Formation of truncated proteins and high-molecular-mass aggregates upon soft illumination of photosynthetic proteins.
Different spot profiles were observed in 2D gel electrophoresis of thylakoid membranes performed either under complete darkness or by leaving the sample for a short time to low visible light. In the latter case, a large number of new spots with lower molecular masses, ranging between 15,000 and 25,000 Da, were observed, and high-molecular-mass aggregates, seen as a smearing in the upper part of the gel, appeared in the region around 250 kDa. Identification of protein(s) contained in these new spots by MS/MS revealed that most of them are simply truncated proteins deriving from native ones, fragments, or aggregates. This resulted from the formation of extremely reactive oxygen species (ROS) that can derive by the exposure of chlorophyll binding proteins of photosynthetic apparatus to low-intensity light during laboratory manipulation of sample for electrophoresis runs.
Rinalducci
Sara
S
Department of Environmental Sciences, Tuscia University, Viterbo, Italy.
Campostrini
Natascia
N
Antonioli
Paolo
P
Righetti
Pier Giorgio
PG
Roepstorff
Peter
P
Zolla
Lello
L
D002851:Chromatography, High Pressure Liquid; D004586:Electrophoresis; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods*; D007737:Kynurenine / Q000031:analogs & derivatives / Q000737:chemistry; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry; D008280:Magnetics; D013058:Mass Spectrometry; D008956:Models, Chemical; D010449:Peptide Mapping; D010455:Peptides / Q000737:chemistry; D010775:Photic Stimulation; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D020543:Proteome; D040901:Proteomics / Q000379:methods*; D017382:Reactive Oxygen Species; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D020524:Thylakoids / Q000378:metabolism; D013997:Time Factors
D045342:Light-Harvesting Protein Complexes; D010455:Peptides; D045322:Photosynthetic Reaction Center Complex Proteins; D011506:Proteins; D020543:Proteome; D017382:Reactive Oxygen Species; C007772:N'-formylkynurenine; D007737:Kynurenine