Memory in enzyme membranes

Naparstek, Avraham; Romette, Jean‐Louis; Kernevez, J. P.; Thomas, Daniel

doi:10.1038/249490a0

Cited by 77 publications

(23 citation statements)

References 8 publications

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“…The uric acid and oxygen diffused to the membrane from external solution. Earlier the effect of uric acid concentration hysteresis was found in this system (Naparstek et al 1974).…”

Section: Description Of the Modelmentioning

confidence: 98%

“…The uric acid oxidation reaction, being catalyzed by uricase enzyme, has been selected as a biochemical dynamical process. This reaction uricase CsHsOaN 4 + 0 2 , CaH603N 4 + CO 2 (1) 54 that preceeds under excess of oxygen, is inhibited by the excess of uric acid (inhibition by excess substrate) (Naparstek et al 1974). The reaction (1) was studied in the variant of one-box structure (Naparstek et al 1974).…”

Section: Description Of the Modelmentioning

confidence: 99%

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Nonlinear dynamics of the distributed biochemical systems functioning in the dissipative structure formation mode

Sidelnikov¹,

Gritsenko²,

Simonova³

et al. 1992

Biol. Cybern.

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Abstract. Nonlinear dynamical biomolecular systems can evidently be considered as prototypes of information processing devices at molecular level capable to solve problems of high computational complexity. Keeping in mind this goal the dynamics of biochemical system based on enzymatic oxidation of uric acid was considered. The system was studied in the version of distributed biomolecular structure having predetermined geometry of enzyme distribution on a porous planar medium. Being in the regime of stepwise dissipative structure formation this system demonstrated complicated modes of behaviour.

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“…The uric acid and oxygen diffused to the membrane from external solution. Earlier the effect of uric acid concentration hysteresis was found in this system (Naparstek et al 1974).…”

Section: Description Of the Modelmentioning

confidence: 98%

Section: Description Of the Modelmentioning

confidence: 99%

Nonlinear dynamics of the distributed biochemical systems functioning in the dissipative structure formation mode

Sidelnikov¹,

Gritsenko²,

Simonova³

et al. 1992

Biol. Cybern.

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“…Periodic behavior and instability are induced only by changes in the activity caused by microenvironmental effects and correlated diffusion limitation [214,333,334]. Different kinetic models for passive transport, carrier transport, and active transport which take into account explicitly the interrelation between conformational states of the structural units of the membrane and the related transport properties have been derived by HILL and KEDEM [119,120].…”

Section: Examples and Modelsmentioning

confidence: 99%

Physicochemical Fundamentals and Thermodynamics of the Membrane Transport of Drugs

Scheler¹,

Blanck²,

Kahrig³

et al. 1977

Kinetics of Drug Action

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“…This behaviour can be easily explained by considering the combination of the purely photoassisted reaction with the modulation of the intensity of light traversing the solution. In an idealized case, the absorption of a monochromatic radiant energy is governed by the wellknown Bouguer-Lambert-Beer law: ( 2) in which I: is the effective absorption coefficient, . w is the thickness of the solution traversed, and A is the concentration of the light-absorbing molecule.…”

Section: C'lowd C~mriitions Without Uhsorhutzwmentioning

confidence: 99%

Experimental evidence for multistability in a photobiochemical system

1985

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The kinetic behavior of a typical Hill reaction catalyzed by thylakoids and using the oxidized form of 2,6-dichloroindophenol (DCPIPox) as the artificial clectron acceptor, is considered. Here, the light absorption process and the reduction of DCPlPox are autocatalytically coupled, leading to the occurrence of rnultiplc steady states with respect to either the acceptor concentration or the incident light intensity. Experimental evidence is prescntcd for both cases and the emergence of autocatalysis is discussed. The effect of the spatial arrangment on the global behavior of the system described is emphasized.Biocatalytic reactions have bcen studied almost enlerely from the viewpoint of their time-dependent behavior. Rcccntly, a more relevant and realistic approach has consisted of coupling purely catalytic functions with various phenomena intrinsically linked to space, such as diffusion, partition of metabolites, vectorial processes and convection. When autocatalytic reactions are considered, qualitatively different behavior of the system has been predicted theoretically, for example multistability and/or spatiotcniporal structure formation [I]. Experimental evidence of multistability for either ki nctic or electrochemical memory in diffusion-reaction coupled and reconstitutcd enzyme systems has been reported [2 -51. Nevertheless, in the framework of this spatiotemporal concept, littlc attention has been paid to radiation phenomena which, likc diffusion. are also essentially space-dependent and whose role is fundamental in numerous chemical and biochemical processes. A thorough theoretical analysis considcring a simple photodependent isomerization reaction in which one of the isomers absorbs light and restores this energy to the system in the form of heat, was published by Nitzan et al. 16, 71. Here, the light absorption process and the increase of the system's temperature become autocatalytically coupled, leading to the occurrence of multiple steady states and hysteresis. The latter predictions have been experimentally confirmed in the case of the N 0 2 / N 2 0 4 dissociation reaction [8] and more recently in the S03F/S206F2 system [9]. As far as we are aware, no experimental examination of the phenomena pertaining the biological photoreactions has been yet attemped.In the present work, chloroplast thylakoids are immobilized [lo-121 in an artificial membrane lying on the bottom of a reactor fed with DCPIPox as the electron acceptor. The DCPl Pox species adsorbs strongly within the range of illumi- Ahhrc~viutions. DCPIPox, oxidized form of the 2,6-dichloroindophenol. nation wavelengths. Under such conditions we show that thc association between the purely photoassisted reduction of the DCPIPox, and its absorption by light intensity in the range of 600 -800 nm, leads to the appearance of an autocatalytic effect in the rate of reaction. More precisely, the yield of the photoreaction first increases and then decreases. as the DCPIPox concentration increases. The coupling of this nonlinear reaction term with a tra...

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Memory in enzyme membranes

Cited by 77 publications

References 8 publications

Nonlinear dynamics of the distributed biochemical systems functioning in the dissipative structure formation mode

Nonlinear dynamics of the distributed biochemical systems functioning in the dissipative structure formation mode

Physicochemical Fundamentals and Thermodynamics of the Membrane Transport of Drugs

Experimental evidence for multistability in a photobiochemical system

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