Highly efficient and regioselective enzymatic synthesis of β-(1→3) galactosides in biosolvents

Abstract

Highly efficient and regioselective enzymatic synthesis of b-(1A3) galactosides in biosolvents3

Enzymatic synthesis of novel fructosylated compounds by Ffase from Schwanniomyces occidentalis in green solvents

“…On the contrary, GCL12 and TROMA-Tf2N caused a shi of the maximum emission wavelength towards the blue, from 326 nm to 320 nm, suggesting an increased packing of the tryptophan groups into the internal non-polar environment of the protein and thus higher integrity and maintenance of enzyme structure and activity. 28,30 This circumstance may be particularly relevant for Ffase as it has two tryptophan residues (Trp-76 and Trp-314) in its active center involved in the recognition of fructose moiety. 3 In addition, Ffase contains almost 47% of hydrophobic amino acids (with $83% aliphatic index), 3 which could be a determining factor for explaining its better stability in non-polar environments.…”

“…Reactions (500 mL) contained 10 U mL À1 -standard b-fructofuranosidase activity, 200 g L À1 sucrose in 0.2 M sodium acetate buffer pH 5.5, and 30% (v/v) nal concentration of solvents, except for GCL and DMA at 2 M. 28,55,56 Spain). Data obtained aer 65 min total analysis time were processed by Borwin soware (v. 1.5; Jasco Inc.).…”

β-N-Acetylhexosaminidases for Carbohydrate Synthesis via Trans-Glycosylation

“…However, whereas other hydrolytic enzymes such as proteases, esterases, or lipases can cope with even non-aqueous systems (a w < 0.01), it appears that glycosidases require at least a w ≥ 0.9 to be active [129]. Nevertheless, lowering of a w has been applied for many GHs to increase their trans-glycosylation efficiency [129][130][131][132][133][134][135][136], including GH20 hexosaminidases [21,24,46,54,56,61,62,73,87,88,[90][91][92][95][96][97]100,101,[103][104][105][106]115,116,[118][119][120].…”

Characterization of a Galactosynthase Derived from Bacillus circulans β‐Galactosidase: Facile Synthesis of D‐Lacto‐ and D‐Galacto‐N‐bioside

“…Because of the relatively simple and mild reaction conditions and the high stereospecificity of the glycosidic bonds, enzymatic synthesis has been considered as an alternative to conventional chemical methods. [9] In addition, coupled enzyme systems that used d-galactosyl-b-(1,3)-N-acetyl-d-hexosamine phosphorylase with enzymes that supply galactosyl-1-phosphate as the donor produced LNB and GNB with yields above 90 %. b-Galactosidase-catalyzed transglycosylations yield galacto-oligosaccharides containing usually b-1,4 or b-1,6 (but occasionally b-1,3) linkages.…”

“…[7,8] Several successful attempts, with ionic liquid as the co-solvent to improve the yields of the reactions catalyzed by wild-type (WT) BgaC, resulted in accumulation of transfer products in the reaction mixtures, with high yields because of the low hydrolysis of the products. [9] In addition, coupled enzyme systems that used d-galactosyl-b-(1,3)-N-acetyl-d-hexosamine phosphorylase with enzymes that supply galactosyl-1-phosphate as the donor produced LNB and GNB with yields above 90 %. [10] Despite the high efficiency of these enzymatic methods, there are still limitations, such as the high cost of the ionic liquids, the requirement for an expensive cofactor (adenosine triphosphate) for the kinase reaction, and different optimal conditions for each of the individual enzymes used in the coupled-enzyme system.…”