Protein Folding Flashcards
protein folding diagram
funnel shape, lowest entropy at bottom where native state lies
why is same native state always reached
funnel only has one end point, system always collapses to the global minimum
why is native state stable to small environmental changes
free energy of native state increases steeply to rigidity of native state
rate linked to funnel diagram
steeper funnel = quicker folding, smoother curve = less chance of getting stuck in local minima
why during protein folding does protein not probe all local minima
takes shortest path to global minimum
how does rate of protein folding affect funnel diagram
slower protein folding has deeper local minima and higher barriers to overcome
how does RDS in early stages affect funnel diagram
single deep minima with high barrier in upper part
how does a mutation giving distinct states affect funnel diagram
basins of comparable depth
factors that promote protein folding
hydrophobic interactions, intra/intermolecular H-bonds, coulomb potential between ions and covalent disulfide links
denaturation at low temps
weaker hydrophobic interactions, protein structure less stabilised and S term is also temp dependent
self-assemby
spontaneous formation of complex structures of molecules held together by molecular interactions
ampiphile
compound with hydrophobic and lipophilic properties
phospholipids
polar heads and nonpolar tails
micelles
spherical, form above critical micelle conc and above critical temp
liposome
double layer of phospholipids with cavity in middle, with large radius they become bilayers
types of interactions in protein folding
h-bonding between backbone N-H and C=O, hydrophobic interactions between nonpolar side chains
ionic between oppositely charged side chains and van der Waals’ between all atoms
