Question

Which of the following conjugation reactions DOES NOT REQUIRE reaction with an activated conjugating agent?

• A. Glucouronidation
• B. Sulfation
• C. Methylation
• D. Glutathione conjugation

Answer 1

The Correct Option is D

The question is about identifying which conjugation reaction does not require an activated conjugating agent. Let's explore each of the options:

1. Glucuronidation: This reaction involves the addition of glucuronic acid to a substrate. It typically requires the activation of glucuronic acid to form UDP-glucuronic acid, which acts as the conjugating agent.
2. Sulfation: This process involves the transfer of a sulfate group from an activated sulfate donor known as PAPS (3'-phosphoadenosine-5'-phosphosulfate) to a substrate.
3. Methylation: This reaction involves the transfer of a methyl group from S-adenosylmethionine (SAM) to a substrate. SAM is an activated form of methionine and acts as the conjugating agent.
4. Glutathione conjugation: This conjugation reaction involves the addition of glutathione to a substrate. Glutathione itself acts as the conjugating agent and does not require activation. The enzyme glutathione-S-transferase catalyzes the reaction.

From the above explanations, Glutathione conjugation is the reaction that does not require an activated conjugating agent, as glutathione itself is used directly in its native form without the need for a prior activation step.

Therefore, the correct answer to the question is Glutathione conjugation.