Purification and biosynthesis of quench spot, a drosopterin precursor in Drosophila melanogaster
Pteridine biosynthesis has been examined in extracts of the heads of Drosophila melanogaster by measuring the conversion of dihydroneopterin triphosphate to sepiapterin and the ''drosopterins'' (six eye pigments that are dipterin derivatives). These two products share a common first step in the production of an intermediate that is a branch point from which both products are formed. This first step can be catalyzed by sepiapterin synthase or by an enzyme found in particles that sediment at 600 g. A substance named ''quench spot'' was found earlier to be at low levels in the purple mutants that were defective in drosopterin synthesis and to be restored to normal when a suppressor mutant, su(s)/sup 2/, restored drosopterins in purple to normal levels. The sepia mutant is also deficient in the levels of both quench spot and drosopterins. In this report the authors propose that quench spot is a precursor of drosopterins, but not sepiapterin, and that it is formed from the sepiapterin synthase intermediate mentioned above. An additional precursor that is formed independently of the sepiapterin synthase pathway is also proposed that would react with quench spot to form drosopterins.
- Research Organization:
- Oak Ridge National Lab., TN
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 6350339
- Journal Information:
- Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 21:6; ISSN BICHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
AROMATICS
ARTHROPODS
AZAARENES
BIOCHEMICAL REACTION KINETICS
BIOSYNTHESIS
DIPTERA
DROSOPHILA
ENZYME ACTIVITY
ENZYMES
FLIES
FRUIT FLIES
HETEROCYCLIC COMPOUNDS
INSECTS
INVERTEBRATES
KINETICS
MUTATIONS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PRECURSOR
PTERIDINES
REACTION KINETICS
SYNTHESIS