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Enhancing the Methyl-Donor Activity of Methylcobalamin by Covalent Attachment of DNA
- Source :
- Chemistry & Biodiversity. 2:178-197
- Publication Year :
- 2005
- Publisher :
- Wiley, 2005.
-
Abstract
- The preparation of a covalent DNA conjugate of vitamin B12 by means of heterogeneous solid-phase synthesis is reported. The cyano-corrinoid made available, dipotassium Co(beta)-cyanocobalamin-(3''-->2'),(3''-->5')-bis-2''-deoxythymidyl-3''-ate (K(2)-4), was cleanly methylated at the Co center by electrosynthetic means. Aqueous solutions of the resulting organometallic DNA-B12 conjugate K(2)-5 exhibited spectroscopic properties indicative of significant weakening of the axial (Co-N) bond, together with a 25-times higher basicity relative to Co(beta)-methylcobalamin (2). Methyl-transfer equilibria of pH-neutral aqueous solutions of K(2)-5 and cob(I)alamin (K-7) on one side, and of cob(I)alamin-(3''-->2'),(3''-->5')-bis-2''-deoxythymidyl-3''-ate (K(3)-8) and methylcobalamin (2) on the other, were studied at room temperature (Scheme 3). The NMR-derived data provided an equilibrium constant of ca. 0.3. Activation of K(2)-5 for abstraction of its Co-bound Me group by a nucleophile (such as cob(I)alamin) was, thus, indicated.
- Subjects :
- Aqueous solution
Molecular Structure
Stereochemistry
Chemistry
Bioengineering
DNA
General Chemistry
General Medicine
Methylation
Biochemistry
Vitamin B 12
chemistry.chemical_compound
Nucleophile
Covalent bond
Methylcobalamin
medicine
Molecular Medicine
Methyl donor
Molecular Biology
Equilibrium constant
medicine.drug
Conjugate
Subjects
Details
- ISSN :
- 16121872
- Volume :
- 2
- Database :
- OpenAIRE
- Journal :
- Chemistry & Biodiversity
- Accession number :
- edsair.doi.dedup.....b68561d54475e77b4cc5bd672b2f189b