1. Transferase Activity of Lactobacillal and Bifidobacterial β-Galactosidases with Various Sugars as Galactosyl Acceptors.
- Author
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Arreola SL, Intanon M, Wongputtisin P, Kosma P, Haltrich D, and Nguyen TH
- Subjects
- Acetylgalactosamine analogs & derivatives, Acetylgalactosamine metabolism, Acetylgalactosamine pharmacokinetics, Acetylglucosamine metabolism, Acetylglucosamine pharmacokinetics, Bifidobacterium metabolism, Galactosamine metabolism, Glucosamine metabolism, Glucose metabolism, Limosilactobacillus reuteri metabolism, Substrate Specificity, Galactose metabolism, Lactobacillus enzymology, Lactose metabolism, Oligosaccharides metabolism, Transferases metabolism, beta-Galactosidase metabolism
- Abstract
The β-galactosidases from Lactobacillus reuteri L103 (Lreuβgal), Lactobacillus delbrueckii subsp. bulgaricus DSM 20081 (Lbulβgal), and Bifidobacterium breve DSM 20281 (Bbreβgal-I and Bbreβgal-II) were investigated in detail with respect to their propensity to transfer galactosyl moieties onto lactose, its hydrolysis products D-glucose and D-galactose, and certain sugar acceptors such as N-acetyl-D-glucosamine (GlcNAc), N-acetyl-D-galactosamine (GalNAc), and L-fucose (Fuc) under defined, initial velocity conditions. The rate constants or partitioning ratios (kNu/kwater) determined for these different acceptors (termed nucleophiles, Nu) were used as a measure for the ability of a certain substance to act as a galactosyl acceptor of these β-galactosidases. When using Lbulβgal or Bbreβgal-II, the galactosyl transfer to GlcNAc was 6 and 10 times higher than that to lactose, respectively. With lactose and GlcNAc used in equimolar substrate concentrations, Lbulβgal and Bbreβgal-II catalyzed the formation of N-acetyl-allolactosamine with the highest yields of 41 and 24%, respectively, as calculated from the initial GlcNAc concentration.
- Published
- 2016
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