-promoted model rearrangement of methylmalonate to succinate is not a free radical reaction. , 1990, Proceedings of the National Academy of Sciences of the United States of America.

[24]  J. M. Pratt,et al.  The chemistry of vitamin B 12. , 1969, Chemistry in Britain.

[25]  J. Stubbe,et al.  Thiyl Radicals in Ribonucleotide Reductases , 1996, Science.

[26]  G. Örlygsson,et al.  Evidence for a Mechanism Involving Transient Fragmentation in Carbon Skeleton Rearrangements Dependent on Coenzyme B12 , 1995 .

[27]  M. Malinow,et al.  Hyperhomocyst(e)inemia as a risk factor for occlusive vascular disease. , 1992, Annual review of nutrition.

[28]  W. Fenton,et al.  Cloning of full-length methylmalonyl-CoA mutase from a cDNA library using the polymerase chain reaction. , 1989, Genomics.

[29]  R. Banerjee,et al.  Cloning, mapping and RNA analysis of the human methionine synthase gene. , 1996, Human molecular genetics.

[30]  J. Stubbe,et al.  Binding site revealed of nature's most beautiful cofactor. , 1994, Science.

[31]  P. Goyette,et al.  Human methionine synthase: cDNA cloning and identification of mutations in patients of the cblG complementation group of folate/cobalamin disorders. , 1996, Human molecular genetics.

[32]  P. Leadlay,et al.  How coenzyme B12 radicals are generated: the crystal structure of methylmalonyl-coenzyme A mutase at 2 A resolution. , 1996, Structure.

[33]  F. Ng,et al.  Ligand effects on transition metal-alkyl bond dissociation energies , 1982 .

[34]  R. Matthews,et al.  Cobalamin‐dependent methionine synthase , 1990, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[35]  R. Matthews,et al.  Cobalamin-independent methionine synthase from Escherichia coli: a zinc metalloenzyme. , 1996, Biochemistry.

[36]  Y. Zhao,et al.  Electron paramagnetic resonance studies of the methylmalonyl-CoA mutase reaction. Evidence for radical intermediates using natural and artificial substrates as well as the competitive inhibitor 3-carboxypropyl-CoA. , 1994, European journal of biochemistry.

[37]  P. Leadlay,et al.  Tritium isotope effects in adenosylcobalamin-dependent methylmalonyl-CoA mutase. , 1996, Biochemistry.

[38]  B. Beatrix,et al.  Characterization of the coenzyme-B12-dependent glutamate mutase from Clostridium cochlearium produced in Escherichia coli. , 1994, European journal of biochemistry.

[39]  R. Banerjee,et al.  Evidence from Electron Paramagnetic Resonance Spectroscopy of the Participation of Radical Intermediates in the Reaction Catalyzed by Methylmalonyl-coenzyme A Mutase (*) , 1995, The Journal of Biological Chemistry.

[40]  L. Marzilli,et al.  An unusually long cobalt-carbon bond. Molecular structure of trans-bis(dimethylglyoximato)(isopropyl)(pyridine)cobalt(III). Implications with regard to the conformational trigger mechanism of cobalt-carbon bond cleavage in coenzyme B12 , 1979 .

[41]  R. Thauer,et al.  The corrinoid-containing 23-kDa subunit MtrA of the energy-conserving N5-methyltetrahydromethanopterin:coenzyme M methyltransferase complex from Methanobacterium thermoautotrophicum. EPR spectroscopic evidence for a histidine residue as a cobalt ligand of the cobamide. , 1996, European journal of biochemistry.

[42]  J. F. Kolhouse,et al.  Mechanism of conversion of human apo- to holomethionine synthase by various forms of cobalamin. , 1991, The Journal of biological chemistry.

[43]  K. Trueblood,et al.  Structure of Vitamin B12 , 1956, Nature.

[44]  B. Hay,et al.  Thermolysis of the cobalt-carbon bond in adenosylcorrins. 3. Quantification of the axial base effect in adenosylcobalamin by the synthesis and thermolysis of axial base-free adenosylcobinamide. Insights into the energetics of enzyme-assisted cobalt-carbon bond homolysis , 1987 .

[45]  M. Ratner,et al.  Gated electron transfer: when are observed rates controlled by conformational interconversion? , 1987 .

[46]  J. F. Kolhouse,et al.  Recognition of two intracellular cobalamin binding proteins and their identification as methylmalonyl-CoA mutase and methionine synthetase. , 1977, Proceedings of the National Academy of Sciences of the United States of America.

[47]  P. Dowd,et al.  First hydrogen abstraction-rearrangement model for the coenzyme B12-dependent methylmalonyl-CoA to succinyl-CoA carbon skeleton rearrangement reaction , 1992 .

[48]  R. Matthews,et al.  Interaction of Escherichia coli cobalamin-dependent methionine synthase and its physiological partner flavodoxin: binding of flavodoxin leads to axial ligand dissociation from the cobalamin cofactor. , 1997, Biochemistry.

[49]  H. Willard,et al.  Intracellular binding of radioactive hydroxocobalamin to cobalamin-dependent apoenzymes in rat liver. , 1977, Proceedings of the National Academy of Sciences of the United States of America.

[50]  G. Schrauzer,et al.  Reactions of cobalt(I) supernucleophiles. The alkylation of vitamin B12s cobaloximes(I), and related compounds. , 1969, Journal of the American Chemical Society.

[51]  R. Blumenthal,et al.  Assignment of enzymatic function to specific protein regions of cobalamin-dependent methionine synthase from Escherichia coli. , 1993, Biochemistry.

[52]  R. Matthews,et al.  Cloning and sequence analysis of the Escherichia coli metH gene encoding cobalamin-dependent methionine synthase and isolation of a tryptic fragment containing the cobalamin-binding domain. , 1989, The Journal of biological chemistry.

[53]  J. Rétey,et al.  Radical Intermediates in the Coenzyme B12 Dependent Methylmalonyl‐CoA Mutase Reaction Shown by ESR Spectroscopy , 1992 .

[54]  D. E. Holloway,et al.  Cloning and sequencing of glutamate mutase component S from Clostridium tetanomorphum Homologies with other cobalamin‐dependent enzymes , 1992, FEBS letters.

[55]  R. Banerjee,et al.  Coenzyme B12 Is Coordinated by Histidine and Not Dimethylbenzimidazole on Methylmalonyl-CoA Mutase , 1995 .

[56]  R. Matthews,et al.  The structure of the C-terminal domain of methionine synthase: presenting S-adenosylmethionine for reductive methylation of B12. , 1996, Structure.

[57]  R. Finke,et al.  Adenosylcobinamide, the Base-Free Analog of Coenzyme B12 (Adenosylcobalamin). 1.1 Probing the Role of the Axial 5,6-Dimethylbenzimidazole Base in Coenzyme B12 via Exogenous Axial Base Kassociation, ΔH, and ΔS Measurements plus a Critical Review of the Relevant Biochemical Literature , 1996 .

[58]  R. R. Williams.  Structure of vitamin B1. , 1935 .

[59]  J. Halpern,et al.  Cobalt-carbon bond dissociation energy of coenzyme B12 , 1984 .

[60]  J. Poston.  Leucine 2,3-aminomutase, an enzyme of leucine catabolism. , 1976, The Journal of biological chemistry.

[61]  Raymond L. Blakley,et al.  Cobamides and ribonucleotide reduction. XII. The electron paramagnetic resonance spectrum of "active coenzyme B12". , 1974, The Journal of biological chemistry.

[62]  P. Leadlay,et al.  The synthetic substrate succinyl(carbadethia)-CoA generates cob(II)alamin on adenosylcobalamin-dependent methylmalonyl-CoA mutase. , 1993, The Biochemical journal.

[63]  M. Lehmann,et al.  HIGH-RESOLUTION NEUTRON STUDY OF VITAMIN-B12 COENZYME AT 15-K - STRUCTURE-ANALYSIS AND COMPARISON WITH THE STRUCTURE AT 279-K , 1993 .

[64]  S. Friedman,et al.  A Methyl Analogue of Cobamide Coenzyme in Relation to Methionine Synthesis by Bacteria , 1962, Nature.

[65]  R. Matthews,et al.  Cobamide-dependent methyl transferases. , 1990, BioFactors.

[66]  J. Grate,et al.  Chemistry of cobalamins and related compounds. 48. Sterically induced, spontaneous dealkylation of secondary alkylcobalamins due to axial base coordination and conformational changes of the corrin ligand , 1979 .

[67]  R. Finke,et al.  Adocobalamin (AdoCbl or coenzyme B12) cobalt-carbon bond homolysis radical-cage effects: product, kinetic, mechanistic, and cage efficiency factor (Fc) studies, plus the possibility that coenzyme B12-dependent enzymes function as "ultimate radical cages" and "ultimate radical traps" , 1993 .

[68]  J. M. Pratt,et al.  The chemistry of vitamin B12. Part 19. Labilisation of the cobalt–carbon bond in organocobalamins by steric distortions; neopentyl-cobalamin as a model for labilisation of the vitamin B12 coenzymes , 1980 .

[69]  R. Banerjee,et al.  Defects in human methionine synthase in cblG patients. , 1996, Human molecular genetics.

[70]  B. Kräutler.  Thermodynamic trans-effects of the nucleotide base in the B12 coenzymes , 1987 .

[71]  F. M. Huennekens,et al.  Activation of methionine synthase: further characterization of flavoprotein system. , 1977, Archives of biochemistry and biophysics.

[72]  T. Garrow.  Purification, Kinetic Properties, and cDNA Cloning of Mammalian Betaine-Homocysteine Methyltransferase* , 1996, The Journal of Biological Chemistry.

[73]  R. Finke,et al.  Cobalt-carbon homolysis and bond dissociation energy studies of biological alkylcobalamins: methylcobalamin, including a.gtoreq.1015 Co-CH3 homolysis rate enhancement at 25.degree. following one-electron reduction , 1990 .

[74]  Kent J. Crippen,et al.  Purification and kinetic mechanism of a mammalian methionine synthase from pig liver. , 1994, The Journal of biological chemistry.

[75]  L. Poppe,et al.  [Omega-(adenosin-5'-O-yl)alkyl]cobalamins mimicking the posthomolysis intermediate of coenzyme B12-dependent rearrangements: kinetic investigations on methylmalonyl-CoA mutase. , 1995, Archives of biochemistry and biophysics.

[76]  J. Rétey,et al.  Nonenzymatic model reaction for the coenzyme B12-catalyzed rearrangement of methylmalonyl-CoA into succinyl-CoA. , 1975, Angewandte Chemie.

[77]  J. M. Puckett,et al.  Structural and electronic similarity but functional difference in methylmalonyl-CoA mutase between coenzyme B12 and the analog 2',5'-dideoxyadenosylcobalamin. , 1995, Biochemistry.

[78]  Mu He,et al.  Mechanism of Action of Vitamin B12. A New Test for Free Radical Intermediates Using a Cyclopropane Model for the Methylmalonyl-CoA to Succinyl-CoA Carbon Skeleton Rearrangement , 1996 .

[79]  J. M. Puckett,et al.  Near-IR FT-Raman Spectroscopy of Methyl-B12 and Other Cobalamins and of Imidazole and Imidazolate Methylcobinamide Derivatives in Aqueous Solution , 1996 .

[80]  U. Pandit,et al.  Model studies of the cobalamin-dependent methionine synthase reaction , 1993 .

[81]  J. Savéant,et al.  The electrochemistry of vitamin B12 , 1983 .

[82]  R. Matthews,et al.  Mutations in the B12-binding region of methionine synthase: how the protein controls methylcobalamin reactivity. , 1996, Biochemistry.

[83]  D. Hodgkin,et al.  Structure of the 5,6-Dimethylbenzimidazolylcobamide Coenzyme , 1961, Nature.

[84]  J. Halpern,et al.  Free radical rearrangement involving the 1,2-migration of a thioester group: model for the coenzyme B12 dependent methylmalonyl-CoA mutase reaction , 1984 .

[85]  J. Mills,et al.  Homocysteine metabolism in pregnancies complicated by neural-tube defects , 1995, The Lancet.

[86]  J. Rétey,et al.  Quantitative measurement of the error in the cryptic stereospecificity of methylmalonyl-CoA mutase. , 1987, European journal of biochemistry.