Carbohydrate residues flexibility

In conclusion, these results show that (1) dynamics of LCA are increased as the result of the carbohydrate residues flexibility. (2) presence of a, 1,6 fucose inhibits the effect of the other carbohydrate residues as the result of the tight bond between the sugar and the lectin. 

Figure 15.17 The three-dimensional structure of an intact IgG. Hinge regions connecting the Fab arms with the Fc stem are relatively flexible, despite the presence of disulfide bonds in this region linking the heavy and light chains. Carbohydrate residues that bridge the two Ch2 domains are not shown. (Courtesy of A. McPherson and L. Harris, Nature 360 369-372, 1992, by copyright permission of Macmillan Magazines Limited.)...

While pioneering work with flexible carbohydrate residues was done a decade ago (5), CA with flexible residues over all of space is a recent development (6-9). 

Since calcofluor binds to the pocket of a i-acid glycoprotein, the observed thermal quenching could also be the result of a local flexibility that originates from both the carbohydrate residues surrounding the fluorophore and the amino acids of the glycosylation site within the pocket. In fact, flexibility and local motions were observed for Trp residues in both sialylated and asialylated a i-acid glycoprotein. 

Alternative strategies utilizing the initial introduction of suitable chemical functionality onto the fullerene have been adopted by several research groups, allowing conjugation of the saccharides with complementary functions in the final synthetic steps. This approach has led to improved flexibility with the chemical functions on the carbohydrate moieties, especially the anchoring ones, and a better control on the number of attached saccharide residues. 

In the PPA-a-AI 1 complex, a flexible loop of the enzyme, which would normally contact the substrate, is pushed outward to allow entry of the inhibitor, and one of the key aspartate residues is held in a conformation similar to that observed in the free enzyme. Therefore, some changes relative to the carbohydrate complex are required in order to accommodate the inhibitor. The structurally mimetic interactions within the catalytic site are supplemented by other specific protein-protein interactions, with a substantial buried surface area at the interface, involving 50 residues of the enzyme [171]. 

The wood pyrolysis is attractive because forest and industrial wood residues can be readily converted into liqtrid products. These liqtrids, as erode bio-oil or slurry of charcoal of water or oil, have advantages in transport, storage, combustion, retrofitting and flexibility in production and marketing (Demirbas, 2007). In the first step of pyrolysis of carbohydrates dehydration occtrrs and at low temperatures dehydration predominates. Dehydration is also known as a char-forming reaction. Between 550 and 675 K volatile products, tar, and char are formed. The volatile products are CO, CO, H O, acetals, furfural, aldehydes and ketones. Levoglucosan is the principle component in tar. 

The modeling of carbohydrates is undergoing rapid development. For example, the first comprehensive conformational mappings of disaccharides with flexible residues and the first molecular dynamics studies of carbohydrates have only recently been published. At the same time, interest in carbohydrates has been increasing dramatically, and there is a need for a publication that gently introduces the uninitiated and provides an overview of current research in the area. We feel that Computer Modeling ( Carbohydrate Molecules meets these needs. 

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