In vitro reconstitution of light-harvesting POR-protochlorophyllide complex with protochlorophyllides a and b
| Autor: | Frank Buhr, Stephan Pollmann, Steffen Reinbothe, Christiane Reinbothe |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2003 |
| Předmět: |
0106 biological sciences
Oxidoreductases Acting on CH-CH Group Donors Light Biología Blotting Western Biology 01 natural sciences Biochemistry 03 medical and health sciences Pigment Greening Protochlorophyllide Oxidoreductase Molecular Biology Chromatography High Pressure Liquid 030304 developmental biology Plant Proteins chemistry.chemical_classification 0303 health sciences Hordeum Cell Biology Fluorescence In vitro Enzyme chemistry visual_art visual_art.visual_art_medium Etioplasts Oxidoreductases 010606 plant biology & botany |
| Zdroj: | Journal of Biological Chemistry, ISSN 0021-9258, 2003, Vol. 278, No. null Archivo Digital UPM Universidad Politécnica de Madrid |
| Popis: | NADPH:protochlorophyllide oxidoreductase (POR; EC1.1.33.1) is a key enzyme for the light-induced greening of angiosperms. In barley, two POR proteins exist, termed PORA and PORB. These have previously been proposed to form higher molecular weight light-harvesting complexes in the prolamellar body of etioplasts (Reinbothe, C., Lebedev, N., and Reinbothe, S. (1999)Nature 397, 80–84). Here we report the in vitro reconstitution of such complexes from chemically synthesized protochlorophyllides (Pchlides) a andb and galacto- and sulfolipids. Low temperature (77 K) fluorescence measurements revealed that the reconstituted, lipid-containing complex displayed the same characteristics of photoactive Pchlide 650/657 as the presumed native complex in the prolamellar body. Moreover, Pchlide F650/657 was converted to chlorophyllide (Chlide) 684/690 upon illumination of the reconstituted complex with a 1-ms flash of white light. Identification and quantification of acetone-extractable pigments revealed that only the PORB-bound Pchlide a had been photoactive and was converted to Chlide a, whereas Pchlide b bound to the PORA remained photoinactive. Nondenaturing PAGE of the reconstituted Pchlide a/b-containing complex further demonstrated a size similar to that of the presumed native complexin vivo, suggesting that both complexes may be identical. |
| Databáze: | OpenAIRE |
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