affinity and Kinetics

Question 1

What is the affinity of an antibody for its antigen

Answer 1

is how strong antibody-antigen binds

Question 2

what is affinity

Answer 2

is a binding strength of antigen to one binding site of antibody

Question 3

what is kinetics

Answer 3

is a speed whereby antibody-antigen complex form and dissociates

Question 4

what is avidity

Answer 4

is a combined strength of interaction on an antigen with binding sites of antibody

Question 5

why do we analyse affinity and kinetic

Answer 5

• to understand function of antibody
  -to optimize choice and design of antibody for assay

Question 6

what is EC50/ half time effect concentration

Answer 6

refers to the concentration of substance induce response halfway between baseline to the maximum

Question 7

can the same affinity be reached by antibodies with different kinetic properties

Answer 7

yes

Question 8

what is Biosensor

Answer 8

is condition where short half life is favoured to obtain fast response

Question 9

what is therapeutic activity

Answer 9

is when long half life is favoured for sustained biological activity

Question 10

how is Affinity relates to function in vitro

Answer 10

high affinity is favoured for therapeutical uses

Question 11

what is the benefit of high affinity of antibody

Answer 11

• enable antibody to remains on its target
• enable slow dissociation which results in more tumor irradiation

Question 12

how to determine affinity

Answer 12

• equilibrium dialysis: suitable for small molecular weight antigen (heptan)
• QCM-d: voltage is applied across crystal. measurement is made in real time
• Surface plasmon resonance (SPR) (Biacore): make it possible to study molecular interaction without labeling any of participating substances.
• Isothermal titration calorimetry

Question 13

how do you the amount of free antigen using equilibrium dialysis

Answer 13

you mix known amount of antibody and known amount of antigen together.
then some antigen will bind to the surface site of antibody
then you can measure and determine amount of of free antigen
affinity and number of binding site is determined by Scatchard plot

Question 14

what do we know, can calculate and measure in equilibrium dialysis

Answer 14

we know: amount of antigen and antibody
we can measure: amount of free antigen
we can calculate: number of bound antigen

Question 15

what is the application of Isothermal titration calorimetry (ITC)

Answer 15

on carbohydrate binding protein

Question 16

what is the application of QCM-d

Answer 16

• measure frequency, because when protein bound to the crystal mass change as well as frequency. so frequency before and after binding analyte is measures

Question 17

what is the application of Surface plasmon resonance (SPR)

Answer 17

• determine affinity and rate constant
• determine entropy and enthalpy of the reaction

Question 18

up