RESUMEN
A beta-N-Acetylhexosaminidase (EC 3.2.1.52) was purified from hepatic extracts of Sotalia fluviatilis, order Cetacea. The protein was purified by using ammonium sulfate fractionation and four subsequent chromatographies (Biogel A 1.5 m, Chitin, Deae-Biogel and hydroxyapatite resins). After these purification steps, the enzyme was purified 380.5-fold with an 8.4% yield. The molecular mass (10 kDa) was estimated by SDS-PAGE and MALDI-TOF analysis. A Km of 2.72 mM and Vmax 9.5 x 10(-6) micromol/(min x mg) were found for this enzyme, determined by p-nitrophenyl-beta-D: -hexosaminide substrate digestion. Optimal pH and temperature for beta-N-Acetylhexosaminidase activity were 5.0 and 60 degrees C, respectively. Enzyme activity was inhibited by sodium selenate (Na(2)SeO(4)), mercuric chloride (HgCl(2)) and sodium dodecyl sulfate (C(12)H(25)SO(4)Na), and activated by zinc, calcium, barium and lithium ions. Characterization of the beta-N-Acetylhexosaminidase in Sotalia fluviatilis can be a basis for physiological studies in this species.
Asunto(s)
Delfines/metabolismo , Hígado/enzimología , beta-N-Acetilhexosaminidasas/aislamiento & purificación , Animales , Carbohidratos , Cromatografía en Gel , Electroforesis en Gel de Poliacrilamida , Concentración de Iones de Hidrógeno , Cinética , Hígado/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Temperatura , beta-N-Acetilhexosaminidasas/química , beta-N-Acetilhexosaminidasas/metabolismoRESUMEN
Bradykinin related peptides (BRPs) present in the water-soluble secretion and freshly dissected skin fragments of Phyllomedusa hypochondrialis were investigated by mass spectrometry techniques. Eighteen BRPs, along with their post-translational modifications, were characterized in the secretion by de novo MS/MS sequencing and direct MALDI imaging experiments of the frog skin. These molecules revealed strong sequence similarities to the main plasma kinin of some mammals and reptiles. Such a diversity of molecules, within the same peptide family, belonging to a single amphibian species may be related to functional specializations of these peptides and a variety of corresponding receptors that might be present in a number of different predators. Also, a novel analog, [Val]1,[Thr]6-bradykinyl-Gln,Ser had its biological activity positively detected in cell culture expressing the human bradykinin B2 receptor and in guinea pig ileum preparations.
Asunto(s)
Bradiquinina/análogos & derivados , Bradiquinina/química , Ranidae/metabolismo , Secuencia de Aminoácidos , Animales , Células CHO , Cricetinae , Cricetulus , Femenino , Cobayas , Humanos , Hidroxiprolina/química , Espectrometría de Masas , Datos de Secuencia Molecular , Músculo Liso/citología , Músculo Liso/metabolismo , Ranidae/clasificación , Receptor de Bradiquinina B2/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , TransfecciónRESUMEN
O vírus rábico foi isolado de morcego frugívoro Artibeus lituratus, capturado no município de Rio Claro, SP, em bairro residencial, em 1997. Neste município, o último caso de raiva animal ocorreu em 1986, sendo este o primeiro relato do isolamento em morcego frugívoro. As implicaçöes em Saúde Pública foram discutidas