MCB124_ANSWERS_SET3_1-4

MCB124_ANSWERS_SET3_1-4 - MCB 124 Enoch Baldwin ANSWER SET...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
MCB 124 Protein Folding and Stability Enoch Baldwin ANSWER SET 3 page 1 I. PROTEIN STABILITY 1) Name six amino acid types that you might expect to find in a protein core Ala Val Leu Ile Met Phe Cys Also: Pro Trp Tyr 2) Name six that you would more likely find on the surface. Asp Glu Lys His Arg Asn Gln Ser Thr 3) Name two that would be reasonable in either place. Gly Pro Ala Also: Tyr Cys Trp Met -these residues have some polar character and are often at partially buried positions. 2. Mutational Effects on Stability or each of the below substitutions a) predict their effects on the free energies of the folded (F) and unfolded state (U) (use "-" for a favorable change, "+" for an unfavorable change) b) for each state briefly explain why, and c) predict the overall change in stability (use same convention as for (a)) and why? 1) Surface Leu ± Ala F - why? less hydrophobic surface area exposed to solvent U - why?_ less hydrophobic surface area exposed to solvent Overall __0 why? _ no change in environment of residue, equal stability change for both folded and unfolded 2) Buried Leu ± Ala F + why? creation of internal cavity and loss of vanderwaals interactions U - why? ____less hydrophobic surface area exposed to solvent Overall + why? folded state destabilized, unfolded state stabilized 3) Surface Leu ± Lys F - why?_ less hydrophobic surface area exposed to solvent, greater charge increases solubility U - why? less hydrophobic surface area exposed to solvent, greater charge increases solubility Overall 0 why? no change in environment of residue, equal stability change for both folded and unfolded 4) Buried Asp ± His F 0 why? both residue types are charged-change only if involved in specific interaction U 0 why? both residue types are charged-change only if involved in specific interaction Overall 0 why? equal stability change for both folded and unfolded 5) Surface Helix Ala ± Gly F 0/+ why? _Gly has a very low "helix" propensity U - why? flexibility (entropy) of unfolded state increased Overall + why? folded state destabilized, unfolded state stabilized
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
MCB 124 Protein Folding and Stability Enoch Baldwin ANSWER SET 3
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 5

MCB124_ANSWERS_SET3_1-4 - MCB 124 Enoch Baldwin ANSWER SET...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online