Use the thermodynamic arguement to explain why the perfectly
folded protein is only marginally stable compared to its unfolded
form.
Use the same equation to explain why higher temperatures
denature proteins.
Which of the weak forces is the most important in the overall
protein stability?
The
hydrophobic effect is the primary driving force for protein folding
because
A) a folded protein maximizes the entropy of water
B) an unfolded protein maximizes the entropy of a biological
system
C) a folded protein is able to form the most hydrogen
bonds
D) hydrogen bonds within the protein replace hydrogen bonds
between the protein and water
Imagine conducting the following experiment. Take a sample of the
native folded peptide and measure the amount of peptide required to
inhibit the activity of a potassium channel, say the Kv4.2 channel,
by 50%. We will call this value the IC50 value. For our peptide,
IC50 = 5 nM for the Kv4.2 channel. Treat the peptide with a mixture
of 2-mercaptoethanol and guanidine hydrochloride. Remove the
2-mercatoethanol and then the guanidine hydrochloride to allow the
peptide to refold. Treat the...
Imagine conducting the following experiment. Take a sample of
the native folded peptide and measure the amount of peptide
required to inhibit the activity of a potassium channel, say the
Kv4.2 channel, by 50%. We will call this value the IC50
value. For our peptide, IC50 = 5 nM for the Kv4.2
channel. Treat the peptide with a mixture of 2-mercaptoethanol and
guanidine hydrochloride. Remove the 2-mercatoethanol and then the
guanidine hydrochloride to allow the peptide to refold. Treat the...
Peptide: YCQKWMWTCDSARKCCEGPVCRPWCKKII
Imagine conducting the following experiment. Take a sample of
the native folded peptide and measure the amount of peptide
required to inhibit the activity of a potassium channel, say the
Kv4.2 channel, by 50%. We will call this value the IC50
value. For our peptide, IC50 = 5 nM for the Kv4.2
channel. Treat the peptide with a mixture of 2-mercaptoethanol and
guanidine hydrochloride. Remove the 2-mercatoethanol and then the
guanidine hydrochloride to allow the peptide to refold....
Develop a hypothesis to explain why albumin in the blood can
serve as a nonspecific carrier for such diverse substances as
bilirubin, calcium ion and fatty acids
. Regarding the folded and unfolded states of a protein (2 pt):
a. Do they have the same peptide bonds? b. Do they have the same
non-covalent interactions? c. Which state has more water-exposed
non-polar side chains? d. Which state has higher enthalpy? Why? e.
Which state has higher entropy if we consider the surrounding water
molecules? Why?
The native and denatured forms of a
protein are generally in equilibrium as follows:
Protein (denatured) <--> Protein
(native)
For a certain solution of the protein ribonuclease A, in which the
total protein concentration is 2.00 x 10-3 M, the
concentrations of the denatured and native proteins at both 25.0°C
and 37.0°C are given in the following table.
Temperature (C°)
[Ribonuclease A (denatured)] (M)
[Ribonuclease A (native)] (M)
25.0
5.10 x 10-6
2.00 x 10-3
37.0
2.80...
1). Where do the hydrophobic amino acid residues usually end up
in a folded protein and why? How does hydrogen bonding play a role
in stabilizing the beta-sheet structure? Where do the R groups then
end up in this structural pattern?
2). Why is the alpha-helix so commonly found? Describe the
structural basis of this conformation.
3). How do amyloid-beta peptides aggregate and eventually cause
Alzheimer's disease? Where do the amyloid-beta peptides come form
(what protein are they from and...