MBOD - Three dimensional structure of proteins
Home > Preview
The flashcards below were created by user
on FreezingBlue Flashcards.
What is the secondary structure of a protein?
- The organization of primary structural features.
- Alpha helices and beta sheets
What is the tertiary structure of a protein?
Steric relationships of AA's that may be far apart in AA sequence
What is quaternary structure of a protein?
Mode of association between two or more polypeptide chains
How are the six atoms in an AA oriented?
Coplanar. This is due to resonance.
Does the alpha carbon in a peptide bond lie cis or trans to a C-N bond?
What is the vertical rise for each AA residue in an alpha helix?
- 1.5 angstroms.
- There are 3.6 resudes per turn.
- Each residue gives 100 degrees of separation.
What is an alpha helix stabalized by?
Hydrogen bonds between carboxyl and amino groups
What is a very common "open" motif that can have parallel or antiparallel configurations, and is stabilized by hydrogen bonding?
What residues favor formation of alpha helix?
Met, Glu, Leu, Ala, Gln
Which residues favor formation of beta sheets?
Val, Ile, Phe, Tyr
In a membrane integral protein that forms a water pore, where would charged residues be found? Where would hydrophobic residues be found?
- Charged - in the center of the pore
- Hydrophobic - on the outside of the pore
How can water soluble enzymes be associated with membranes?
Post translational modifications with hydrophobic groups
Whis is a disulfide bridge?
- Oxidative cross binding of cysteine residues.
- Sulfhydryl groups giving up electrons (H) to bind to another sulfhydryl group that has lost an electron
Describe the residues of intrinsically unstructured proteins.
Many charged residues. Also very polar.
What does PDI do?
Catalyzes disulfide exchange reactions
What does PPI do?
Catalyzes interconversion of cis to trans configuration in peptide bonds. (Trans is normal)
What do molecular chaperones do?
Bind to hydrophobic portions of a protein and keep them from aggregating and folding.
What is a contiguous portion of a polypeptide chain that folds independently into 3d structures?
What does Cystic Fibrosis result from?
F508X mutation in CFTR. This results in improper folding of chloride transport protein.
What would you like to do?
Home > Flashcards > Print Preview