DD - Ligand Binding 2 Flashcards
What are the general axis of a scatchard plot?
Y-axis- Ratio of bound ligand to free ligand
X-axis- Bound ligand
What do scatchard plots help determine?
The affinity of the receptor for its ligand and the number of binding sites
How do you calculate Kd from a scatchard plot?
The gradient is -1/Kd
Rearrange for Kd
When given ‘total bound’ and ‘non specific binding’ data values, what must be done to successfuly complete a scatchard plot?
Total bound - Non specific binding = CORRECTED Total bound
Corrected bound / Ligand : Y-axis
Corrected bound : X-axis
What is the structure of Myoglobin? (2)
- A monomeric protein found in the muscle
- Bound Fe 2+ as part of the haem group
What is the function of myoglobin?
The primary oxygen-carrying pigment in muscle tissue
What is the formula for fractional occupancy?
f =
Concentration of the complex /
Total protein concentration
What is the structure of heamoglobin?
Made of 4 subunits (2 alpha and 2 beta chains)
Haem group binds to O2
What 2 states does haemoglobin exist in?
- Oxy-haemoglobin- 4 O2 bound (R-state)
- Deoxy-haemoglobin- 0 O2 bound (T-state)
What type of curve is shown for the binding of myoglobin and the binding of haemoglobin?
Myoglobin- Rectangular Hyperbolic
Haemoglobin- Sigmoidal
What does the hill equation describe?
The binding of n molecules of O2 to haemoglobin
Does the hill equation indicate the number of binding sites?
NO- Indicates the degree of cooperativity
How can the hill coefficient be used to quantify the degree of cooperativity?
n = 1 (No Cooperativity)
n > 1 (+ Cooperativity)
n < 1 (- Cooperativity)
