The correct answer is option 1. Presence of hydrophobic surfaces
Of the factors listed, the following can disrupt the native state of a protein:
1. Presence of hydrophobic surfaces: Proteins often fold into specific three-dimensional structures to shield hydrophobic amino acid residues from surrounding water molecules. However, if there are exposed hydrophobic surfaces in the protein's environment, they can interact unfavorably with water, leading to protein unfolding or aggregation.
The other factors listed can also disrupt the native state of a protein:
2. Removal of water: Water molecules play a crucial role in maintaining the native structure of proteins by mediating hydrophobic interactions and stabilizing folded conformations. Removal of water can disrupt these interactions, causing protein denaturation or aggregation.
3. pH: Changes in pH can alter the charge distribution on amino acid residues within a protein, affecting electrostatic interactions and disrupting the protein's native structure. Proteins typically have specific pH ranges where they are most stable, and deviations from this pH range can lead to denaturation.
4. Temperature: Proteins are sensitive to changes in temperature. Increasing temperature can disrupt the weak interactions (e.g., hydrogen bonds, hydrophobic interactions) that stabilize the protein's native structure, leading to denaturation or unfolding. Conversely, lowering temperature can also affect protein stability, potentially decreasing flexibility or causing freezing-induced damage.
In summary, all of the factors listed—presence of hydrophobic surfaces, removal of water, pH changes, and temperature fluctuations—can disrupt the native state of a protein by interfering with the interactions that stabilize its structure. |
