47491-70-3Relevant academic research and scientific papers
Sustainable synthesis of N-acetyllactosamine using an immobilized β-galactosidase on a tailor made porous polymer
Aires-Trapote, Antonio,Tamayo, Aitana,Rubio, Juan,Rumbero, Angel,Hernáiz, María J.
, p. 40375 - 40383 (2015/05/20)
Porous polymer particles containing surface epoxy groups were synthesized for immobilizing β-galactosidase from Bacillus circulans. Enzyme immobilization was achieved by covalent attachment to a custom made porous polymer and the biocatalyst was character
Optimised N-acetyl-D-lactosamine synthesis using Thermus thermophilus β-galactosidase in bio-solvents
Sandoval, Manuel,Civera, Concepción,Berenguer, José,García-Blanco, Francisco,Hernaiz, María J.
, p. 1148 - 1152 (2013/02/25)
Synthesis of N-acetyl-D-lactosamine (Gal-β[1→4]GlcNAc, LacNAc) catalyzed by β-galactosidase from Thermus thermophilus (TTP0042) is affected by side reactions that give as result very low yields (about 20%) of LAcNAc when the reaction is performed in buffer. The process is improved (up to 91% of disaccharide yield) when the reaction takes place in the presence of solvents from biomass (bio-solvents) at 2.0 M concentration. Most of the solvents tested increased the LacNAc synthesis and reduced the undesired side reactions. In order to understand the possible effects of these solvents over the enzyme regioselectivity, we developed a conformational study of the enzyme structure in the presence of a selected bio-solvent by circular dichroism and fluorescence. According to this study, we were able to conclude that the presence of bio-solvents in the reaction media modifies the enzyme secondary and tertiary structure and this may be the cause of the regioselectivity changes observed in the transglycosylation reaction.
Solvents derived from glycerol modify classical regioselectivity in the enzymatic synthesis of disaccharides with Biolacta β-galactosidase
Perez-Sanchez, Maria,Sandoval, Manuel,Cortes-Cabrera, Alvaro,Garcia-Marin, Hector,Sinisterra, Jose V.,Garcia, Jose I.,Hernaiz, Maria J.
experimental part, p. 2810 - 2817 (2011/12/05)
Green solvents made from glycerol change the classical regioselectivity of Biolacta No 5 β-galactosidase, from β(1→4) to β(1→6) linkages when a 2 M concentration was used. In order to explain these results, the non-proteic compounds present in
Characterization of a novel Salmonella Typhimurium chitinase which hydrolyzes chitin, chitooligosaccharides and an N-acetyllactosamine conjugate
Larsen, Tanja,Petersen, Bent O.,Storgaard, Birgit G.,Duus, Jens,Palcic, Monica M.,Leisner, Jorgen J.
scheme or table, p. 426 - 436 (2012/01/13)
Salmonella contain genes annotated as chitinases; however, their chitinolytic activities have never been verified. We now demonstrate such an activity for a chitinase assigned to glycoside hydrolase family 18 encoded by the SL0018 (chiA) gene in Salmonella enterica Typhimurium SL1344. A C-terminal truncated form of chiA lacking a putative chitin-binding domain was amplified by PCR, cloned and expressed in Escherichia coli BL21 (DE3) with an N-terminal (His)6 tag. The purified enzyme hydrolyzes 4-nitrophenyl N,N′-diacetyl - d-chitobioside, 4-nitrophenyl -d-N,N′,N″-triacetylchitotriose and carboxymethyl chitin Remazol Brilliant Violet but does not act on 4-nitrophenyl N-acetyl - d-glucosaminide, peptidoglycan or 4-nitrophenyl -d-cellobioside. Enzyme activity was also characterized by directly monitoring product formation using 1H-nuclear magnetic resonance which showed that chitin is a substrate with the release of N,N′-diacetylchitobiose. Hydrolysis occurs with the retention of configuration and the enzyme acts on only the -anomers of chitooligosaccharide substrates. The enzyme also released N-acetyllactosamine disaccharide from Gal1 → 4GlcNAc-O-(CH2)8CONH(CH 2)2NHCO-tetramethylrhodamine, a model substrate for LacNAc terminating glycoproteins and glycolipids.
The efficient enzymatic synthesis of N-acetyllactosamine in an organic co-solvent
Yoon, Jung Hae,Rhee, Joon Shick
, p. 377 - 383 (2007/10/03)
In the presence of β-galactosidase from Bifidobacterium bifidum, N-acetyllactosamine was synthesized in significantly enhanced yield compared with earlier routes. Different proportions of the (1→4)- and (1→6)-linked forms were obtained depending on the choice of enzyme and reaction conditions, viz. the nature of added organic co-solvent (20-80% of 2-ethoxy ethyl ether, trimethyl phosphate, or acetone). The β-(1→4)-linked disaccharide was the major product and the β-(1→6)-linked disaccharide was the minor product. With β-galactosidases from P. multicolor, A. oryzae, B. longum the β-(1→6) linkage was exclusively synthesized. Procedures for optimising the yield of N-acetyllactosamine are discussed. An immobilized enzyme on a nylon powder column was used for the efficient recycling of enzyme and synthesizing the disaccharide. Copyright (C) 2000 Elsevier Science Ltd.
On the effect of the aglycon structure of three aryl β-D-galactosides on the yield and the regioselecttvity of the transglycolytic synthesis of N-acetyllactosamine
Vetere, Amedeo,Novelli, Lara,Paoletti, Sergio
, p. 515 - 521 (2007/10/03)
We examined the effect as donors of three aryl β-D-galactosides (i.e. p-nitrophenyl β-D-galactopyranoside, o-nitrophenyl β-D-galactopyranoside and phenyl β-D-galactopyranoside) on the regioselectivity and the yield of the synthesis of N-acetyllactosamine obtained from the transglycosylation reaction catalyzed by a crude preparation of β-D-galactosidase from Bacillus circulans at 25°C, 37°C and 55°C, respectively. Using p-nitrophenyl β-D-galactopyranoside the reaction results were fully regiospecific at all the temperatures considered: the maximum molar yield (74%) was obtained at an incubation temperature of 55°C Using o-nitrophenyl β-D-galactopyranoside as the donor the reaction was still highly regioselective and the maximum molar yield (50%) was achieved at an incubation temperature also of 55°C. Using phenyl β-D-galactopyranoside transglycolytic products appear only at an incubation temperature of 55°C but at very low molar yield (about 14%) and lower regioselectivity.
Chemical and enzymatic synthesis of glycoconjugates 2. High yielding regioselective synthesis of N-acetyllactosamine by use of recombinant thermophilic glycosidases library
Li, Jun,Wang, Peng G.
, p. 7967 - 7970 (2007/10/03)
β-Galactosidase activities from the recombinant thermophilic CLONEZYME(TM) glycosidase library were screened at 70°C for catalysis of a transgalactosylation from o-nitrophenyl-β-galactopyranoside to N-acetylglucosamine. Three thermophilic glycosidases (Gly001-06, -07 and -09) were found to produce predominantly the β(1-4)-linked isomer, Gal β(1-4)GlcNAc with up to 61% yield and less than 10% of the hydrolysis side reaction product. Thus, commercial recombinant thermophilic enzyme libraries constitute a novel class of biocatalysts for preparative organic synthesis.
ENZYMIC SYNTHESIS OF DISACCHARIDES BY USE OF THE REVERSED HYDROLYSIS ACTIVITY OF β-D-GALACTOSIDASES
Ajisaka, Katsumi,Fujimoto, Hiroshi,Nishida, Hiroko
, p. 35 - 42 (2007/10/02)
D-Galactosyl disaccharides have been synthesized by utilizing the reversed hydrolysis activity of β-D-galactosidases from E. coli and from A. oryzae, respectively.In order to shift the equilibrium towards the formation of disaccharide, solutions of monosaccharides were circulated through columns of immobilized β-D-galactosidase and activated carbon in series.After 24 h, the disaccharides were eluted with aqueous 50 percent ethanol from the column of activated carbon and analyzed by h.p.l.c. and 13C-n.m.r. spectroscopy.In this way, β-D-galactosyl-D-glucose, β-D-galactosyl-2-acetamido-2-deoxy-D-glucose, and β-D-galactosyl-D-fructose were produced in yields of 6.0, 16.0, and 11.3 percent, respectively, when the immobilized β-D-galactosidase from E. coli was used.The possible mechanism of the synthesis of the disaccharides is discussed.
