Comparative stabilization of biological photosystems by several immobilization procedures

Cocquempot, M. F.; Thomasset, Brigitte; Barbotin, Jean‐Noël; Gellf, G.; Thomas, Daniel

doi:10.1007/bf00505866

Cited by 64 publications

(15 citation statements)

References 30 publications

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“…3A, the experimentally measured initial rate (12) increases with DCPlPox concentrations, .4. :iccording to an hyperbolic law. Furthcrmore, the higher the intensity, the higher thc maximal activity and half-saturation concentration.…”

Section: C'lowd C~mriitions Without Uhsorhutzwmentioning

confidence: 91%

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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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Section: C'lowd C~mriitions Without Uhsorhutzwmentioning

confidence: 91%

“…Immnbilized thylakoids wcre illuminated perpendicularly with an incandescent halogen lamp (100 W, 12 V, Spindler and Hoyer, K.G.). Light intensities were measured with a Kipp and Zonen pyranometer (CM 10 Solari meter).…”

Section: Evporimmtu1 Devicementioning

confidence: 99%

Experimental evidence for multistability in a photobiochemical system

1985

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“…In an earlier work (Papageorgiou 1983) we have shown that isolated higher plant chloroplasts with intact envelope membranes (intact chloroplasts) can be immobilized by covalent bonding in the glutaraldehyde crosslinked albumin matrix, described initially by Broun et al (1973) and then applied to higher plant thylakoids by Cocquempot et al (1979Cocquempot et al ( , 1981 ; see also review by Barbotin et al 1985). In the present work, we investigate the conditions for covalent entrapment of photosynthetically active cyanobacteria in the same matrix, and we examine several stability indices of the immobilized cells.…”

Section: Introductionmentioning

confidence: 96%

Immobilization of photosynthetically active cyanobacteria in glutaraldehyde-crosslinked albumin matrix

Papageorgiou

Lagoyanni

1986

Appl Microbiol Biotechnol

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Summary. Cryoprotection was afforded to cells ofPhormidium luridum and Anacystis nidulans by preloading them with dimethyl sulphoxide and then performing the immobilization reaction in dimethyl sulphoxide-free medium. Compared with free cyanobacteria cells, matrix-immobilized cyanobacteria exhibit superior temperature tolerance and storage longevity of photoinduced electron transport, while their phycobiliproteins are better protected against thermal denaturation. Photosynthetically active Phormidium spheroplasts capable of interacting with ionic Hill cofactors, were immobilized in crosslinked albumin matrix, with cryoprotection provided by sorbitol.

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“…One chemical immobilization method, which compares favorably with others with respect to several stabilization indices, is the covalent entrapment of biological materials within a crosslinked protein matrix formed by deep freezing and then slowly rewarming a mixture of bovine serum albumin and glutaraldehyde. The method, originally developed by Broun et al (1973) has been applied, so far, only to preparations of envelope-free thylakoids (Cocquempot et al, 1979; and to isolated bacterial chromatophores (Cocquempot et al, 1981 b;Larreta-Garde et al, 1981). Under the scanning electron microscope, the matrix appears as a network of homogeneous sheets having threadlike structures on their surface.…”

Section: Introductionmentioning

confidence: 99%

“…Under the scanning electron microscope, the matrix appears as a network of homogeneous sheets having threadlike structures on their surface. Grana fragments, organelles, and cells are attached to these sheets with apparently intact morphology (Barbotin and Thomasset, 1981).…”

Section: Introductionmentioning

confidence: 99%