Ribeiro José M C, Valenzuela Jesus G
Section of Medical Entomology, Laboratory of Parasitic Diseases, Building 4, Room 126, 4 Center Drive, MSC 0425, NIH, MD 20892-0425, Bethesda, USA.
Insect Biochem Mol Biol. 2003 Jan;33(1):13-22. doi: 10.1016/s0965-1748(02)00078-4.
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.
从成年雌性埃及伊蚊中发现了一个cDNA克隆，它与EC 3.2.2.1酶类的核苷酶有显著相似性。尽管这类酶在动物中并不常见，但在这种蚊子的唾液匀浆中发现了丰富的酶活性，而在冈比亚按蚊、致倦库蚊的唾液匀浆以及长须罗蛉的唾液匀浆中未发现。埃及伊蚊唾液匀浆可将肌苷和鸟苷水解为次黄嘌呤和黄嘌呤以及核糖部分，但不水解嘧啶尿苷和胞苷，从而确定存在嘌呤核苷酶活性。该酶存在于油诱导的唾液中，表明它是分泌型的。雄性埃及伊蚊唾液腺匀浆（SGH）的嘌呤核苷酶活性非常低，这表明该酶在蚊子吸血过程中起作用。描述了一种用于分离核苷及其碱基的新型等度高效液相色谱方法。
