Protein competitive

Multiple drug interactions can occur with the TCA drugs. Because of their high degree of binding to plasma proteins, competition for binding sites can exist between TCAs and phenytoin, aspirin, phenothiazines. 

All the HIV protease inhibitors have in common a specific effect against the aspartic HIV protease that cleaves viral proteins to yield structural proteins. Competitive inhibition of this process by the protease inhibitors results in the production of immature, non-infections virus particles. These drugs are also characterized by their high specificity, being more than a thousand-fold more active against viral than human aspartic proteases. 

As for reduction processes, C02 free radicals were shown to react specifically with disulfide bonds (122). They were extensively used to study the redox properties of disulfide bonds, thiyl and disulfide free radicals in proteins. This is discussed in paragraph 5. However, they do react with thiol functions also (37). For proteins containing a prosthetic group, the reduction concerns also oxidized valencies of metals and flavins. Flavin adenine dinucleotide (FAD) or Flavin Mononucleotide (FMN). The proportion of reduced disulfide/reduced prosthetic group varies considerably with the protein. For instance, lipoamide dehydrogenase contains one disulfide bond close to a flavin (FAD). Free radicals can reduce only the flavin, although both are in the active site (123). In chicken egg white riboflavin binding protein, competitive formation of both disulfide and semireduced flavin is observed (124). 

Plasma protein competition (Fig. 1.1) Drugs that bind to plasma proteins may compete with other drugs for the protein binding sites. Displacement of a Drug A from plasma proteins by Drug B may increase the concentration of unbound Drug A to toxic levels. 

The organization of the adsorbed protein layer is influenced by differences in the surface activity of proteins, competition in mixtures, and complex displacement kinetics. 

Ligand L and inhibitor i bind to the same binding sites (1) on the binding protein (competitive inhibition) ... 

Several models for mode of antifungal action of thiosulfinates were suggested by various researchers. Yamada and Azuma (1977) reported that allicin in the concentration of 3.13 pg/mL inhibited swelling and germination of fungi spores in nutritious media. Barone and Tansey (1977) showed that garlic and allicin suppressed C. albicans cell metabolism by the inactivalion of proteins, competitive inhibition of sulfhydryl compounds, or by the noncompetitive inhibition of enzyme function by oxidation. In another study, the deformation and distortion of yeast cells, cell... 

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