Phycocyanobilin synthesis in the unicellular rhodophyte Cyanidium caldarium
| Autor: | R F Troxler, P Kelly, S B Brown |
|---|---|
| Rok vydání: | 1978 |
| Předmět: |
macromolecular substances
Cyanidium caldarium Biology Biochemistry Mass Spectrometry chemistry.chemical_compound Pigment Phycocyanobilin Phycobilins Phycocyanin Pyrroles Phycobilin Bile Pigments Imide Molecular Biology Pigments Biological Cell Biology Chromophore chemistry Covalent bond visual_art Rhodophyta visual_art.visual_art_medium Chromatography Thin Layer Research Article |
| Zdroj: | Biochemical Journal. 172:569-576 |
| ISSN: | 0264-6021 |
| DOI: | 10.1042/bj1720569 |
| Popis: | Light is required for synthesis of the accessory photosynethetic pigment phycocyanin in cells of the unicellular rhodophyte Cyanidium caldarium. Phycocyanin is a conjugated protein composed of polypeptide subunits to which the light-absorbing bile pigment chromophore phycocyanobilin is covalently attached. Dark-grown cells of C. caldarium are unable to make phycocyanin, but when incubated in the dark with 5-aminolaevulinate the cells synthesize and excrete a protein-free phycobilin (algal bile pigment) into the suspending medium. The electronic absorption spectrum, electron impact mass spectrum, chromatographic properties and imide products obtained after chronic acid degradation of the excreted phycobilin were identical with those of phycocyanobilin cleaved from phycocyanin in boiling methanol. This establishes the structural identity between the excreted phycobilin, which is the end product of bile-pigment synthesis in vivo, and the chromophore cleaved from phycocyanin in boiling methanol. The significance of the structure of the excreted phycobilin with respect to the events surrounding the assembly of the phycocyanin molecule in vivo is discussed. |
| Databáze: | OpenAIRE |
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