Enzyme-carbohydrate interactions

Fluorinated carbohydrates have recently received much attention because of their importance in the study of the enzyme-carbohydrate interactions and their interesting biological activity [56], Hara et al. [57] achieved the deoxyfluorination of primary and anomeric hydroxyl groups of a series of protected carbohydrates, for example 65 into 66 (70%) (Scheme 12.31, a representative example) and 67 into 68 (90%) (Scheme 12.32, a representative example), with good yields, by use of N,N-diethyl-a,a-difluoro-(m.-methylbenzyl)amme (DFMBA), which has previously proved to be a selective reagent for the synthesis of fluorinated alcohols and carboxylic acids [58], Chemoselective deoxyfluorination at the anomeric position... 

Effect of Carbohydrate on Enzyme-Substrate Interaction. Since many of the enzymes we have conjugated with dextran have macromolecules as their natural substrates, we recognized that the conjugation process might result in unfavorable steric interactions that would impair the ability of the enzymes to interact with such substrates, in the same way that attached carbohydrate affects the susceptibility of the conjugated enzymes to proteolytic attack. We have therefore investigated the effect of carbohydrate on the interaction of conjugated enzymes with substrate. 

In conjunction with our overview of glycomimetics that block protein-carbohydrate interactions, we also discuss strategies to develop inhibitors of carbohydrate-processing enzymes this section focuses on the enzymes involved in bacterial cell wall biosynthesis because it is an area in which many new advances have been made. Enzymes that utilize sugars and synthesize glycoconjugates unique to pathogens have been identified, and cell-permeable inhibitors can be used to explore their biological roles or validate a potential... 

The best characterized protein-carbohydrate interactions occur in plant lectins. Other carbohydrate-binding proteins include immunoglobulins and enzymes. 

Protein-ligand interactions are important phenomena that touch upon every facet of biological functions. These include such examples as enzyme-substrate interactions in biochemical transformations, transducer-membrane interactions in signal transduction, protein-nucleic acid interactions in genetic transmission, protein-carbohydrate interactions in cell adhesion as well as protein-protein interactions in biochemical regulations and defense (immune response). Databases of interacting proteins are available respectively at DIP (http //dip.doe-mbi.ucla.edu) and IntAct project of EBI (http //ebi.ac.uk/intact). 

Morales. J.C. Zurita. D. Penades. S. Carbohydrate-carbohydrate interactions in water with glycophanes as model systems. J. Org. Chern. 1998. 63. 9212-9222. Habicher. T. Diederich, F. Catalytic dendrophanes as enzyme mimics Synthesis, binding properties, micropolarity effect, and catalytic activity of dendritic thiazolio-cyclophanes. Helv. Chim. Acta 1999. 82, 1066-1094. Bartsch, R.A. Kus, P. Dailey, N.K. Kou. X. A novel cyclophane-anthracene complex. Tetrahedron Lett. 2002. 43. 5017-5019. 

---