+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Purification and properties of an unusual NADPH-dependent ketose reductase from the silverleaf whitefly



Purification and properties of an unusual NADPH-dependent ketose reductase from the silverleaf whitefly



Insect Biochemistry and Molecular Biology 28(5-6): 357-363



Sorbitol accumulates in the silverleaf whitefly when this insect is exposed to elevated temperatures. Synthesis of sorbitol in the silverleaf whitefly is catalyzed by an unconventional enzyme that converts fructose to sorbitol using NADPH as the coenzyme. In the present study, the NADPH-dependent ketose reductase from adult whiteflies was purified to apparent homogeneity and characterized. The NADPH-dependent ketose reductase was tetrameric, composed of 38.7 kD subunits, and catalyzed both fructose reduction and sorbitol oxidation. The purified whitefly enzyme exhibited an almost exclusive requirement for NADP(H) for ketose reduction/sorbitol oxidation. The pH and temperature optima for fructose reduction and sorbitol oxidation were 7 and 45degreeC and > 9 and 50degreeC, respectively. The affinity of the enzyme for fructose was very low, but physiological considering the high concentrations of carbohydrate available to this phloem-feeding insect. Edman degradation analysis of three peptides from the enzyme showed that their amino acid sequences matched internal sequences of NAD-dependent sorbitol dehydrogenases. Thus, the NADPH-dependent ketose reductase responsible for sorbitol synthesis in the silverleaf whitefly is structurally similar to the sorbitol catabolic enzyme NAD+-dependent sorbitol dehydrogenase, but differs in its coenzyme requirement. Antibodies directed against the purified whitefly enzyme showed that this novel ketose reductase occurs in whitefly eggs and nymphs, as well as in the adults.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 003247145

Download citation: RISBibTeXText

DOI: 10.1016/s0965-1748(98)00005-8


Related references

Vitamin K3-dependent NADPH oxidase of liver microsomes. Purification, properties, and identity with microsomal NADPH-cytochrome c reductase. Journal of Biochemistry 67(2): 199-210, 1970

Purification and properties of an NADPH-dependent carbonyl reductase from human brain. Relationship to prostaglandin 9-ketoreductase and xenobiotic ketone reductase. Journal of Biological Chemistry 256(3): 1206-1213, 1981

Purification and characterization of a novel NADPH(NADH)-dependent glyoxylate reductase from spinach leaves. Comparison of immunological properties of leaf glyoxylate reductase and hydroxypyruvate reductase. Biochemical Journal 239(3): 653-659, 1986

Purification and properties of an NADPH-dependent 21-oxo-20-hydroxysteroid reductase (17beta-aldol reductase) from sheep liver. Isolation of the 20beta-glycol product. Journal of Biological Chemistry 253(7): 2126-2131, 1978

Purification and characterization of a novel nadph nadh dependent glyoxylate reductase from spinach spinacia oleracea leaves comparison of immunological properties of leaf glyoxylate reductase and hydroxypyruvate reductase. Biochemical Journal 239(3): 653-660, 1986

Purification and properties of NADPH-dependent tylosin reductase from Streptomyces fradiae. Journal of Biological Chemistry 268(25): 18987-18993, 1993

Purification and properties of an NADPH-dependent dihydroxyacetone reductase from Phycomyces spores. FEMS microbiology letters Federation of European Microbiological Societies 30(3): 377-381, 1985

Purification and properties of NADPH-dependent aldehyde reductase from human liver. Journal of Biological Chemistry 252(11): 3821-3828, 1977

Purification and properties of an nadph dependent dihydroxyacetone reductase from phycomyces blakesleeanus spores. FEMS Microbiology Letters 30(3): 377-382, 1985

Purification and some properties of nadph dependent cytochrome c reductase from sheep liver microsomes. DOGA Bilim Dergisi Seri C Tip 9(3): 287-303, 1985

Purification and some properties of a hepatic NADPH-dependent reductase that specifically acts on 1,5-anhydro-D-fructose. Journal of Biochemistry 123(1): 189-193, 1998

Purification and properties of a NADPH-dependent erythrose reductase from the newly isolated Torula corallina. Biotechnology Progress 19(2): 495-500, 2003

NADPH-dependent GMP reductase isoenzyme of human (GMPR2). Expression, purification, and kinetic properties. International Journal of Biochemistry and Cell Biology 34(9): 1035-1050, 2002

Purification and properties of an unusual UDP-glucose dehydrogenase, NADPH-dependent, from Xanthomonas albilineans. Microbiological Research 163(3): 362-371, 2008

Studies on the metabolism of unsaturated fatty acids. XIV. Purification and properties of NADPH-dependent trans-2-enoyl-CoA reductase of Escherichia coli K-12. Journal of Biochemistry 95(5): 1315-1321, 1984