4 Flashcards
how is hemogolbin described
tetramer or dimer of alpha-beta protomers
what feature makes a structure an oligomer
repeating units
what is the repeating unit in an oligomer
protomer
what are oligomers associated with
a symmetry form
how are errors in translations affected by the quaternary structure
less critical
what is pseudosymmetry
non-identical homologous subunits are related by symmetry
what are the types of symmetry
Cyclic, dihdedral, tetrahedral, octahederal, isocaheadral
describe the axes in Dn
2N protomers arranged around 2 axes
one N fold and one 2 fold
what is helical symmetry
protomers related by rotation and translation
what are the fold axes in tetrahedral symmetry
3 fold and 2 fold
what are the fold axes in octahedreal symmetry
2, 3, 4
what are the fold axes in icosahedral
2, 3, 5
what are the types of forces in protein folding
weak, non covalent
what can destroy the native state of a protein (4)
heat pH detergents organic solvents
what are the two denaturants of interest
guanidinium and urea
descibe the effects of the two denaturants of interest
chaotropic, water soluble, disrupt H-bonding
what are the two reducing agents of interest
beta-mercaptoethanol and DTT (dithiothreitol)
what kind of process is denaturation
cooperative
what is the midpoint of transition for denaturant characteristic of
protein and denaturant
what effect does unfolding part of the protein have on the energy required to unfold the rest of the structure
decreases
what is the state between secondary and tertiary structure
molten globule
what is misfolding
stable structure but not native
what are the disease states leading to misfolding
amyloidosis - huntington’s / alzeimers
prion disease - BSE, scrapie
collagen defects - osteogenesis imperfecta
what 2 things can assist with folding
chaperones or isomerases
