- #1
TytoAlba95
- 132
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- Homework Statement
- -
- Relevant Equations
- -
Please give me clues as to how to solve this question.
The answer provided is (c).
MCQ- Insertion of a protein into a liposome membrane
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Discussion Overview
The discussion revolves around the insertion of a protein into a liposome membrane, specifically addressing a multiple-choice question related to this process. Participants explore concepts of protein reconstitution, membrane permeability, and the implications of charge on protein incorporation.
Discussion Character
- Homework-related
- Exploratory
- Debate/contested
Main Points Raised
- One participant requests clues to solve a question about protein insertion into liposomes, indicating a lack of understanding.
- Another participant suggests defining terms and sharing initial thoughts as a way to engage with the question.
- A participant speculates that "reconstitution" refers to a protein's incorporation into liposomes, proposing that removing a positive charge could facilitate this process due to the lipid bilayer's impermeability to charged species.
- Another participant clarifies that reconstitution involves not only solubility but also the restoration of the protein's three-dimensional shape in solution.
- A participant agrees with the idea of charge affecting reconstitution but cautions against generalizing that a neutral endgroup will always improve incorporation, noting that the bilayer's composition may influence this outcome.
- There is a mention of the positively charged headgroup of DOPC, raising questions about the interactions between like charges in the context of protein insertion.
Areas of Agreement / Disagreement
Participants express varying levels of understanding and propose different interpretations of the reconstitution process. There is no consensus on the implications of charge on protein incorporation, and the discussion remains unresolved regarding the generalizability of the proposed ideas.
Contextual Notes
Participants have not fully defined all terms or clarified assumptions about the protein and liposome interactions, and there is uncertainty regarding the specific conditions under which the proposed ideas hold true.
Please give me clues as to how to solve this question.
The answer provided is (c).
- #2
berkeman
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You've been at the PF long enough to know that you have to show some effort. Since "Relevant Equations" doesn't apply to this type of question, how about you define all of the terms in this question? Then tell us your initial thoughts on how to figure this out...SanjuktaGhosh said:
- #3
TytoAlba95
- 132
- 19
I'm sorry to have broken the code, but it is true that I'm clueless. Okay...I'll still try writing something.
What could reconstitution mean in this context? A protein in a solution with liposomes trying to incorporate itself into their membrane?
Now that I know the correct option and if I think backwards, having the positive charge removed will be beneficial to incorporate the protein. Because lipid bilayer is not permeable to charged species, so a neutral C-terminal followed by a hydrophilic region will easily enter into the membrane.
Am I right?
What could reconstitution mean in this context? A protein in a solution with liposomes trying to incorporate itself into their membrane?
Now that I know the correct option and if I think backwards, having the positive charge removed will be beneficial to incorporate the protein. Because lipid bilayer is not permeable to charged species, so a neutral C-terminal followed by a hydrophilic region will easily enter into the membrane.
Am I right?
- #4
chemisttree
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Proteins are usually purified by precipitation followed by a dissolution step that is referred to as reconstitution. I think it implies not just solubility but a reconstitution of the protein’s 3 dimensional shape in solution.
- #5
chemisttree
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I agree with your answer to a point. The generic schematic of the vesicle bilayer doesn’t allow us to make a sweeping generalization that substitution of a neutral endgroup for the positive endgroup would result in a better reconstitution (meaning a return of protein’s activity here). If we consider the bilayer is composed of DOPC, the most prevalent lipid bilayer component found in animal systems, you will notice the headgroup is positively charged.SanjuktaGhosh said:
And what do we know about like charges?
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