Search results
Results From The WOW.Com Content Network
Generally, the carbohydrate part(s) play an integral role in the function of a glycoconjugate; prominent examples of this are neural cell adhesion molecule (NCAM) and blood proteins where fine details in the carbohydrate structure determine cell binding (or not) or lifetime in circulation.
Carbohydrase is the name of a set of enzymes that catalyze five types of reactions, turning carbohydrates into simple sugars, from the large family of glycosidases. [ 1 ] Carbohydrases are produced in the pancreas , salivary glands and small intestine , breaking down polysaccharides .
Typical 1 H NMR chemical shifts of carbohydrate ring protons are 3–6 ppm (4.5–5.5 ppm for anomeric protons). Typical 13 C NMR chemical shifts of carbohydrate ring carbons are 60–110 ppm In the case of simple mono- and oligosaccharide molecules, all proton signals are typically separated from one another (usually at 500 MHz or better NMR ...
Carbohydrate chemistry is a field of study concerned with the synthesis, structure and function of carbohydrates. Due to the complexity of these structures, the chemical synthesis of carbohydrates has a variety of unique strategies and methods.
Unlike the biochemical processes, synthetic glycochemistry relies heavily on protecting groups [18] (e.g. the 4,6-O-benzylidene) in order to achieve desired regioselectivity. The other challenge of chemical glycosylation is the stereoselectivity that each glycosidic linkage has two stereo-outcomes, α/β or cis / trans .
The reverse anomeric effect, proposed in 1965 by R. U. Lemieux, is the tendency for electropositive groups at the anomeric position to be oriented equatorially. [1] Original publication reported this phenomenon with N-(2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl)-4-methylpyridinium bromide. However, further studies have shown the effect to be a ...
The carbohydrate may be in the form of a monosaccharide, disaccharide(s), oligosaccharide(s), polysaccharide(s), or their derivatives (e.g. sulfo- or phospho-substituted). One, a few, or many carbohydrate units may be present. Proteoglycans are a subclass of glycoproteins in which the carbohydrate units are polysaccharides that contain amino ...
Common O-GalNAc core structures; Core 1, Core 2 and poly-N-acetyllactosamine structures. Addition of N-acetylgalactosamine (GalNAc) to a serine or threonine occurs in the Golgi apparatus, after the protein has been folded. [1] [6] The process is performed by enzymes known as GalNAc transferases (GALNTs), of which there are 20 different types. [6]