Rational Design Of Compounds Research Articles

Identification of CFTR activators and inhibitors: chance or design?

The cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP-activated Cl(-) channel expressed in various epithelial cells, and is a pharmacological target for activators and inhibitors. Activators are useful for the pharmacotherapy of cystic fibrosis, specifically for those mutations that affect CFTR protein by reducing its ability to stay in the open state. Conversely, inhibitors are potentially useful to treat secretory diarrhoea caused by enterotoxins, as the CFTR is the main route for Cl(-) flux in the intestine. Recently, a variety of potent modulators of the CFTR Cl(-) channel activity have been identified by high-throughput screening of a large collections of small molecules. The identification of CFTR activators and inhibitors with novel chemical scaffolds might help with the rational design of compounds with improved pharmacological properties.

Tachykinins and tachykinin receptors: structure and activity relationships.

In addition to the classical neurotransmitters, acetylcholine and noradrenaline, a wide number of peptides with neurotransmitter activity have been identified in the past few years. Among them, the tachykinins substance P (SP), neurokinin A (NKA) and neurokinin B (NKB) appear to act as mediators of nonadrenergic, noncholinergic (NANC) excitatory neurotransmission. Tachykinins interact with specific membrane proteins, belonging to the family of G protein-coupling cell membrane receptors. Until now, three tachykinin receptors termed NK1 (NK1R), NK2 (NK2R) and NK3 (NK3R) have been cloned in different species. A large amount of reports suggests that these peptides are involved in nociception and neuroimmunomodulation, and in the development of different diseases such as bronchial asthma, inflammatory bowel syndrome and psychiatric disorders. Tachykinin receptor antagonists are therefore promising, therapeutically relevant agents. However, and in spite of extensive research, the obtention of selective antagonists of tachykinin receptors have revealed very difficult. An understanding of how ligands interact with their receptors is essential to permit a rational design of compounds acting selectively at the tachykinin receptor level. The major aim of the present article is to review the structure-activity data that exist for tachykinins and their receptors, with the purpose of getting insight into basic structural requirements that determine ligand/receptor interaction.

Structural diversity of heparan sulfate binding domains in chemokines.

Heparan sulfate (HS) molecules are ubiquitous in animal tissues where they function as ligands that are dramatically involved in the regulation of the proteins they bind. Of these, chemokines are a family of small proteins with many biological functions. Their well-conserved monomeric structure can associate in various oligomeric forms especially in the presence of HS. Application of protein surface analysis and energy calculations to all known chemokine structures leads to the proposal that four different binding modes are created by the folding and oligomerization of these proteins. So, based on the present state of our knowledge, four different clusters of amino acids should be involved in the recognition process. Our results help to rationalize how unique sequences of HS specifically bind any given chemokine. The conclusions open the route for a rational design of compounds of therapeutical interest that could influence chemokine activity.

Antibody geometry and form: three-dimensional relationships between anti-idiotypic antibodies and external antigens

Anti-idiotypes have been developed to mimic a wide variety of antigens in studies of antibody-antigen interactions. Molecular, biochemical and structural analysis of antibody-anti-idiotype pairs presents an excellent model for study of complex protein-protein interactions. An understanding of the ways in which anti-idiotypes mimic antigens and the features determining binding characteristics will facilitate rational design of compounds with biological, enzymatic, pharmaceutical and chemical applications.