Role in physiological processes

Jackson, R.L., Busch, S.J., Cardin, A.D. (1991) Glycosaminoglycans molecular properties, protein interactions, and role in physiological processes. Physiol. Rev. 71, 481-539. 

As indicated above, C, H, O and other elements (such as N or P) can bind in a range of combinations to make simple compounds such as those given in Table 1.1. However, the same elements can also bind together to form much more complex structural and functional compounds (or biomolecules) which play vital roles in physiological processes. Major classes of these complex biomolecules are outlined in the boxes below. 

Cathepsins comprise a family of enzymes within the papain superfamily of cysteine proteases that play important roles in physiological processes such as bone resorption, tumor metathesis, and rheumatoid arthritis. Recently we reported a series of novel compounds which exhibit potent inhibitory activity against cathepsin L. To explore further this novel class, we have constructed a library of thiocarbazates and tested them against a panel of serine and cysteine proteases. Preliminary studies reveal that some of these compounds are highly selective for cathepsin S over B and L, with nanomolar IC50 values. The results of these studies will be described. 

Interaction of proteins with water, drugs, and other biological macromolecules plays an essential role in physiological processes. Owing to the very high number of atoms in a protein, in general, such interactions cannot be handled at the atomic level explicitly simplified, stUl reliable models are needed. 

Sections I-V of this chapter deal with the syntheses of unsaturated organic compounds playing an essential role in biochemical processes of life. Numerous polyunsaturated compounds have been synthesized in order to elucidate their physiological role, for instance in brain. However, the main impact on permanent searches for new improved methods of synthesis of isotopically labelled dienes and polyenes comes from nuclear medicine and nuclear pharmacy. The deuterium and carbon-13 labelled polyunsaturated compounds are needed as internal standards in mass spectral determinations of very low concentrations of biologically active substances in biological fluids. 

The molecular details of the physiologically critical step of iron release from serum transferrin are unclear. The anion may play an important role in this process by providing a handle for modulating the affinity of transferrin for iron. If the anion were to be removed (perhaps by protonation followed by dissociation), then the binding of iron to transferrin would be greatly weakened, facilitating dissociation of the metal. It seems... 

Muscarinic agonists such as muscarine and pilocarpine and antagonists such as atropine, the racemic form of natural hyoscyamine, have been known for more than a century. Only recently more selective ligands have been found that will hopefully generate a better understanding of the role mAChR subtypes in physiological processes and especially brain function. 

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