| Autor: |
M. Vuillaume, René Buvet, Roger Vallot, X. Bona, R. Calvayrac |
| Rok vydání: |
1982 |
| Předmět: |
|
| Zdroj: |
Bioelectrochemistry and Bioenergetics. 9:103-115 |
| ISSN: |
0302-4598 |
| DOI: |
10.1016/0302-4598(82)80009-3 |
| Popis: |
We have previously shown that the physiology of caterpillars depends on visible light radiations within the range 630–670 nm corresponding to the absorption of pterobilin, a biosynthesized integumentary pigment. Cell free extracts of integuments exhibit dissolved oxygen photoconsumption and an ATP production which increases with the same light. This leads us to the hypothesis that pterobilin could be a photoreceptor. In this paper, we study the electrochemical behavior of the isolated esterified pterobilin and the natural pterobilin forms (free or chromoprotein) present in cell free extracts. Both isolated pterobilin and supernatant react as a reversible redox system, stable with time, at about 210 mV (n.h.e.) and exhibit an anodic peak at about 700 mV (n.h.e.). After several cycles this anodic peak is no longer observed, but it reappears if pterobilin or supernatants are absorbed on a graphite paste electrode in aerated solution. This corresponds to the oxidation of H2O2 in O2. Pterobilin seems to be able to induce or to catalyse the reduction of O2 to H2O2. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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