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. 1994 Oct;67(4):1439–1454. doi: 10.1016/S0006-3495(94)80617-4

Stochastic simulation of activation in the G-protein cascade of phototransduction.

T D Lamb 1
PMCID: PMC1225507  PMID: 7819482

Abstract

Activation of the G-protein cascade underlying phototransduction has been modeled by simulating the two-dimensional diffusional interactions that occur at the rod disc membrane between the three reacting protein species, which are the activated rhodopsin (R*), the G-protein (G), and the effector protein (E, the phosphodiesterase, PDE). The stochastic simulations confirm the main predictions of a simplified analytical model (Lamb, T. D., and E. N. Pugh, 1992, Journal of Physiology 449:719-758), and extend that treatment to more complicated cases, where there is a finite probability of reaction or a finite time for reaction. The simulations also provide quantitative estimates of the efficiency of coupling from activated G-protein (G*) to activated effector (E*) in terms of the concentrations, lateral diffusion coefficients, and binding rate constants of the participating molecules; the efficiency of coupling from G* to E* is found to be not as high as in the previous simplified analytical theory. The findings can be extended to other G-protein cascades, provided that the physical parameters of those cascades are specified.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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