Proteins <33333 Flashcards
formation of a peptide bond is a ____reaction
condensation
hydrolysis is ________ favorable
thermodynamically
hydrolysis is ______ slow
kinetically
the peptide bond has ______ character
double bond
preparative def
produces a large amount of protein and maintains protein activity
analytical def
usually takes a small amount of protein and that protein is modified or destroyed in analysis
preparative methods
precipitation + column chromatography
analytical methods
gel electrophoresis
solubility is #1 affected by
pH
solubility is #2 affected by
ions
cation exchange
carries - negative charge so + proteins can attach
anion exchange
carries + charge so - charged proteins can attach
elution in ion exchange
salt or change pH
elution of affinity chromatography
change pH to change charge on ligand or competitive binding of similar molecule
total activity
total unites of activity (protein of interest) in a sample
specific activity
unites of activity/amount of protein in sample
fold purification (up to step N)
SAn/SA1
fold-purification (of step N alone)
SAn/SAn-1
% yield
(total activityn/total activity 1) x 100
sds point
denatures protein to make linear and negative
is sds-page analytical or prep?
sds is analytical
1 residue
110 Da
sanger’s method
determine identity of N-terminal residue
edman degradation
used to determine 20-30 n-terminal residues
Trypsin cleav pts
Lys, arg (c)
Chymotrypsin cleav pts
Phe, trp, tyr (c)
Cyanogen bromide
Met (c)
beta mercaptoethanol and dtt
reduces disulfide bonds
