Enzyme – Enzyme – Enzyme!!!! What is it ???? Lets see……
Inhibitors• Inhibitors are chemicals that reduce the rate of enzymic reactions• The are usually specific and they work at low concentrations• They block the enzyme but they do not usually destroy it• Many drugs and poisons are inhibitors of enzymes in the nervous system
Enzyme InhibitorsEnzyme inhibitors are molecules that reducethe catalytic activity of enzymes. Reducing ofeffective enzymatic activity or completeblocking of enzyme may cause eithercomplete death of cell either modifications inthe pathways.Appln: Drugs with cause complete inactivationof enzymes from essential pathways will causecell death and therefore such drugs can be usedas an antibiotics.
Classification:• Basis of Reversibility: – Reversible – Irreservisible• Basis of Competitiveness: – Competitive – Un Competitive – Mixed
Basis of Reversibility:• Reversible• Reversible inhibitors bind to enzyme with only non covalent interactions.• Reversible inhibitors do not perform any chemical changes in enzyme or themselves and they are in dynamic equilibrium with solution and can be removed from enzyme completely by reducing inhibitor concentration in solution.• Reversible inhibition is often used as a self-regulated process in living cells, when the substrate or product of some enzymes acts as inhibitors for other enzymes.
Basis of Reversibility:• Irreversible• Irreversible inhibitors binds to enzyme via covalent bonds and prevent enzyme from further performing of catalytic acts.• It is necessary to understand, that irreversible inhibitors act on some selected group of enzymes, with no effect on other enzymes and proteins.• According to this classification it is impossible to consider chemical or physical agents which inactivate all enzymes and protein as an inhibitors.
Comparison:Reversible IrreversibleBinds via non covalent Binds via covalentinteractions interactionsDo not perform any Inhibitor binds to thechemical changes substrate and prevent catalytic activity of enzymes.Can be reversed, as there Irreversibility due to strongis no bonding between the covalent bonding.inhibitor and substrate.
Basis of competitiveness:• Competitive Inhibition –As the name implies, compete with the substrate for active site of the enzyme. –Inhibitor is similar to natural substrates. –Most commonly occurred process.
Competitive – Uncompetitive!!! What is it ???? Lets see……