13319-33-0Relevant articles and documents
Efficient chemoenzymatic synthesis of lipo-chitin oligosaccharides as plant growth promoters
Chambon,Despras,Brossay,Vauzeilles,Urban,Beau,Armand,Cottaz,Fort
, p. 3923 - 3930 (2015)
Lipo-chitin oligosaccharides (Nod and Myc LCOs) are molecules involved in symbiotic phenomena in the plant kingdom. They play a major role in the process of atmospheric nitrogen fixation and mineral soil nutrients uptake both in legumes and in non-legumes, and are active at extremely low concentrations down to the nano- and even picomolar range. These compounds contain various substitutions along the oligosaccharide backbone of the molecule including an essential fatty acid on the non-reducing unit and are considered as environmentally-friendly fertilizers. Currently, chemical synthesis cannot produce precursors of Nod and Myc LCOs at a large scale and an in vitro chemoenzymatic pathway is presented here as a new and efficient method for preparing quantities of these high-value oligosaccharides. VC1280 (Vibrio cholerae) is a chitin deacetylase (CD) capable of regioselectively cleaving an acetate from the non-reducing penultimate N-acetyl-d-glucosaminyl (GlcNAc) unit of chitin oligosaccharides (COs). This provides a free amino group which can be further N-acylated with a fatty-acid chain to give analogues of LCOs. Alternatively, the non-reducing GlcNAc unit can be removed by β-N-acetylglucosaminidase treatment, followed by N-acylation to give natural LCOs. VC1280 CD was produced in the periplasm of E. coli. Under the conditions used, 120 mg of the pure enzyme was recovered from 1 L of culture medium. For the first time, in vitro production of a library of natural LCOs as well as their analogues has been carried out at a preparative scale from biosourced chitin oligosaccharides constituting an approach of major interest for sustainable agriculture.
A glycosynthase derived from an inverting GH19 chitinase from the moss Bryum coronatum
Ohnuma, Takayuki,Fukuda, Tatsuya,Dozen, Satoshi,Honda, Yuji,Kitaoka, Motomitsu,Fukamizo, Tamo
, p. 437 - 443 (2012/09/25)
BcChi-A, a GH19 chitinase from the moss Bryum coronatum, is an endo-acting enzyme that hydrolyses the glycosidic bonds of chitin, (GlcNAc)n [a β-1,4-linked polysaccharide of GlcNAc (N-acetylglucosamine) with a polymerization degree of n], through an inverting mechanism. When the wild-type enzyme was incubated with α-(GlcNAc)2-F [α-(GlcNAc) 2 fluoride] in the absence or presence of (GlcNAc)2, (GlcNAc)2 and hydrogen fluoride were found to be produced through the Hehre resynthesis-hydrolysis mechanism. To convert BcChi-A into a glycosynthase, we employed the strategy reported by Honda et al. [(2006) J. Biol. Chem. 281, 1426-1431; (2008) Glycobiology 18, 325-330] of mutating Ser102, which holds a nucleophilic water molecule, and Glu 70, which acts as a catalytic base, producing S102A, S102C, S102D, S102G, S102H, S102T, E70G and E70Q. In all of the mutated enzymes, except S102T, hydrolytic activity towards (GlcNAc)6 was not detected under the conditions we used. Among the inactive BcChi-A mutants, S102A, S102C, S102G and E70G were found to successfully synthesize (GlcNAc)4 as amajor product from α-(GlcNAc)2-F in the presence of (GlcNAc) 2. The S102A mutant showed the greatest glycosynthase activity owing to its enhanced F- releasing activity and its suppressed hydrolytic activity. This is the first report on a glycosynthase that employs amino sugar fluoride as a donor substrate. The Authors Journal compilation
Enzymatic synthesis of 3-O-methylated chitin oligomers from new derivatives of a chitobiose oxazoline
Sakamoto, Junji,Kobayashi, Shiro
, p. 698 - 699 (2007/10/03)
Regiospecifically 3-O- and/or 3′-O-methylated derivatives of a chitobiose oxazoline have been synthesized as new substrate monomers and subjected to a chitinase catalysis, leading to the first synthesis of 3-O-methylated chitin oligomers via enzymatic oligomerization. (Graph Presented).