Separation and identification of the light harvesting proteins contained in grana and stroma thylakoid membrane fractions.

摘要: Abstract This paper presents the results of a study performed to develop rapid and straightforward method resolve simultaneously identify light-harvesting proteins photosystem I (LHCI) II (LHCII) present in grana stroma thylakoid membranes higher plants. These hydrophobic are embedded phospholipid membrane, their extraction usually requires detergent time consuming manipulations that may introduce artifacts. The presented here makes use digitonin, which causes (within less than 3 min) cleavage membrane into two subfractions: appressed (grana) non-appressed (stroma) membranes, former enriched latter containing mainly I. From these fractions identification protein components was by separating them reversed-phase high-performance liquid chromatography (RP-HPLC) determining intact molecular mass electrospray ionization spectrometry (ESI-MS). By this strategy ion suppression during ESI-MS normally occurs presence phospholipids avoided, since RP-HPLC removed most from analytes. Consequently, high quality spectra were extracted reconstructed chromatograms. specific as well quantification antenna composition complexes facilitate future studies lateral migration chlorophyll-protein along is known be induced intensity light or other environmental stresses. Such investigations could not sodium dodecylsulfate–polyacrylamide gel electrophoresis because insufficient resolution having masses between 22 000 25 000.