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BIOMD0000000283 - Chance1943_Peroxidase_ES_Kinetics

 

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Reference Publication
Publication ID: 10218104
Chance B.
The kinetics of the enzyme-substrate compound of peroxidase. 1943.
Adv. Enzymol. Relat. Areas Mol. Biol. 1999; 73: 3-23
Johnson Research Foundation, University of Pennsylvania, Philadelphia.  [more]
Model
Original Model: BIOMD0000000283.xml.origin
Submitter: Kieran Smallbone
Submission ID: MODEL1010190000
Submission Date: 19 Oct 2010 11:28:01 UTC
Last Modification Date: 07 Apr 2014 01:31:17 UTC
Creation Date: 10 Oct 2010 10:10:10 UTC
Encoders:  Lukas Endler
   Kieran Smallbone
set #1
bqbiol:hasVersion Gene Ontology regulation of catalytic activity
Gene Ontology peroxidase activity
set #2
bqbiol:hasTaxon Taxonomy Armoracia rusticana
Notes

Default parameter values are those in the right hand panel of Fig 12. The other panels may be obtained by setting X to 1, 2 or 4, and K3 to 0, 1/2 or 1.

This model is described in:
The kinetics of the enzyme-substrate compound of peroxidase.
Britton Chance, Journal of Biological Chemistry, 151, 553-577, 1943. PDF at JBC
reprinted in: Adv Enzymol Relat Areas Mol Biol. 1999;73:3-23. PubmedID:10218104>
Abstract:
Under the narrow range of experimental conditions, and at a temperature of approximately 25 degrees, the following data were obtained. 1. The equilibrium constant of peroxidase and hydrogen peroxide has a minimum value of 2 x 10(-8). 2. The velocity constant for the formation of peroxidase-H2O2 Complex I is 1.2 x 10(7) liter mole-1 sec.-1, +/- 0.4 x 10(7). 3. The velocity constant for the reversible breakdown of peroxidase-H2O2 Complex I is a negligible factor in the enzyme-substrate kinetics and is calculated to be less than 0.2 sec.-1. 4. The velocity constant, k3, for the enzymatic breakdown of peroxidase-H2O2 Complex I varies from nearly zero to higher than 5 sec.-1, depending upon the acceptor and its concentration. The quotient of k3 and the leucomalachite green concentration is 3.0 x 10(4) liter mole-1 sec.-1. For ascorbic acid this has a value of 1.8 x 10(5) liter mole-1 sec.-1. 5. For a particular acceptor concentration, k3 is determined solely from the enzyme-substrate kinetics and is found to be 4.2 sec.-1. 6. For the same conditions, k3 is determined from a simple relationship derived from mathematical solutions of the Michaelis theory and is found to be 5.2 sec.-1. 7. For the same conditions, k3 is determined from the over-all enzyme action and is found to be 5.1 sec.-1. 8. The Michaelis constant determined from kinetic data alone is found to be 0.44 x 10(-6). 9. The Michaelis constant determined from steady state measurements is found to be 0.41 x 10(-6). 10. The Michaelis constant determined from measurement of the overall enzyme reaction is found to be 0.50 x 10(-6). 11. The kinetics of the enzyme-substrate compound closely agree with mathematical solutions of an extension of the Michaelis theory obtained for experimental values of concentrations and reaction velocity constants. 12. The adequacy of the criteria by which experiment and theory were correlated has been examined critically and the mathematical solutions have been found to be sensitive to variations in the experimental conditions. 13. The critical features of the enzyme-substrate kinetics are Pmax, and curve shape, rather than t1/2. t1/2 serves as a simple measure of dx/dt. 14. A second order combination of enzyme and substrate to form the enzyme-substrate compound, followed by a first order breakdown of the compound, describes the activity of peroxidase for a particular acceptor concentration. 15. The kinetic data indicate a bimolecular combination of acceptor and enzyme-substrate compound.

This model is the one described in the appendix of the article. It reproduces, amongst others, figure 12. The parameters and concentrations used are rescaled as stated in the article. K2 and K3 stand for k2 and k3, respectively, divided by k1.

Model
Publication ID: 10218104 Submission Date: 19 Oct 2010 11:28:01 UTC Last Modification Date: 07 Apr 2014 01:31:17 UTC Creation Date: 10 Oct 2010 10:10:10 UTC
Mathematical expressions
Reactions
r1 r2    
Physical entities
Compartments Species
cell X E P
Q    
Global parameters
K2 K3    
Reactions (2)
 
 r1 [X] + [E] ↔ [P];  
 
 r2 [P] → [E] + [Q];  
 
 cell Spatial dimensions: 3.0  Compartment size: 1.0
 
 X
Compartment: cell
Initial concentration: 8.0
 
 E
Compartment: cell
Initial concentration: 1.0
 
 P
Compartment: cell
Initial concentration: 0.0
 
 Q
Compartment: cell
Initial concentration: 0.0
 
Global Parameters (2)
 
   K2
Constant
 
   K3
Value: 0.5   (Units: dimensionless)
Constant
 
Representative curation result(s)
Representative curation result(s) of BIOMD0000000283

Curator's comment: (updated: 24 Nov 2010 23:14:22 GMT)

Reproduction of the results shown in the second graph from the left, bottom row of figure 12 of the original publication. The results were produced using SBML ODEsolver.

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