Choose a FALSE statement about Hill's plot. All or none binding is given by n = N² (N is the total number of binding sites, n is the number of sites where ligand is fully bound). Hill coefficient can be non-integer O The ends of the curve in Hill's plot can not have slopes greater than unity because they correspond to binding of the first and last ligand molecule to the macromolecule. O when there is no cooperativity n = 1

Choose a FALSE statement about Hill's plot. All or none binding is given by n = N² (N is the total number of binding sites, n is the number of sites where ligand is fully bound). Hill coefficient can be non-integer O The ends of the curve in Hill's plot can not have slopes greater than unity because they correspond to binding of the first and last ligand molecule to the macromolecule. O when there is no cooperativity n = 1

Biochemistry

9th Edition

ISBN:9781319114671

Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Chapter1: Biochemistry: An Evolving Science

Section: Chapter Questions

Problem 1P

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Similar questions

A protein-ligand binding reaction is run. At equilibrium, half the protein is ligand bound, the unboundligand concentration is 0.657 nM. Calculate the koff value for this reaction. Assume the kon value is typical ofprotein-ligand interactions.
The Graph below shows the binding curves of two proteins (A and B) for the same ligand (L). Use this Graph and determine the dissociation constant, K, for both proteins. Which protein (A or B) has a greater affinity for ligand L? Which of the two proteins would be more easily inhibited by an antagonist? 1.0 Y 0.5 2 A 4 6 B 8 [L] (μM) 10 12 14 16
Three different ligands, Ligand Q, Ligand T, and Ligand W, bind to the same protein but with different affinity: The association constant (Ka) for the binding of Ligand Q to the protein is 0.033 nM-1. The fractional saturation (Y) of the protein is 0.20 when the concentration of Ligand T is 1.25 nM. The fractional saturation (Y) of the protein is 0.80 when the concentration of Ligand W is 72 nM. Given this information, Calculate Kd for the binding of each ligand to this protein. Which ligand binds with greatest affinity? Which ligand binds with the lowest affinity?
12 mM of protein A is combined with 6 mM of ligand X in water. After the protein-ligand complex binding reaches equilibrium, you measure that the free ligand concentration is 3 mM and the concentration of protein-ligand complex is 3 mM. What is the Kd for protein A? Although they would be in mM, do not include units in your answer, only the number as a whole integer.
For a binding protein to show positive cooperativity…. Choice 1 of 4:the protein must be able to adopt at least 2 different conformations each with different affinities for the ligand Choice 2 of 4:the protein must be able to bind to at least 2 different types of ligand Choice 3 of 4:the protein must bind to one molecule of ligand fast and one molecule of ligand slowly Choice 4 of 4:the Kd must be in the micromolar range
An engineered ligand binds its target with 5 nM affinity at high pH. However, protonation of a histidine residue in the binding site of the ligand renders it unable to bind. Plot the ligand:target complex concentration versus the initial ligand concentration (in protonated or unprotonated form) at pH 4, 5, 6, 7, or 8 (five lines on one plot). Use a total target concentration of 10 nM.
For the investigation of positive homotropic cooperativity within protein-ligand binding interactions, Hill proposed a reaction as well as a graphic approach. Give the Hill equation as well as a Hill graph and explain the use/meaning of the graph
Give the general Adiar equation for the binding of a ligand to a dimeric protein. Explain further what your understanding is of the terms "no-, positive-, and negative cooperativity” and graphically present the relationship between Ȳ and [S] for each of these cases. Also, give the relationship between the constants Kb1 and Kb2 in each case.
Which of the following statements is right? O For a protein-ligand interaction P +LSP•L, 0 = 0.5 when [L] = Kd. all of the answers are correct Peptide bonds are not weak non-covalent interactions. For an enzymatic reaction that follows Michaelis-Menten kinetics, v/Vmax = 0.5, when [S] = KM. The initial rate of an enzyme catalyzed reaction approaches Vmax, as 1/[S] approaches 0.
Consider the binding reaction L + R → LR, where L is a ligand and R is its receptor. When 1 × 10−3 M of L is added to a solution containing 5 × 10−2 M of R, 90 percent of the L binds to form LR. What is the Keq of this reaction? How will the Keq be affected by the addition of a protein that facilitates (catalyzes) this binding reaction? What is the dissociation equilibrium constant Kd?
Consider the dissociation reaction for a protein-ligand complex: P•L P + L A. Sketch a binding curve (fractional saturation θ vs. ligand concentration [L]) for this protein-ligand complex (ligand A). Show where on that curve you could obtain the dissociation equilibrium constant Kd for the reaction. B. Now sketch on the same axes a θ vs. [L] plot for a different ligand (B) that binds more weakly than the first ligand. C. Does the weaker binding ligand have a higher, or lower, Kd than the tighter binding ligand? D. Sketch a binding curve for a cooperatively bound ligand with K0.5 higher than that of Kd for A or B. (Note: for cooperative binding, each protein molecule would have to have more than 1 binding site for the ligand; K0.5 is the experimentally determined ligand concentration that gives θ = 0.5.)
Which of the following situations would produce a Hill plot with nH < 1.0? Explain your reasoning in each case.(a) The protein has multiple subunits, each with a single ligand-binding site. Binding of ligand to one site decreases the binding affinity of other sites for the ligand.(b) The protein is a single polypeptide with two ligand-binding sites, each having a different affinity for the ligand.(c) The protein is a single polypeptide with a single ligand-binding site. As purified, the protein preparation is heterogeneous, containing some protein molecules that are partially denatured and thus have a lower binding affinity for the ligand.