scholarly journals cDNA Isolation and Functional Characterization of UDP-d-glucuronic Acid 4-Epimerase Family from Ornithogalum caudatum

Molecules ◽  
2016 ◽  
Vol 21 (11) ◽  
pp. 1505 ◽  
Author(s):  
Sen Yin ◽  
Yu-Jia Sun ◽  
Ming Liu ◽  
Li-Na Li ◽  
Jian-Qiang Kong
RSC Advances ◽  
2016 ◽  
Vol 6 (44) ◽  
pp. 37370-37384 ◽  
Author(s):  
Sen Yin ◽  
Jian-Qiang Kong

A transcriptome-guided discovery and functional identification of UGE and UXE families were presented. Importantly, OcUGE1/2 and OcUXE1 were preliminarily revealed to be responsible for the biosynthesis of anticancer polysaccharides inO. caudatum.


2001 ◽  
Vol 183 (6) ◽  
pp. 2093-2100 ◽  
Author(s):  
Jason C. Hurlbert ◽  
James F. Preston

ABSTRACT A β-1,4-xylan hydrolase (xylanase A) produced by Erwinia chrysanthemi D1 isolated from corn was analyzed with respect to its secondary structure and enzymatic function. The pH and temperature optima for the enzyme were found to be pH 6.0 and 35°C, with a secondary structure under those conditions that consists of approximately 10 to 15% α-helices. The enzyme was still active at temperatures higher than 40°C and at pHs of up to 9.0. The loss of enzymatic activity at temperatures above 45°C was accompanied by significant loss of secondary structure. The enzyme was most active on xylan substrates with low ratios of xylose to 4-O-methyl-d-glucuronic acid and appears to require two 4-O-methyl-d-glucuronic acid residues for substrate recognition and/or cleavage of a β-1,4-xylosidic bond. The enzyme hydrolyzed sweetgum xylan, generating products with a 4-O-methyl-glucuronic acid-substituted xylose residue one position from the nonreducing terminus of the oligoxyloside product. No internal cleavages of the xylan backbone between substituted xylose residues were observed, giving the enzyme a unique mode of action in the hydrolysis compared to all other xylanases that have been described. Given the size of the oligoxyloside products generated by the enzyme during depolymerization of xylan substrates, the function of the enzyme may be to render substrate available for other depolymerizing enzymes instead of producing oligoxylosides for cellular metabolism and may serve to produce elicitors during the initiation of the infectious process.


2019 ◽  
Vol 22 (3) ◽  
pp. 271-278
Author(s):  
Yan Yang ◽  
Ying-Ying Wang ◽  
Min-Zhi Liu ◽  
Zhi-Ying Sun ◽  
Wei Wang

2020 ◽  
Vol 477 (7) ◽  
pp. 1261-1286 ◽  
Author(s):  
Marie Anne Richard ◽  
Hannah Pallubinsky ◽  
Denis P. Blondin

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.


Sign in / Sign up

Export Citation Format

Share Document