Question

Penicillin is hydrolyzed and thereby rendered inactive by the enzyme penicillinase (also known as b-lactamase), an enzyme present is some antibiotic-resistant bacteria. The amount of penicillin hydrolyzed in 1 minute in a 10 mL solution containing 10^-9 g of penicillinase was measured as a function of the concentration of penicillin. Assuming that the concentration of penicillin does not change appreciably during the assay, make a Michaelis-Menten plot and estimate K_M and V_max.

[Penicillin]0 (mM)	Amount hydrolyzed (nanomoles)
1	0.11
3	0.25
5	0.34
10	0.45
30	0.58
50	0.61

Answer 1

The MM plot is as follows: 0.7 0.6 0.5 0.4 0.3 0.2 S 0.1 20 [Penicillin]0 (mM) 40 60 The data to plot LB is as follows (inverse the given data) Penicilin]o VAmount (mM) 1.000 0.333 0.200 0.100 0.033 0.020 hydrolyzed (nanomoles) 9.09 4.00 2.94 2.22 1.72 1.64

The calculation of Vmax and Xmis as follows: y = 7.6225x + 1.4602 So, when x =0 x 1.4602 max 1.46012 Thus, Van of the enzyme is 0.68 The calculation of (Km) is as follows: y = 7.6225x + 1.4602 So, when y =0 1 7.6225 Km 1.4602 x= - = 5。22 Thus, the value of Kis 5.22mM