title: The salivary purine nucleosidase of the mosquito, Aedes aegypti.
abstract: A cDNA clone originating from adult female Aedes aegypti mosquitoes was found with substantial similarity to nucleosidases of the EC 3.2.2.1 enzyme class. Although this type of enzyme is unusual in animals, abundant enzyme activity was found in salivary homogenates of this mosquito, but not in salivary homogenates of the mosquitoes Anopheles gambiae and Culex quinquefasciatus, or the sand fly Lutzomyia longipalpis. Aedes salivary homogenate hydrolyses inosine and guanosine to hypoxanthine and xanthine plus the ribose moiety, but does not hydrolyse the pyrimidines uridine and cytidine, thus characterizing the presence of a purine nucleosidase activity. The enzyme is present in oil-induced saliva, indicating that it is secreted. Male Ae. aegypti salivary gland homogenates (SGH) have very low purine nucleosidase activity, suggesting that the enzyme plays a role in mosquito blood feeding. A novel isocratic HPLC method to separate nucleosides and their bases is described.
authors.affiliation: Section of Medical Entomology, Laboratory of Parasitic Diseases, Building 4, Room 126, 4 Center Drive, MSC 0425, NIH, MD 20892-0425, Bethesda, USA. jribeiro@nih.gov
authors.forename: José M C
authors.initials: JM
authors.lastname: Ribeiro
authors.forename: Jesus G
authors.initials: JG
authors.lastname: Valenzuela
mesh_terms: D000330:Aedes / Q000201:enzymology*; D000595:Amino Acid Sequence; D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D005260:Female; D007525:Isoelectric Focusing; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009699:N-Glycosyl Hydrolases / Q000737:chemistry / Q000378:metabolism*; D012463:Saliva / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid
chemical_list: D009699:N-Glycosyl Hydrolases; C030681:purine nucleosidase