Irreversible Inhibitors Lab Report
irreversible enzyme Inhibitors
Irreversible enzymes are described as enzymes that require chemical activation. After chemical activation, the chemical reaction occurs between the target enzyme and the inhibitor. The chemical reaction results in the irreversible inhibition of the enzyme. In short, the enzyme catalyzes its own inactivation(Rando, 1974a). The purpose of irreversible inhibitors is to modifying key amino acid residues required for enzymatic activity. There are two types of irreversible inhibitors, which are the kcat and the Ks inhibitor. Although both are regarded as irreversible inhibitor, the method in which the enzyme is made irreversible varies. The kcat inhibitors occur when an enzyme converts a substrate which is chemically unreactive into a highly reactive product. The product …show more content…
then reacts with an active-site residue which then results in the irreversible inactivation of the enzyme (Rando, 1975). However, with the second type, the product from the enzymatic reaction is tightly bind to the enzyme that the enzyme seems irreversibly inactivated(Rando, 1975). ks Inhibitor
To describe the Ks inhibitor, lers consider the following enzymatic equation adapted from (Rando, 1975)
S+E ←/Ks ES →/kcat E+P
Where
S is the substrate
E is the enzyme
Ks is the dissociation constant to the enzyme kcat is a catalytic constant
The Ks inhibitors are constructed by attaching reactive function groups to a moiety that resembles an substrate (Rando, 1974a).
The selectivity of these inhibitors is governed by the magnitude of Ks, but usually the value of Ks cannot be measured(Rando, 1974b). Consequently, these means the inhibitors may bind to other biomolecules before binding to the selected enzyme.
Kcat Inhibitors
These inhibitors are of far better use than the Km inhibitors as the mechanism for these inhibitors is known. The kcat inhibitors consist of reactive groupings that can be activated by the target enzymes at their activation site(Rando, 1974a). Once the product is generated, a chemical reaction occurs between the product and enzyme leading to the irreversible inhibition of the enzyme. Unlike the Km inhibitor, which could react with other biomolecules before reacting with the targeted enzyme, these kcat enzymes have to be activated by the target enzyme. Examples of these inhibitors are, Δ(3.4) –decynoyl-NAC, pargyline, chlorogyline etc (Rando,
1974a).
Irreversible enzymes are described as enzymes that require chemical activation. After chemical activation, the chemical reaction occurs between the target enzyme and the inhibitor. The chemical reaction results in the irreversible inhibition of the enzyme. In short, the enzyme catalyzes its own inactivation(Rando, 1974a). The purpose of irreversible inhibitors is to modifying key amino acid residues required for enzymatic activity. There are two types of irreversible inhibitors, which are the kcat and the Ks inhibitor. Although both are regarded as irreversible inhibitor, the method in which the enzyme is made irreversible varies. The kcat inhibitors occur when an enzyme converts a substrate which is chemically unreactive into a highly reactive product. The product …show more content…
then reacts with an active-site residue which then results in the irreversible inactivation of the enzyme (Rando, 1975). However, with the second type, the product from the enzymatic reaction is tightly bind to the enzyme that the enzyme seems irreversibly inactivated(Rando, 1975). ks Inhibitor
To describe the Ks inhibitor, lers consider the following enzymatic equation adapted from (Rando, 1975)
S+E ←/Ks ES →/kcat E+P
Where
S is the substrate
E is the enzyme
Ks is the dissociation constant to the enzyme kcat is a catalytic constant
The Ks inhibitors are constructed by attaching reactive function groups to a moiety that resembles an substrate (Rando, 1974a).
The selectivity of these inhibitors is governed by the magnitude of Ks, but usually the value of Ks cannot be measured(Rando, 1974b). Consequently, these means the inhibitors may bind to other biomolecules before binding to the selected enzyme.
Kcat Inhibitors
These inhibitors are of far better use than the Km inhibitors as the mechanism for these inhibitors is known. The kcat inhibitors consist of reactive groupings that can be activated by the target enzymes at their activation site(Rando, 1974a). Once the product is generated, a chemical reaction occurs between the product and enzyme leading to the irreversible inhibition of the enzyme. Unlike the Km inhibitor, which could react with other biomolecules before reacting with the targeted enzyme, these kcat enzymes have to be activated by the target enzyme. Examples of these inhibitors are, Δ(3.4) –decynoyl-NAC, pargyline, chlorogyline etc (Rando,
1974a).