Bonds oside

The donor system varies according to the various types of hydrolases and the transferable group may be attached by a peptide bond, oside bond, ester bond, amine linkage, amide bond or an amidine linkage. 

P212121 Z = 4 D, = 1.413 R = 0.041 for 3,165 intensities. Thepyran-oside conformation is 4C1, with Q = 58 pm, 6 = 5°. The primary alcohol group is gauche-trans. The linkage-bond torsion-angles are O-5-C-l-0-1 -C-7 = — 87°, C-1-0-1-C-7-0-7 = — 67°. The two rings of the monoterpene moiety are inclined to each other, with C-C-C-C torsion-angles, about the common bond, of 149 and —97°. 

M. Quirasco, A. Lopez-Munguia, V. Pelenc, M. Remaud, F. Paul, and P. Monsan, Enzymatic production of glucooligosaccharides containing a-(1 —> 2) osidic bonds. Potential application in nutrition, Ann. NY Acad. Sci., 750 (1995) 317-320. 

Furthermore, it has been demonstrated that these mannoproteins share covalent bonds with glucane (Moine-Ledoux and Dubourdieu, 1999). They remain in the cell walls treated simultaneously with sodium dodecyl sulfate (SDS) (which cuts the hydrogen bonds) and /i-mercaptoethanol (Figure 1.21), which do not affect osidic bonds. 

Fig. 3.16. Basic structure of a-homogalacturane. Chain of partially methylated galacturonic acid units, linked by a-(l,4)-type oside bonds...

The a-(l,4)-type oside bonds in the homogalac-turonan chain form a secondary open-helix structure, where each coil consists of three galacturonic acid units. When the G -GalA-(l,2)-Q -Rha-(l,4)-Q -GalA sequence is inserted, the axis of the helix pivots through 90°, producing what is known as the pectic bend . 

Arabinogalactan II (AG-II) (Figure 3.19b) has a more complex structure. It has a main chain of galactose units linked by /S-(l,3) oside bonds, with short lateral chains of galactose, bonded on /S-(l,6). In C3, these are replaced by individual... 

This group of enzyme (EC 3.2.1-xx) catalyzes the hydrolysis of glycosidic bonds in carbohydrate-carbohydrate or carbohydrate-aglycone (noncarbohydrate moiety) entities. They can be classified in two distinctive groups as they are able to cleave internal or external osidic linkages (Fig. 4) ... 

These substances are the result of the combination of a base (most frequently a purine or pyrimidine base) with a sugar (o-ribose) or desoxy-sugar (desoxyribose) by means of an oside bond. Since many of these substances occur in nucleic adds, they are called nudeosides . 

The polysaccharide molecule is formed by the association, by means of oside bonds, of a large number ( ) of sugar molecules. The uronic acids are associated into polyuronides in the same way as the sugars form polysaccharides. 

OsiDE OR Peptide Bonds (a) Biosynthesis of Complex Lipids... 

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