
Isolation and characterization of a second molybdopterin dinucleotide: molybdopterin cytosine dinucleotide.
The pterin cofactor (bactopterin) in the molybdoenzyme CO dehydrogenase isolated from Pseudomonas carboxydoflava has previously been shown to differ from molybdopterin in molecular mass, phosphate content, stability, and other properties, implying a novel structure. The structure of the CO dehydrogenase pterin has been investigated in the present studies by alkylation and isolation of the carboxamidomethyl derivative. The alkylated pterin was identified as [di-(carboxamidomethyl)]molybdopterin cytosine dinucleotide on the basis of its absorption properties and by degradation with nucleotide pyrophosphatase yielding carboxamidomethylmolybdopterin and CMP. Further treatment of these products with alkaline phosphatase produced species with absorption and chromatographic properties identical to those of the corresponding dephospho compounds. Molybdopterin cytosine dinucleotide is the second molybdopterin variant to be structurally characterized. The fact that molybdopterin cytosine dinucleotide and molybdopterin guanine dinucleotide contain molybdopterin in their structure shows that the pterin moiety, with its unique dithiolene-containing sidechain, is a structural element which is common to the organic portion of the molybdenum cofactors of many molybdoenzymes.
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- Spectrophotometry, Ultraviolet
- Pterins
- Pseudomonas
- Multienzyme Complexes
- Molecular Structure
- Cytosine Nucleotides
- Chromatography, High Pressure Liquid
- Biochemistry & Molecular Biology
- Aldehyde Oxidoreductases
- 3101 Biochemistry and cell biology
Citation

Published In
DOI
ISSN
Publication Date
Volume
Issue
Start / End Page
Location
Related Subject Headings
- Spectrophotometry, Ultraviolet
- Pterins
- Pseudomonas
- Multienzyme Complexes
- Molecular Structure
- Cytosine Nucleotides
- Chromatography, High Pressure Liquid
- Biochemistry & Molecular Biology
- Aldehyde Oxidoreductases
- 3101 Biochemistry and cell biology