What can be inferred about Protein A if it is released from the lipid bilayer after treatment with a strong ionic detergent?

What can be inferred about Protein A if it is released from the lipid bilayer after treatment with a strong ionic detergent?

• A. It is an integral membrane protein with a stable structure after detergent treatment
• B. It is a peripheral membrane protein
• C. It is an integral membrane protein whose structure is not maintained after treatment with the detergent
• D. It is a peripheral membrane protein that is also resistant to detergent

Answer: (C)

The inference that Protein A is an integral membrane protein whose structure is not maintained after treatment with a strong ionic detergent can be understood by considering the nature of the interactions between integral membrane proteins and the lipid bilayer. Integral membrane proteins are embedded within the lipid bilayer and often have hydrophobic regions that interact strongly with the lipid tails. When treated with a strong ionic detergent, which disrupts lipid-lipid and protein-lipid interactions, these proteins can be solubilized, indicating that they are indeed integral. However, the fact that Protein A is released from the lipid bilayer also suggests that its structure may be compromised; the detergent can denature proteins, leading to the loss of their native conformation. This loss of structure may affect the protein's functionality as well. In contrast, peripheral membrane proteins are usually associated with the bilayer through weaker interactions and can be released with milder treatments; thus, they are not as likely to exhibit the same level of structural instability upon detergent treatment. This context clarifies why the correct inference identifies Protein A as an integral membrane protein whose structure does not survive the harsh conditions imposed by the strong ionic detergent.

The inference that Protein A is an integral membrane protein whose structure is not maintained after treatment with a strong ionic detergent can be understood by considering the nature of the interactions between integral membrane proteins and the lipid bilayer. Integral membrane proteins are embedded within the lipid bilayer and often have hydrophobic regions that interact strongly with the lipid tails.

When treated with a strong ionic detergent, which disrupts lipid-lipid and protein-lipid interactions, these proteins can be solubilized, indicating that they are indeed integral. However, the fact that Protein A is released from the lipid bilayer also suggests that its structure may be compromised; the detergent can denature proteins, leading to the loss of their native conformation. This loss of structure may affect the protein's functionality as well.

In contrast, peripheral membrane proteins are usually associated with the bilayer through weaker interactions and can be released with milder treatments; thus, they are not as likely to exhibit the same level of structural instability upon detergent treatment. This context clarifies why the correct inference identifies Protein A as an integral membrane protein whose structure does not survive the harsh conditions imposed by the strong ionic detergent.