Purification and properties of an α-galactosidase from Lenzites elegans

SAMPIETRO, D.A.; SGARIGLIA, M.A.; SOBERÓN, J.R.; VATTUONE, M.A.

Tafí del Valle - Tucumán - Argentina

Congreso; XXVIII Annual Scientific Meeting of Tucuman Biology Society; 2011

Tucuman Biology Society

Introduction: White rot fungi degrade hetero-1,4-β-D-xylans, hetero-1,4-β-D-mannans, galacto-glucomannans and glucomannans. Objectives: Purification of an α-galactosidase from L. elegans, and study of its physicochemical and kinetic properties. Materials and methods: Lenzites elegans isolated from decaying wood, was used. α-Galactosidase was isolated and purified from the culture medium. Results and discussion: The Mr of the enzyme was 158 kDa with two subunits (Mr = 61 kDa). The optimal temperature in the range 60-80°C. Optimal pH was 4.5; was stable from pH 3 to 7.5 after preincubation at 60 °C for 2 h. Is a glycoprotein active against α-D-galactopyranosides. Galactose is a non-competitive inhibitor (Ki = 22 mM vs. p-nitrophenyl-α-D-galactoside and 12 mM vs. α-D-melibiose as substrates). Glucose was a competitive inhibitor (Ki = 10 mM). Hg2+, Ag1+ and p-chloromercuribenzoate were inhibitors suggesting the presence of –SH groups in the active site. The N-terminal end (SPDTIVLDGTNFALN) suggests that it belongs to glycosyl hydrolase family 36.Conclusions: This fungus may become a useful source of α-galactosidase production for industrial use.