Question

Which of the following equation is Eadie-Hofstee plot equation?

(a) \(\frac{1}{V_0} = \frac{K_m}{V_{max}} \frac{1}{[S]}+\frac{1}{V_{max}}\)

(b) \(V_0=\frac{V_{max} [S]}{K_m+[S]}\)

(c) \(V_0=K_m \frac{V_0}{S_0}+V_{max}\)

(d) \(\frac{[S_0]}{V_0} = \frac{1}{V_{max}} [S_0]+\frac{K_m}{V_{max}} \)

The question was posed to me in an interview for job.

My doubt is from Kinetics of Enzyme Catalysed Reaction in section Enzyme Kinetics of Enzyme Technology

Answer 1

Right choice is (c) \(V_0=K_m \frac{V_0}{S_0}+V_{max}\)

Best explanation: The Lineweaver Burk equation has its own limitations due to the following reasons:

The extrapolation of graph to determine the -1/Km reaches the edge of the paper such that, the accurate value is unable to calculate.

The -1/Km value calculated for low substrate concentrations are seemed to be inaccurate for most times.

The linearity of the graph for calculating the -1/Km value is not clear.

To overcome these, Eadie-Hofstee plot equation was designed. The equation is

\(V_0=K_m \frac{V_0}{S_0} + V_{max}\) where,

V0 = initial velocity, Vmax = maximum rate, Km = Miachelis Menten constant and [S] = substrate concentration.