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Experimental data are from the author's laboratory, showing the kinetics of HIV-1 protease. For experimental details see the reference below.

Experimental data and postulated reaction mechanism:

Least squares fit and optimized rate constants:

Reaction Mechanism

The chemical system analyzed in here is described by the following reaction mechanism:

Differential Equations

The changes in concentrations of chemical species over time are computed by solving and initial value problem described by the following system of differential equations:

d[M]/dt= -km[M]-km[M]+kd[E]+kd[E]
d[E]/dt= +km[M][M]-kd[E]-ka[E][S]+kr[ES]
d[S]/dt= -ka[E][S]
d[ES]/dt= +ka[E][S]-kr[ES]
d[P]/dt= +kr[ES]

Importantly, the investigator does not need specify these fitting equations in the mathematical form. Instead, the theoretical model is entered in a symbolic format as follows:
[mechanism]
   M + M <==> E     : km  kd
   E + S --> ES     : ka    
   ES --> E + P     : kr

[constants]
   km = 0.92, kd = 0.0019
   ka  = 10 ?, kr = 10 ?
The computer automaticaly derives the fitting equations from the text above. Rate constants identified with the question mark are optimized to achieve best least-squares fit.


Reference:

"Mechanical effects on the kinetics of the HIV proteinase deactivation."
Kuzmic, P.; Peranteau, A.G.; Garcia-Echeverria, G.; and Rich, D.H. (1996) Biochem. Biophys. Res. Commun. 221, 313-7.


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