Enzyme simulation

1
Enzyme simulation
Concentration of substrate
Enzyme kinetics- Rate of enzyme catalysed
reaction is dependent upon
For an enzyme obeying michaelis menten
kinetics VVmaxS Km S
Vmax
V
Michaelis menten describes the initial rate of
reaction of a single substrate with enzyme under
steady state conditions.
S
Concentration of enzyme
The rate of reaction increases linearly as the
concentration of enzyme increases until all
substrate is utilized
Except when EgtgtS
V
E
Null Hypothesis My enzyme has no significant
characteristics
To disprove this I will find the Km and Vmax of
my phosphatase PH/03-434-000 as they are
important kinetic parameters for the
characterisation of my enzyme. I will also asses
the sensitivity of my enzyme to pH.
By spending days in the lab I successfully
disproved my null hypothesis by discovering
individual characteristics of the phosphatase
The values of Km and Vmax can be deirved from my
lineweaver-burke plot (for pH 7.2) Vmax- 1/y
intercept 1/0.102 9.80micro moles/min Km
-1/ x intercept -1/-0.387 2.58mM
Line-weaver burke plot
Kinetic profile

9.8
pH 10
1/V
pH 5.5
V
0.5
Vmax
pH 7.2
0.102
Km
S
2.58
1/s
-0.387
1.0
The pH profile of my enzyme
Possible amino acids in active site
Any deviation from pH optimum results in an
increase in Km but Vmax is constant. Turnover
unaffected by pH Km change shows alterations in
affinity of enzyme for substrate with pH THE
AMINO ACID RESIDUES IN ACTIVE SITE MUST BE pH
SENSITIVE!
Aspartate
7
V (umol/min)
Histidine
Arginine
pH 5 7.2 10