Michaelis-Menten Plot

Michaelis-MentenPlot

Michaelis-MentenPlot

Measurementof the reaction rates is critical in the study if physiological andbiochemical reactions. In most cases, the rate of biochemicalreactions that are catalyzed by enzymes increases with an increase inconcentration of the substrate. However, at higher substrateconcentrations, the reaction rate tends to decrease[ CITATION Dow10 l 1033 ].At very high concentration of substrate, reaction rate asymptotes toa steady-state level, and any further increase in concentration ofthe substrate does not lead to any changes in the rate of reaction.

ExperimentalResults

Table1.0. SampleResults

Cuvette No.

Vol mg/ml BSA

A595 (Corrected)

0

0

0.005

1

10

0.266

2

20

0.418

3

30

0.59

4

40

0.678

5

50

0.791

6

75

1.05

7

100

1.21

Figure1: Regressionof Corrected A595 and Concentration

Michaelis-MentenEquation

TheMichaelis-Menten equation is used to describe the rate of theenzymatic reaction where reaction rate, ʋ, is related to substrateconcentration [S] described by the equation below.

,

CorrelatingLinear Equation with Michaelis-Menten Equation, the

LinearEquation Expression

WhereY is the dependent variable, m is the slope x is the independentvariable and c is the y-intercept.

Fromthe regression curve above, the linear equation is

.

Therefore

Translatingthis to Michaelis-Menten Equation below

Therefore

Thereforesubstituting for the values above,the Michaelis-MentenEquationcan be presented as

Sincethe [S] values are given, then the different values of reaction ratecan be calculated for each of the [S] value given.

Table2: Michaelis-MentenValues

Cuvette No.

Rate of Reaction, v

Vol mg/ml BSA [S]

0

0

0

1

6.371035783

10

2

6.394679818

20

3

6.402600209

30

4

6.406567768

40

5

6.408950664

50

6

6.412130617

75

7

6.413721777

100

Usingthe different substrate concentrations, then the Michaelis-Mentenplot is represented as below

0.5Vmax

Km

At Vmax = 6.4185, Km=0.0745

Figure2: Michaelis-MentenPlot

Discussionand Conclusion

Thetwo major kinetic parameters identified in the figure 2 above areVmaxand Km.Vmaxis a function of intrinsic enzyme rate and total number of enzyme ortransporter for the substrate while Kmrelates inversely to the apparent affinity of enzyme or transporterof the substrate. As a result, low Kmvaluesreflect high interaction affinity between the protein and substratesince it will take very low substrate concentration to reach 50% ofsaturating concentration. From figure 2 above, Km is 0.0744, andthis is considerably very low compared to Vmax, which is 6.4185. Thisis an indication of a high interaction affinity between BSA andProtein Assay Dye.

Reference

Dowd, J., &amp Riggs, D. (2010). A comparison of estimates of Michaelis-Menten kinetic constants from various linear transformations. Journal of Biological Chemistry 240, 863-869.