RESUMO
Cytosolic sulfotransferases are enzymes that catalyze the conjugation of sulfate groups to a variety of xenobiotic and endogenous substrates. A mutation in the SULT1A1 gene has been associated with decreased sulfotransferase activity. We studied 125 cancer patients and 100 healthy controls from Brazil matched by age and gender. The objective of this study was to assess the impact of the SULT1A1 polymorphism on sulfotransferase activity in a population of cancer patients. Both heterozygous and homozygous individuals for the mutant allele had significantly decreased sulfotransferase enzymatic activity. This decrease was more significant in cancer patients. The frequency of the SULT1A1( *)2 allele was increased in the myeloma group (odds ratio=0.53). These data suggest a functional role for the SULT1A1 gene polymorphism in cancer.
Assuntos
Arilsulfotransferase/genética , Neoplasias/genética , Polimorfismo Genético , Adulto , Idoso , Arilsulfotransferase/metabolismo , Feminino , Frequência do Gene , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/enzimologia , Análise de Sequência de DNARESUMO
A beta-glucuronidase was purified from Pomacea sp. eggs by ammonium sulfate fractionation, DEAE-BioGel and Heparin-Sepharose chromatographies. This enzyme showed a Mr 180 kDa, with subunits of 90 kDa. The kinetic parameters were: pH 4.0, temperature 60 degrees C, Km 2.7 x 10(-6) and Vmax 15.3 microM/h, activator Mg+2, and inhibitor: lactone of D-saccharic acid. beta-glucuronidase is an exoglucuronidase involved in glycosaminoglycans metabolism with kinetics parameters similar to those found in mammals.