Week 1, Lecture 1: Intro to Protein Structure Flashcards
How are peptide bonds formed?
amino acids through a condensation reaction to generate the primary sequence
what are weak noncovalent interactions btwn AAs?
Hydrophobic interaction, and hydrogen bonds and ionic interactions
what can change the ionization in the R groups, changing enzyme activity?
pH, heat
what are Two most common forms of secondary structures?
alpha helices and beta-sheet
Describe Myoglobin, type of protein and # of helices…
Globular protein, 8
One type secondary structure make what type of protein?
Globular (most compactly folded), NOT fibrous
Proteins that have similar folds often have similar…..
functions
Myoglobin transports O2 to ____ for storage.
mitochondria
Hemoglobin transports O2 from ___ to ___.
lungs to tissues
What are some factors that might cause a protein to unfold?
Oxidative damage, organic solvents, changes in pH, or changes in temperature can cause proteins to denature
Denaturation exposes hydrophobic residues which can then lead to….?
aggregation making the protein insoluble
eg. heinz bodies
Can you name any diseases associated with protein aggregation?
Alzheimers, parkinsons, type II diabetes, cancer
what happens in Prion diseases?
like Creutzfeldt-Jakob disease, proteins exhibit an increase in beta-sheets.
Whats the result of An increase in beta-sheets?
leads to self-association and the formation of amyloid fibers
Molecular chaperones are used by the cell for what?
to prevent the aggregation of misfolded proteins
multiple polypeptide chains?
quaternary structure
hemoglobin has how many alpha and beta chains?
[α(2):β(2)]
tetrameric hemeprotein
Positive cooperativity results in what shape?
sigmoid shaped curve
Is an allosteric modulator that promotes T state?
2,3-bisphosphoglycerate: at high altitudes
BPG levels increase
what kind of posttranslational modifications can alter protein structure and function?
carbohydrate addition, lipid addition, regulation
what happens when there is a decrease in glycosylation?
higher turn over of RBC
what is a glycosylated protein called that can for a large protein aggregate?
advanced glycation end products
Glycosylation of hemoglobin (irreversible) has little effect on function but glycosylation of collagen in the heart results in ???
cardiomyopathy
Sickle cell anemia can be caused by a point mutation converting ____ to ____? what position? what chain?
glutamatic acid to valine at position 6 in β chain resulting in aggregation
