Search PubMed for references concerning: Me-GlcA-pNP
Title: Expression and characterization of two glucuronoyl esterases from Thielavia terrestris and their application in enzymatic hydrolysis of corn bran Tang J, Long L, Cao Y, Ding S Ref: Applied Microbiology & Biotechnology, 103:3037, 2019 : PubMed
The thermophilic fungus Thielavia terrestris when cultured on cellulose produces a cocktail of thermal hydrolases with potential application in saccharification of lignocellulosic biomass and other biotechnological areas. Glucuronoyl esterases are considered to play a unique role as accessory enzymes in lignocellulosic material biodegradation by cleaving the covalent ester linkage between 4-O-methyl-D-glucuronic acid (MeGlcA) and lignin in lignin-carbohydrate complexes (LCCs). Two glucuronoyl esterases from T. terrestris named TtGE1 and TtGE2 were expressed in Pichia pastoris. Both esterases displayed features of thermophilic enzymes, with the optimal temperature at 45 degrees C and 55 degrees C. TtGE1 and TtGE2 exhibited activity towards methyl (4-nitrophenyl beta-D-glucopyranosid) uronate (Me-GlcA-pNP) but no catalytic activity to benzyl-D-glucuronate (BnzGlcA), indicating the difference in substrate specificity from previously studied fungal GEs. A substantial increase in the release of monomeric sugars and glucuronic acid from autohydrolysis of corn bran was observed by the supplementing TtGEs into commercial xylanase; the results clearly demonstrated that the TtGEs played a significant role in this degradation process. This research on TtGEs enriches our knowledge of this novel class of fungal GEs. These newly characterized TtGEs could be used as promising accessory enzymes to improve the hydrolysis efficiency of commercial enzymes in saccharification of lignocellulosic materials due to their thermophilic characteristics.
Title: beta-Glucuronidase-coupled assays of glucuronoyl esterases Franova L, Puchart V, Biely P Ref: Analytical Biochemistry, 510:114, 2016 : PubMed
Glucuronoyl esterases (GEs) are microbial enzymes with potential to cleave the ester bonds between lignin alcohols and xylan-bound 4-O-methyl-d-glucuronic acid in plant cell walls. This activity renders GEs attractive research targets for biotechnological applications. One of the factors impeding the progress in GE research is the lack of suitable substrates. In this work, we report a facile preparation of methyl esters of chromogenic 4-nitrophenyl and 5-bromo-4-chloro-3-indolyl beta-D-glucuronides for qualitative and quantitative GE assay coupled with beta-glucuronidase as the auxiliary enzyme. The indolyl derivative affording a blue indigo-type product is suitable for rapid and sensitive assay of GE in commercial preparations as well as for high throughput screening of microorganisms and genomic and metagenomic libraries.
Title: Glucuronoyl esterase--novel carbohydrate esterase produced by Schizophyllum commune Spanikova S, Biely P Ref: FEBS Letters, 580:4597, 2006 : PubMed
The cellulolytic system of the wood-rotting fungus Schizophyllum commune contains an esterase that hydrolyzes methyl ester of 4-O-methyl-d-glucuronic acid. The enzyme, called glucuronoyl esterase, was purified to electrophoretic homogeneity from a cellulose-spent culture fluid. Its substrate specificity was examined on a number of substrates of other carbohydrate esterases such as acetylxylan esterase, feruloyl esterase and pectin methylesterase. The glucuronoyl esterase attacks exclusively the esters of MeGlcA. The methyl ester of free or glycosidically linked MeGlcA was not hydrolysed by other carbohydrate esterases. The results suggest that we have discovered a new type of carbohydrate esterase that might be involved in disruption of ester linkages connecting hemicellulose and lignin in plant cell walls.
