Biosynthesis of drosopterins by an enzyme system from Drosophila melanogaster

Journal Article · Mon Jan 01 00:00:00 EST 1979 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00579a025· OSTI ID:5835201

Dorsett, D; Yim, J J; Jacobson, K B

The red eye pigment of Drosophila melanogaster consists of six complex pteridines known as neodrosopterin, drosopterin, isodrosopterin, fraction e, and aurodrosopterins; these pigments are greatly reduced in the purple mutant. Conditions for biosynthesis of these drosopterins are described and compared with those for the synthesis of sepiapterin. The enzymes are contained in a soluble, pteridine-free extract obtained between 40 and 60% saturated ammonium sulfate. The results indicate that sepiapterin synthase consists of two enzymes, the first of which provides a precursor for drosopterin biosynthesis. The evidence is (1) the purple mutant, low in accumulated sepiapterin and drosopterins, is known to have about 10% of the sepiapterin synthase activity of wild type; (2) unlabeled sepiapterin does not cause isotope dilution of drosopterin synthesis; (3) the 600g pellet prepared from a wild-type head homogenate contains drosopterin synthesizing activity and no sepiapterin synthase, yet a heat-labile factor in this fraction stimulates sepiapterin synthesis in the 100,000 g supernatant of wild-type or pr flies; (4) sepiapterin and drosopterin syntheses require Mg/sup 2 +/; (5) sepiapterin synthesis is stimulated by NADPH; drosopterin synthesis responds to either NADPH or NADH. Although drosopterins are complex pteridine-type pigments, we have demonstrated their biosynthesis by soluble enzymes. This allows us to consider investigation into the mechanism by which the amounts of these pigments are regulated.

• Research Organization: Oak Ridge National Lab., TN
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5835201
• Journal Information: Biochemistry; (United States), Vol. 18:12
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
EYES
PIGMENTS
PTERIDINES
BIOSYNTHESIS
ENZYMES
AMMONIUM SULFATES
DROSOPHILA
MAGNESIUM
NAD
NADP
ALKALINE EARTH METALS
AMMONIUM COMPOUNDS
ANIMALS
ARTHROPODS
BODY
COENZYMES
ELEMENTS
FLIES
FRUIT FLIES
HETEROCYCLIC COMPOUNDS
INSECTS
INVERTEBRATES
METALS
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
SENSE ORGANS
SULFATES
SULFUR COMPOUNDS
SYNTHESIS
550200* - Biochemistry