Efficient enzymes for the synthesis and degradation of  glycosaminoglycans are important in natural biological systems of these glycoconjugates. In this respect, an understanding of the structures and functions of glycosidasys are of considerable importance for a better comprehension of their natural role. This work had the purpose of studies the enzyme involved in the metabolism of sulfated glycosaminoglycans in the mollusk Pomacea sp. The mollusk tissues were homogenized at 4°C. in a 0.1 M sodium acetate buffer, pH 5.0, then centrifuged at 8,000 x g. The proteins in the supernatant were submitted to fractioning with increasing concentrations of ammonium sulphate (0-50% and 50-80%) getting  the fractions F₁ and F₂, respectively, with the activity best visualized in the fraction F₂ (50-80%), results showed at eletroforesis in agarose gel in PDA buffer. A β- glucuronidase (F₃) was isolated by gel filtration chromatography (Bio-gel A - 1.5 m) of fraction F₂ on flow of 1ml/3min. High Performance Liquid Chromatography (HPLC) revealed only a protein band, confirming a 1.5% yield after 206 fold purification, with molecular mass of 116 kDa determined by electrophoresis in polyacrylamide gel with Sodium Dodecyl Sulfate (SDS). The determination of a number of kinetic parameters ideal for p-nitrophenyl-β-glucuronide catalysis by β- glucuronidase (F₃), exhibited optimal activity at pH 5.0 and temperature of 65°C for 6 hours, with an apparent K_m of 72 x 10^-2mM. A total of 1.2 µg of β-glucuronidase is needed for the degradation of 3mM p-N-β-glucuronide. BaCl₂ increased β-glucuronidase activity and the activity was completely inhibited by the compounds SDS and NaH₂PO₄.  Future studies on the three-dimensional structure and the aminoacid sequence will enable a deeper discussion of the inhibition and stimulation of some compounds in the β-glucuronidase activity of the mollusk Pomacea sp.

Financial supported:  CAPES