RESUMO
Embryos of sea urchin Strongylocentrotus intermedius have been revealed to contain o-glycosylhydrolases: highly active 1,3-beta-D-glucanase and alpha-D-mannosidase as well as a lower activity of beta-D-glucosidase and beta-D-galactosidase. Dynamics of changes of the enzyme activities has been studied at various stages of the sea urchin embryo development. There also have been studied effects of some substances (natural fucoidans, beta-1,3; 1,6-glucans formed by enzymatic synthesis as well as a protein inhibitor of marine mollusc endo-1,3-beta-D-glucanases) on development of the embryos and biosynthesis of 1,3-beta-D-glucanase and alpha-D-mannosidase.
Assuntos
Embrião não Mamífero/enzimologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Regulação Enzimológica da Expressão Gênica/fisiologia , Glicosídeo Hidrolases/biossíntese , Strongylocentrotus/enzimologia , Animais , Embrião não Mamífero/embriologia , Strongylocentrotus/embriologia , Especificidade por Substrato/fisiologiaRESUMO
The ability to produce extracellular O-glycosylhydrolases was studied in 14 strains of marine filamentous fungi sampled from bottom sediments of the South China Sea. The following activities were detected in the culture liquids of the fungi: N-acetyl-D-glucosaminidase, D-glucosidase, D-galactosidase, beta-1,3-glucanase, amylase, and pustulanase. beta-1,3-Glucanases were isolated by ultrafiltration, hydrophobic interaction chromatography, and ion-exchange chromatography, and their properties were studied. Data on products of enzymatic digestion of laminaran, absence of transglycosylation activity, and the pattern of action of natural inhibitors confirmed that beta-1,3-glucanase belonged to the exo type. Inhibitor analysis demonstrated the role of a thiol group and tryptophan and tyrosine residues in the catalytic activity.
Assuntos
Glucana 1,3-beta-Glucosidase/metabolismo , Trichoderma/enzimologia , Cromatografia por Troca Iônica , Meios de Cultivo Condicionados , Estabilidade Enzimática , Sedimentos Geológicos/microbiologia , Glucana 1,3-beta-Glucosidase/antagonistas & inibidores , Glucana 1,3-beta-Glucosidase/isolamento & purificação , Glucanos , Concentração de Íons de Hidrogênio , Biologia Marinha , Polissacarídeos/metabolismo , Federação Russa , Especificidade da Espécie , Compostos de Sulfidrila/análise , Temperatura , Trichoderma/crescimento & desenvolvimento , Triptofano/análise , Tirosina/análise , UltrafiltraçãoRESUMO
Ninety fungal strains (42 species) isolated from marine habitats were studied for their ability to produce extracellular enzymes. Cultural filtrates of these strains were shown to contain a series of glycosidases (beta-glucosidases, N-acetyl-beta-glucosaminidases, beta-galactosidases alpha-mannosidases) and glucanases (1,3-beta-glucanases, amylases) which varied with habitat. The level of activity depended on the species of fungi. Several promising strains capable of producing both individual enzymes and a set of enzymes for splitting carbohydrate-containing compound have been isolated. Optimal conditions for growth of Chaetomium indicum and for biosynthesis of beta-1,3-glucanase were determined. beta-1,3-Glucanase was isolated using ion-exchange chromatography, ultrafiltration, and gel filtration. The presence of 2 enzyme forms was shown; both forms were exo-beta-1,3-glucanases.