title: Lutzomyia longipalpis: pH in the gut, digestive glycosidases, and some speculations upon Leishmania development.
abstract: Screening for digestive glycosidases in different parts of the gut and associated organs of Lutzomyia longipalpis is reported. Searches for the enzymes were made in blood-fed and non-blood-fed females and the enzymes were characterized as soluble or membrane-bound molecules. A total of four different activities were detected, corresponding to the following specificities: an alpha-glucosidase, an N-acetyl-beta-d-glucosaminidase, an N-acetyl-beta-d-galactosaminidase, and an alpha-l-fucosidase. Their possible role and importance for Leishmania development are discussed and the alpha-glucosidase enzyme was partially characterized. The pH inside the gut of non-blood-fed phlebotomines was measured with pH indicator dyes. The pH ranges obtained for crop, midgut, and hindgut were, respectively, higher than pH 6, pH 6, and lower than pH 6. A hypothesis concerning these data and Leishmania development is proposed.
authors.affiliation: Departamento de Parasitologia, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais-UFMG, Caixa Postal 486, Minas Gerais, Belo Horizonte, CEP 31 270-901, Brazil. nelder@icb.ufmg.br
authors.forename: N F
authors.initials: NF
authors.lastname: Gontijo
authors.forename: S
authors.initials: S
authors.lastname: Almeida-Silva
authors.forename: F F
authors.initials: FF
authors.lastname: Costa
authors.forename: M L
authors.initials: ML
authors.lastname: Mares-Guia
authors.forename: P
authors.initials: P
authors.lastname: Williams
authors.forename: M N
authors.initials: MN
authors.lastname: Melo
mesh_terms: D000818:Animals; D050260:Carbohydrate Metabolism; D004063:Digestion; D005260:Female; D006026:Glycoside Hydrolases / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007303:Insect Vectors / Q000737:chemistry / Q000201:enzymology* / Q000469:parasitology; D007891:Leishmania / Q000254:growth & development*; D009596:Nitrophenols / Q000737:chemistry; D011576:Psychodidae / Q000737:chemistry / Q000201:enzymology* / Q000469:parasitology; D012995:Solubility; D013379:Substrate Specificity
chemical_list: D009596:Nitrophenols; D006026:Glycoside Hydrolases; C024836:4-nitrophenol