,Introduction
• Enzyme inhibitors are the substance which when binds to the enzyme reversibly or
irreversibly, decreases the activity of enzyme and the process is known as enzyme
inhibition.
• By binding to active sites inhibitors reduce the compatibility of substrates and
substrates and enzyme and this lead to the inhibition of enzyme – substrates
complexes formation ,preventing the catalysis of reactions and decreasing the
amount of product produced by a reaction.
• Enzyme inhibitors are used to gain information about the shape of active site of
enzyme and amino acids residues in active site.
• They are used to gain information about regulation or control of metabolic pathway.
• They can be used for drug designing.
• They are important for correcting metabolic imbalance.
• They are used for designing herbicides, pesticides and for killing pathogen.
• Concentration of enzyme inhibitors increases, the rate of enzyme activity decrease .
• The amount of product produced is inversely proportional to concentration of
inhibitors molecules.
, Enzyme inhibition types:
Enzyme inhibition type can be classified into different type based on
following parameter
1. On the basis of specificity:
• Co-enzyme inhibitor: Inhibits co-enzymes only. E.g. cyanide hydrazine, hydroxyl amine
inhibits co-enzyme pyridoxal phosphate.
• Ion-cofactor inhibitor: E.g. fluoride chelate Mg2+ ion of enolase enzyme.
• Prosthetic group inhibitor: E.g. cyanide inhibit Heme of cytochrome oxidase.
• Apoenzyme inhibitor:E.g. antibiotics
• Physiological modulator:
2. On the basis of origin:
• Natural enzyme inhibitor: E.g. Alfatoxin, – amanitin
• Artificial enzyme inhibitor (synthetic): E.g. drugs
3. On the basis of whether the inhibition is reversible or irreversible
1. Irreversible Inhibition
2. Reversible inhibition
• Competitive inhibition
• Non-competitive inhibition
• Uncompetitive inhibitor
• Mixed inhibition
• Enzyme inhibitors are the substance which when binds to the enzyme reversibly or
irreversibly, decreases the activity of enzyme and the process is known as enzyme
inhibition.
• By binding to active sites inhibitors reduce the compatibility of substrates and
substrates and enzyme and this lead to the inhibition of enzyme – substrates
complexes formation ,preventing the catalysis of reactions and decreasing the
amount of product produced by a reaction.
• Enzyme inhibitors are used to gain information about the shape of active site of
enzyme and amino acids residues in active site.
• They are used to gain information about regulation or control of metabolic pathway.
• They can be used for drug designing.
• They are important for correcting metabolic imbalance.
• They are used for designing herbicides, pesticides and for killing pathogen.
• Concentration of enzyme inhibitors increases, the rate of enzyme activity decrease .
• The amount of product produced is inversely proportional to concentration of
inhibitors molecules.
, Enzyme inhibition types:
Enzyme inhibition type can be classified into different type based on
following parameter
1. On the basis of specificity:
• Co-enzyme inhibitor: Inhibits co-enzymes only. E.g. cyanide hydrazine, hydroxyl amine
inhibits co-enzyme pyridoxal phosphate.
• Ion-cofactor inhibitor: E.g. fluoride chelate Mg2+ ion of enolase enzyme.
• Prosthetic group inhibitor: E.g. cyanide inhibit Heme of cytochrome oxidase.
• Apoenzyme inhibitor:E.g. antibiotics
• Physiological modulator:
2. On the basis of origin:
• Natural enzyme inhibitor: E.g. Alfatoxin, – amanitin
• Artificial enzyme inhibitor (synthetic): E.g. drugs
3. On the basis of whether the inhibition is reversible or irreversible
1. Irreversible Inhibition
2. Reversible inhibition
• Competitive inhibition
• Non-competitive inhibition
• Uncompetitive inhibitor
• Mixed inhibition
