Binding and Linkage. Functional

Wyman, J. and Gill, S.J. (1990), Binding and Linkage. Functional Chemistry of Biological Macromolecules, University Science Books, Mill Valley, CA, USA. 

A directly proportional correlation has been reported [28] between 5-HT3 binding and inhibition of 5-HT-induced nerve depolarization with selected compounds BRL 43594, GR 65630, GR 38032F, quipazine, ICS 205-530, MDL 72222 and metoclopramide (listed in order of decreasing potency). Thus, a linkage between functional and receptor affinity has been established in vitro. 

The basic decarboxylation mechanism is analogous to mechanisms of other PLP-dependent processes (Scheme VIII) 101-104). PLP is initially bound covalently to the enzyme via a Schiff base linkage to a lysine amino group. Other functional groups of PLP, particularly the phosphate, form strong noncovalent interactions with the enzyme. The substrate binds and reacts to form a bound PLP-substrate Schiff base. 

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... 

In one sense, this has been the approach in any broad, synthetic approach where a systematic replacement of substituents is done on a reference molecule. Assumptions are made that aliphatic moieties fit into hydrophobic pockets, anionic residues bind by an ionic bond to a positive charged group such as the c-amino of lysine, cationic residues bind by a salt linkage to the anionic residues of aspartic or glutamic acids, alcohols and amides hydrogen bond to electron rich moieties such as oxygen, nitrogen and sulfur functions. 

In the specific case of nanotubes, biofunetionalization for enhanced compatibility has been an area of rapid growth during recent years (154). Several studies have focused on the binding of proteins to SWNT via noncovalent and covalent functionalization schemes. For example, Dai et al. (155) have adsorbed pyrene onto the side-walls of SWNT and then have made the succinimidyl ester group react with the amine groups in the lysine residues of the proteins to form covalent amide linkages. Similarly, MWNT have been functionalized with 4-hydroxynonenal to induce adsorption of the 4-hydroxynonenal antibody (156). 

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