Bluelight-induced, flavin-mediated transport of redox equivalents across artificial bilayer membranes

Schmidt, Werner

doi:10.1007/bf01868936

Cited by 19 publications

(4 citation statements)

References 57 publications

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“…Fritz and Ninnemann, 1984;Shimidzu et al, 1979). Singlet oxygen is formed from many excited photoactive pigments including flavins (Presti, 1983;Heelis, 1982/83;Schmidt, 1984a), and in most cases its mode of action is destructive (Elstner, 1982). However, only a few authors have reported that singlet oxygen participates in the regulation of biological processes and reactions dependent on blue light (Nultsch and Wenderoth, 1983;Imbrie and Murphy, 1984a,b;Fritz and Ninnemann, 1985).…”

Section: Discussionmentioning

confidence: 99%

BLUE LIGHT INDUCED, REVERSIBLE IN ACTIVATION OF THE TONOPLAST‐TYPE H+‐ATPase FROM CORN COLEOPTILES IN THE PRESENCE OF FLAVINS

Krauß

Schiebel

Eberl

et al. 1987

Photochem & Photobiology

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Abstract— Irradiation (λmax 447 nm; 58.5 W m‐2) of a microsomal membrane fraction of corn coleoptiles for 5 min in the presence of the in vivo concentration of riboflavin inactivates the tonoplast‐type H+‐ATPase. This inhibition is O2‐dependent, is enhanced in D2O and suppressed by NaN3, indicating participation of singlet molecular oxygen in the inactivating mechanism. Besides singlet oxygen, the superoxide anion (O2‐) is generated during irradiation, which obviously has no effect on the H+‐pumping activity. However, in the presence of superoxide dismutase (SOD), O2‐ is transformed into H2O2 which causes an additional strong inhibition of H+. ATPase activity. This inhibition can be increased by ethylenediaminetetraacetic acid (EDTA), which is known to be an electron donor of the excited flavin molecule. In contrast, catalase prevents the H2O2‐mediated photoinactivation of the H+ ‐ATPase. The light dependent inactivation of H+‐transport does not occur if reduced glutathion (GSH) is added prior to or after irradiation. These results indicate that the blue light mediated inhibition of the H+‐ATPase is mediated by singlet oxygen and H2O2 which oxidize essential SH‐groups of the enzyme into disulfides. Reduction of the formed disulfides by GSH restores the activity of the enzyme.

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Section: Discussionmentioning

confidence: 99%

BLUE LIGHT INDUCED, REVERSIBLE IN ACTIVATION OF THE TONOPLAST‐TYPE H+‐ATPase FROM CORN COLEOPTILES IN THE PRESENCE OF FLAVINS

Krauß

Schiebel

Eberl

et al. 1987

Photochem & Photobiology

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“…02highly unstable in water (Sawyer et al, 1981) is stabilized by aprotic media and particularly paraffins (Brezina et af., 1973;Sawyer et al, 1981). It is sufficiently lipid soluble and stable to cross the bimolecular membranes (Schmidt, 1984;Rumyantseva ef al., 1979). If 02-, formed in the interphase, translocates the bilayer instead of escaping into the aqueous phase, then a current occurs.…”

Section: Discussionmentioning

confidence: 99%

ELECTRON AND PROTON PHOTOTRANSPORTS IN A BILAYER MEMBRANE. ACIDIC PORPHYRIN AND SUPEROXIDE ION AS ΔpH SENSITIVE CHARGE CARRIERS

Hofmanová

Bienvenue²,

Seta³

et al. 1986

Photochem & Photobiology

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Abstract— Glycerolmonooleate planar bilayer membranes containing a zinc‐mesotetraphenyl l‐[3‐propionic acid] porphyrin separate two buffered aqueous phases, an oxidizing and a reducing one. Under illumination stationary photocurrents are recorded, that depend on the respective acidities of the aqueous phases. A strong enhancement is observed when the oxidizing solution is more acidic than the reducing solution. This phenomenon is attributed to the double role of the acidic porphyrin acting as an electron and a proton carrier. A second mechanism, also pH dependent, intervenes concurrently. The excited zinc‐porphyrin reduces oxygen and the resulting superoxide ion translocates through the membrane lipidic core.

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“…However, the properties of flavins do not exclude their excited molecules from functioning within the membrane. For instance, an amphiphilic flavin derivative embedded into an artificial lipid membrane was shown to photocatalyze the translocation of redox equivalents across the membrane [79]. …”

Section: The Environmental Framework For a Hypothetical Energy Conmentioning

confidence: 99%

Why Flavins Are not Competitors of Chlorophyll in the Evolution of Biological Converters of Solar Energy

Kritsky

Телегина

Vechtomova

et al. 2012

IJMS

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Excited flavin molecules can photocatalyze reactions, leading to the accumulation of free energy in the products, and the data accumulated through biochemical experiments and by modeling prebiological processes suggest that flavins were available in the earliest stages of evolution. Furthermore, model experiments have shown that abiogenic flavin conjugated with a polyamino acid matrix, a pigment that photocatalyzes the phosphorylation of ADP to form ATP, could have been present in the prebiotic environment. Indeed, excited flavin molecules play key roles in many photoenzymes and regulatory photoreceptors, and the substantial structural differences between photoreceptor families indicate that evolution has repeatedly used flavins as chromophores for photoreceptor proteins. Some of these photoreceptors are equipped with a light-harvesting antenna, which transfers excitation energy to chemically reactive flavins in the reaction center. The sum of the available data suggests that evolution could have led to the formation of a flavin-based biological converter to convert light energy into energy in the form of ATP.

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Bluelight-induced, flavin-mediated transport of redox equivalents across artificial bilayer membranes

Cited by 19 publications

References 57 publications

BLUE LIGHT INDUCED, REVERSIBLE IN ACTIVATION OF THE TONOPLAST‐TYPE H+‐ATPase FROM CORN COLEOPTILES IN THE PRESENCE OF FLAVINS

BLUE LIGHT INDUCED, REVERSIBLE IN ACTIVATION OF THE TONOPLAST‐TYPE H+‐ATPase FROM CORN COLEOPTILES IN THE PRESENCE OF FLAVINS

ELECTRON AND PROTON PHOTOTRANSPORTS IN A BILAYER MEMBRANE. ACIDIC PORPHYRIN AND SUPEROXIDE ION AS ΔpH SENSITIVE CHARGE CARRIERS

Why Flavins Are not Competitors of Chlorophyll in the Evolution of Biological Converters of Solar Energy

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