Carbohydrate-protein interaction hydrogen bonding

The precise chemical interactions between an adhesin and its receptor are also important. For example, direct- and water-mediated hydrogen bonds are the most important interactions within the carbohydrate-recognition domain in carbohydrate-binding adhesins on the host cell surface (Weis and Drickamer, 1996). Nonpolar van der Waals interactions and hydrophobic "stacking of the receptor oligosaccharide rings with aromatic amino acid side chains of the bacterial adhesin protein also contribute to oligosaccharide-protein interactions. X-ray structural... 

Nucleic acids, proteins, some carbohydrates, and hormones are informational molecules. They carry directions for the control of biological processes. With the exception of hormones, these are macromolecules. In all these interactions, secondary forces such as hydrogen bonding and van der Waals forces, ionic bonds, and hydrophobic or hydrophilic characteristics play critical roles. Molecular recognition is the term used to describe the ability of molecules to recognize and interact bond—specifically with other molecules. This molecular recognition is based on a combination of the interactions just cited and on structure. 

The recognition is the binding of a carbohydrate by a specific receptor, which is usually part of a protein (enzyme, immunoglobuUn, lectin). The process is due to the sum of weak interactions (van der Waals-London, hydrogen bonds) that may results in high association constants. 

During the extraction process three types of interactions are usually disrupted, these are van der Waals forces in lipid-lipid, lipid-protein, and liquid-carbohydrate complexes electrostatic and hydrogen bonding interactions between lipids andproteins andcovalent bonding between lipids, carbohydrates, and proteins (Roby t and White, 1987). The solvent of choice depends on the type of lipid and the interactions to be disrupted. Thus, neutral lipids may be extracted with nonpolar solvents, while phospholipids and glycolipids are extracted with more polar solvent mixtures (Shahidi and Wanasundara, 1998). 

Other factors also affect protein stability and hyperstabihty (Vetriani et al, 1998 Jaenicke, 1996, 1998, 2000 Daniel and Danson, 2001). These include the formation of a network of surface ionic pairs, hydrogen bonding, local interactions, the stabilization of polypeptides helices (the packing and docking of domains, association of subunits, conjugation with prosthetic groups and carbohydrate moieties, etc). 

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