Extracellular alpha-galactosidase from Debaryomyces hansenii UFV-1 and its use in the hydrolysis of raffinose oligosaccharides.
Raffinose oligosaccharides (RO) are the factors primarily responsible for flatulence upon ingestion of soybean-derived products. ROs are hydrolyzed by alpha-galactosidases that cleave alpha-1,6-linkages of alpha-galactoside residues. The objectives of this study were the purification and characterization of extracellular alpha-galactosidase from Debaryomyces hansenii UFV-1. The enzyme purified by gel filtration and anion exchange chromatographies presented an Mr value of 60 kDa and the N-terminal amino acid sequence YENGLNLVPQMGWN. The Km values for hydrolysis of pNP alphaGal, melibiose, stachyose, and raffinose were 0.30, 2.01, 9.66, and 16 mM, respectively. The alpha-galactosidase presented absolute specificity for galactose in the alpha-position, hydrolyzing pNPGal, stachyose, raffinose, melibiose, and polymers. The enzyme was noncompetitively inhibited by galactose (Ki = 2.7 mM) and melibiose (Ki = 1.2 mM). Enzyme treatments of soy milk for 4 h at 60 degrees C reduced the amounts of stachyose and raffinose by 100%.
BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG, 36570-000, Brazil.
Pollyanna A
PA
Viana
Sebastião T
ST
de Rezende
Virgínia M
VM
Marques
Larissa M
LM
Trevizano
Flávia M L
FM
Passos
Maria G A
MG
Oliveira
Marcelo P
MP
Bemquerer
Jamil S
JS
Oliveira
Valéria M
VM
Guimarães
D000595:Amino Acid Sequence; D001203:Ascomycota / Q000201:enzymology*; D005414:Flatulence; D006868:Hydrolysis; D009844:Oligosaccharides / Q000032:analysis / Q000378:metabolism*; D011887:Raffinose / Q000032:analysis / Q000378:metabolism*; D045730:Soy Foods; D041942:Soy Milk / Q000737:chemistry; D000519:alpha-Galactosidase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
D009844:Oligosaccharides; C005695:stachyose; D000519:alpha-Galactosidase; D011887:Raffinose