Lecture 6 Protein Folding 1 Flashcards
The A.A. Gly is embedded where? on which polypeptide?
Inside the tightly packed with in the triple helix of Collagen.
The Heptad is a repeating alpha helical sequence of which polypeptide?
Alpha Keratin
Collagen and Keratin are made up of what handed Alpha helices? respectively
Left and Right handed
For the wrapping of the multiple Alpha helixes together in Collagen and keratin, which handness are they wrapped? respectively
Right and Left handed
Which of collagen or Keratin is know as coiled coil structure? triple helix?
Keratin
collagen
Which residue to repsponsible for Holding the coiled coil together? and how often is this residue repeating on the chain?
Leu-leu on adjacted polypeptides
7th residue
Why is Leucine good for internal positioning
its hydrophobic
What are some obligatory amino acids? whats this mean?
Acidic and Basic (other than His) are charged at physiological ph and will pair with opposited charges on adjacent chains. and will repel like charges
Alpha helices Hydrogen bonds and R groups are located where in relation to the helix?
R groups, point out from the Helix
H bonds run parallel to the helix between the polypeptide backbones.
Collagens repeated sequence and how often?
X - Pro - Gly, every 3
What are the 4 major types of bonding in tertiary structure that creates folding?
Mainly know its ALWAYS BETWEEN R GROUPS.
- H bonding 2. Ionic bonds 3. hydrophobic interactions
- disulfide - covalent bonds of Cysteine’s sulfur atoms
Protein Folding is a highly ________ process?
cooperative
for hydrophobic effect, non polar A.A. come together b/c?
The entropy in breaking the crystal lattice H bonds of water around the Hydrophobic entities, this provides the energy for folding.
Folding funnel - Highly cooperative first 3 steps of the folding process to form a molten globule occurs at what pace? and driven by what? test question!
Happens in milliseconds and driven by hydrophobic effect.
The the final step or two, to get native structure could take longer.
Gibbs free energy of Hydrobic effect.. how is folding favorable and what are the H and TS terms signed?
the hydrophobic effect, is the folding of proteins, the folded protein are -S and + H, both less spotaneous and requires heat Makes sense b/c its forming something and using energy. alone it is +G, un favorable, but the solvent is the exact opposite and providing of the E for folding.
