The mechanism of action of alpha-amylase from Lactobacillus fermentum on maltooligosaccharides.
The action pattern of Lactobacillus fermentum alpha-amylase (FERMENTA) was examined using a series of maltooligosaccharides (G2-G7) as substrates. Structurally, this enzyme has a molecular mass (106 kDa) almost twofold higher than alpha-amylases from mammalians and cereals. The product pattern was investigated through an analysis of products and substrates using HPAEC with pulsed amperometric detection. FERMENTA was consistent with an endo-type of amylase. The bond cleavage frequencies were studied using maltooligosaccharides of various chain lengths as substrate, i.e. maltose up to maltoheptaose and DP 4900-amylose catalyzed by FERMENTA. The catalytic efficiency (k(cat)/K(m)) increased with chain length from maltose (8.7 x 10(4) M(-1) s(-1)) up to amylose (1 x10(9) M(-1) s(-1)). These action pattern results revealed that FERMENTA can readily cleave the third linkage from the reducing end of the maltooligosaccharides (G5-G7).
Institut de Recherche pour le Développement, UMR 141, 911 av. d'Agropolis, BP 64501, 34394 Montpellier, Cedex 5, France. talamond@mpl.ird.fr
Pascale
P
Talamond
Michel
M
Noirot
Alexandre
A
de Kochko
D000688:Amylose / Q000378:metabolism; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004563:Electrochemistry; D006868:Hydrolysis; D052197:Limosilactobacillus fermentum / Q000201:enzymology*; D009844:Oligosaccharides / Q000378:metabolism*; D000516:alpha-Amylases / Q000378:metabolism*
D009844:Oligosaccharides; C021705:maltooligosaccharides; D000688:Amylose; D000516:alpha-Amylases