Beta linkages

The main raw material required for the production of viscose is ceUulose (qv), a natural polymer of D-glucose (Fig. 1). The repeating monomer unit is a pair of anhydroglucose units (AGU). CeUulose and starch (qv) are identical but for the way in which the ring oxygen atoms alternate from side to side of the polymer chain (beta linkages) in ceUulose, but remain on the same side (alpha linkages) in starch. 

Fig. 1. Anhydro-glucose units with 1—4 beta linkages as in ceUulose.

Hakomori methylation analysis, and preparation and GLC gf the PAAN derivatives (4), were used to determine the linkages. C NMR of partially hydrolysed samples confirmed the octasaccharide repeat unit, the beta linkages and the presence of the carboxylic acids. 

The first group is comprised that of compounds which potentially could be degraded to form G-l-P by phosphorolysis by beta-linkage specific enzymes. They include IPTGlu, cellobiose, sophorose, salicin, and sucrose. Addition of these compounds, or exogenous G-l-P, to Solka Floe fermentations improved maximum cellulase yields from 171 to 309%, and the time period for enzyme synthesis was reduced from 95 to 59% compared with using Solka Floe only. 

Spiro, R.G., Yasumoto, Y., and Bhoyroo, V., 1996, Characterization of a rat liver Golgi sulphotransferase responsible for the 6-O-sulphation of N-acetylglucosamine residues in beta-linkage to mannose role in assembly of sialyl-galactosyl-N-acetylglucosamine 6-sulphate sequence of N-linked oligosaccharides. Biochem. J. 319, 209-216... 

Cellulose is the most abundant polysaccharide. It is the fibrous component of a plant cell wall (e.g., cotton). Cellulose molecules are chains of molecules of up to 14,000 units of D-glucose linked together by beta linkages ... 

In polyuronides the glycosidic bond may be attached to any of the carbons 2 to 6. The ease of hydrolysis of these compounds may be influenced by variation in the point of attachment. Alpha glycosidic linkages seem to be more easily ruptured than beta linkages. 

The synthesis of AG or LAM arabinan is complicated by the presence of -linked arabinofu-ranosyl moieties. The beta-linkage is difficult to construct because the substituents at Cl and C2 are cis. Sterics favor formation of the frawi -glycoside, and neighboring group participa-... 

Hydrolysis of the l, 4-beta-linkages between N-acetyl-D-glucosamine and N-acetylmuramic acid in peptidoglycan heteropolymers of the prokaryotes cell walls. 

Human lysozyme (hLZ) hydrolyzes 1,4-beta-linkage between N-acetyhnuramic acid and N-acetyl-D-glucosamine residue in peptidoglycan. Human LZ exhibits antibacterial, antiviral, antifungal and antiparasitic... 

Different from trigger proteins, parvalbumin and calbindinD9k function as calcium-buffer proteins. Calcium binding to both proteins does not lead to conformational change with an exposed hydrophobic surface. The structure of a carp parvalbumin was the first structure in the EF-hand protein family. It has two isoforms a and 0) with very similar structures. Oncomodulin is the mammalian beta linkage parvalbumin. The structure of parvalbumin comprises three helix-loop-helix motifs, called AB, CD, and EF initially (Figure 11). The calcium-binding loop in the first... 

On the other hand, if the thousands of glucose units are linked by beta 1-4 bonds, that molecule is called cellulose. Plants use this polymer as part of their structural material for building stems and leaves. The geometry of these beta linkages allows the long cellulose chains to align themselves side-by-side and thus create strong fibrous strands. 

Rudenko, A.E., Latif, A.A., Thompson, B.C., 2014. Influence of beta-linkages on the morphology and performance of DArP P3HT-PC61BM solar cells. Nanotechnology 25,014005. 

M. G. Cross, D. Walton, N. J. Morse, R. J. Mortimer, D. R. Rosseinsky, D. J. Simmonds, A voltammetric survey of steric and beta-linkage effects in the electropolymerization of some substituted pyrroles, Journal of Electroanalytical Chemistry 1985, 189, 389. 

Fig. 1. Anhydroglucose units with 1-4 beta linkages as in cellulose.

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