Book of Abstracts: Albany 2005

category image Volume 22
No. 6
June 2005

Fluctuations of the Enzymatic Reaction Rate in the Case of Competing Inhibitor-Enzyme Bounding

The fluctuations of the enzymatic reaction rate in the case of competing bounding of the inhibitor to the enzyme are determined. It is considered that the molecules of the enzyme are immobilized on the carrier that is bounded with the solution containing substrate and inhibitor. Within the solution the substrate and inhibitor are being homogeneously bounded to the enzyme after which the substrate-enzyme and inhibitor-enzyme complexes are dissolving to the free enzyme, product and inhibitor dispatched into the solution. No diffusion limitations are considered.

The processes of inhibitor-enzyme complex formation and its dissolving to the free enzyme and inhibitor are rather fast. The determination of the enzymatic reaction rate fluctuations is equivalent to the calculation of the amount of the substrate-enzyme complex on the carrier taking into consideration probable bounding of the inhibitor to the active locus of the enzyme.

The calculations show that the interdependence between the fluctuations of the enzymatic reaction rate and substrate concentration is linearly in the case of low substrate concentrations. However, higher substrate concentrations result to decrease of fluctuations. The maximum fluctuations occur when the substrate concentration is equal to Michaelis constant. The occurrence of the inhibitor results to the decrease in fluctuations? intensification rate in the case of rather low substrate concentrations as well as to the decrease in fluctuations rate in the case of higher substrate concentrations.

Valery B. Arakelyan1
Emil S. Gevorgyan2, *
Tigran S. Sukiasyan2
Aram E. Gevorgyan3
Anush V.Arakelyan2

1Yerevan Physics Institute
375036 Yerevan, Armenia
2Yerevan State University
Department of Biophysics
375025 Yerevan, Armenia
3Institute of Molecular Biology of National Academy of Sciences of Armenia
*Phone; 3741 556 778
Email: emilgev@freenet.am