The structure of a molybdopterin precursor. Characterization of a stable, oxidized derivative.


Journal Article

An oxidized pterin species, termed compound Z, has been isolated from molybdenum cofactor-deficient mutants of Escherichia coli and shown to be the direct product of oxidation of a molybdopterin precursor which accumulates in these mutants. The complete structural characterization of compound Z has been accomplished. A carbonyl function at C-1' of the 6-alkyl side chain can be reacted with 2,4-dinitrophenylhydrazine to yield a phenylhydrazone and can be reduced with borohydride, producing a mixture of two enantiomers, each with a hydroxyl group on C-1'. Compound Z contains one phosphate/pterin and no sulfur. The phosphate group is insensitive to alkaline phosphatase and to a number of phosphodiesterases but is quantitatively released as inorganic phosphate by mild acid hydrolysis. From 31P and 1H NMR of compound Z it was inferred that the phosphate is bound to C-2' and C-4' of a 4-carbon side chain, forming a 6-membered cyclic structure. Mass spectral analysis showed an MH+ ion with an exact mass of 344.0401 corresponding to the molecular formula C10H11N5O7P, confirming the proposed structure.

Full Text

Duke Authors

Cited Authors

  • Johnson, JL; Wuebbens, MM; Rajagopalan, KV

Published Date

  • August 15, 1989

Published In

Volume / Issue

  • 264 / 23

Start / End Page

  • 13440 - 13447

PubMed ID

  • 2668266

Pubmed Central ID

  • 2668266

International Standard Serial Number (ISSN)

  • 0021-9258


  • eng

Conference Location

  • United States