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|Storage Temperature:||Below -10oC|
|Stability:||> 10 years under recommended storage conditions|
|Substrate For (Enzyme):||endo-1,4-β-Xylanase, α-Glucuronidase|
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High purity 23-(4-O-Methyl-α-D-Glucuronyl)-xylotriose for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
Unique features of the bifunctional GH30 from Thermothelomyces thermophila revealed by structural and mutational studies.
Nikolaivits, E., Pentari, C., Kosinas, C., Feiler, C. G., Spiliopoulou, M., Weiss, M. S., Dimarogona, M. & Topakas, E. (2021). Carbohydrate Polymers, 273, 118553.
Fungal xylanases belonging to family GH30_7, initially categorized as endo-glucuronoxylanases, are now known to differ both in terms of substrate specificity, as well as mode of action. Recently, TtXyn30A, a GH30_7 xylanase from Thermothelomyces thermophila, was shown to possess dual activity, acting on the xylan backbone in both an endo- and an exo- manner. Here, in an effort to identify the structural characteristics that append these functional properties to the enzyme, we present the biochemical characterization of various TtXyn30A mutants as well as its crystal structure, alone, and in complex with the reaction product. An auxiliary catalytic amino acid has been identified, while it is also shown that glucuronic acid recognition is not mediated by a conserved arginine residue, as shown by previously determined GH30 structures.Hide Abstract
Rapid profiling strategy for oligosaccharides and polysaccharides by MALDI TOF mass spectrometry.
Wang, J., Zhao, J., Nie, S., Xie, M. & Li, S. (2021). Food Hydrocolloids, 124, 107237.
The application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) in glycan was limited due to their poor ionization efficiency, compared with biomolecules such as proteins and peptides. Aiming to improve the ionization efficiency and simplify preparation procedure simultaneously during MALDI MS analysis, an on-target derivatization method using 3-aminoquinoline (3-AQ)/α-cyano-4-hydroxycinnamic acid (CHCA) as matrix was employed and it was conducted both in the positive and negative ion MALDI TOF MS. Results indicated that after on-target derivatization, the ions generated had substantially improved S/N ratios and sensitivity in the tandem mass spectra. The B/Y- type ions of 3-AQ-labeled glycans could be easily recognized, and cross-ring A- type ions provided additional information to reveal the linkage patterns. Specifically, positive ion mass spectra with protonated adduct as precursor ion produced a simple fragmentation pattern benefited for sequencing and observation of branches. Furthermore, this method was successfully applied in polysaccharides analysis, including arabinoxylan, xylan, arabinogalactan and dextran after enzymatic or acid degradation. This study demonstrated that it was feasible to analyze higher molecular weight polysaccharides by MALDI TOF MS using 3-AQ/CHCA matrix through appropriate hydrolysis, and it allowed much efficient structural interpretation with increased sensitivity and characteristic fragment ions.Hide Abstract
Xylanase from marine filamentous fungus Pestalotiopsis sp. AN-7 was activated with diluted salt solution like brackish water.
Koh, S., Mizuno, M., Izuoka, Y., Fujino, N., Hamada-Sato, N. & Amano, Y. (2021). Journal of Applied Glycoscience, 68(1), 11-18.
The genus Pestalotiopsis are endophytic fungi that have recently been identified as cellulolytic system producers. We herein cloned a gene coding for a xylanase belonging to glycoside hydrolase (GH) family 10 (PesXyn10A) from Pestalotiopsis sp. AN-7, which was isolated from the soil of a mangrove forest. This protein was heterologously expressed by Pichia pastoris as a host, and its enzymatic properties were characterized. PesXyn10A was produced as a glycosylated protein and coincident to theoretical molecular mass (35.3 kDa) after deglycosylation by peptide-N-glycosidase F. Purified recombinant PesXyn10A exhibited maximal activity at pH 6.0 and 50°C, and activity was maintained at 90 % at pH 5.0 and temperatures lower than 30°C for 24 h. The substrate specificity of PesXyn10A was limited and it hydrolyzed glucuronoxylan and arabinoxylan, but not β-glucan. The final hydrolysis products from birchwood xylan were xylose, xylobiose, and 1,23-α-D-(4-O-methyl-glucuronyl)-1,4-β-D-xylotriose. The addition of metallic salts (NaCl, KCl, MgCl2, and CaCl2) activated PesXyn10A for xylan degradation, and maximal activation by these divalent cations was approximately 160% at a concentration of 5 mM. The thermostability of PesXyn10A significantly increased in the presence of 50 mM NaCl or 5 mM MgCl2. The present results suggest that the presence of metallic salts at a low concentration, similar to brackish water, exerts positive effects on the enzyme activity and thermal stability of PesXyn10A.Hide Abstract