Question

Phenyl-methane-sulfonyl-fluoride (PMSF) inactivates serine proteases by binding covalently to the catalytic serine residue at the active site; this enzyme-inhibitor bond is not cleaved by the enzyme. This is an example of what kind of inhibition? A) Irreversible B) Competitive C) Non-competitive D) Mixed E) pH inhibition

Answer 1

The phenomenon described in the question is an example of irreversible inhibition, where an inhibitor binds covalently to the active site of an enzyme.

Step-by-step explanation:

The phenomenon described in the question is an example of irreversible inhibition.

Irreversible inhibition occurs when an inhibitor binds covalently to the active site of an enzyme, rendering the enzyme permanently inactive. In the case of Phenyl-methane-sulfonyl-fluoride (PMSF), it inactivates serine proteases by covalently bonding to the catalytic serine residue at the active site, and this bond is not cleaved by the enzyme.

Examples of irreversible inhibitors include iodoacetate, which permanently inhibits aldolase, and di-isopropylflurophosphate (DFP), a component of nerve gas that permanently inhibits most digestive enzymes in humans.

Answer 2

Phenyl-methane-sulfonyl-fluoride (PMSF) inactivates serine proteases by binding covalently to the catalytic serine residue at the active site, this enzyme-inhibitor bond is not cleaved by the enzyme. This is an example of an Irreversible kind of inhibition.

Step-by-step explanation:

• Cell Lysates are prepared by using Phenyl-methane-sulfonyl-fluoride (PMSF). This PMSF is an enzyme inhibitor that inactivates serine proteases.
• It inactivate the serine proteases by attaching with the catalytic serine, Which was in an active state.
• The PMSF bond was not separated by the enzyme. So this action cannot be repeated. Hence it is an irreversible kind of inhibition.
• Handling of PMSF should be done in a fume hood and while handling it we should wear gloves.