johnson-isolationandcharacterization-1989.pdf (1.64 MB)
Isolation and characterization of protein bodies in Lupinus angustifolius
journal contribution
posted on 1989-12-01, 00:00 authored by K R Gayler, F Wachsmann, S Kolivas, R Nott, Liz JohnsonLiz JohnsonUsing Nycodenz, a novel density gradient medium, we isolated intact protein bodies from developing seeds of Lupinus angustifolius L. (cultivar Unicrop) and achieved excellent separation from the endoplasmic reticulum, mitochondria, and other organelles. The distribution of the storage protein conglutin-,# was taken as evidence that up to 96% of the protein bodies remained intact on the gradients and banded at 1.25 grams per milliliter. The protein bodies also contained the three other abundant proteins present in L. angustifolius seeds: conglutins-a, -y, and -a. Pulse labeling experiments were carried out to determine the site of proteolytic
processing of conglutin-a, a legumin-like 1 lSvedberg unit storage protein. Cotyledons aged either 33 or 40 days after flowering were pulsed with [3H]leucine. Protein bodies obtained from the cotyledons aged 33 days after flowering contained only the labeled precursors of conglutin-a with molecular weights 85,000, 72,000, and 64,000, even after a 4 hour chase of the radioactivity. Protein bodies obtained from the cotyledons aged 40 days after flowering contained the same radioactive precursors if the tissue had been pulsed for 2 hours, and the processing products of
these precursors when the tissue had been chased for 4 hours. These studies confirm that the subcellular location of proteolytic cleavage of this legumin-like protein is the protein body, that this activity is detected only in protein bodies from lupin seeds aged between 33 and 40 days of seed development after flowering and that protein bodies from seeds younger than this contain only unprocessed conglutin-a.
processing of conglutin-a, a legumin-like 1 lSvedberg unit storage protein. Cotyledons aged either 33 or 40 days after flowering were pulsed with [3H]leucine. Protein bodies obtained from the cotyledons aged 33 days after flowering contained only the labeled precursors of conglutin-a with molecular weights 85,000, 72,000, and 64,000, even after a 4 hour chase of the radioactivity. Protein bodies obtained from the cotyledons aged 40 days after flowering contained the same radioactive precursors if the tissue had been pulsed for 2 hours, and the processing products of
these precursors when the tissue had been chased for 4 hours. These studies confirm that the subcellular location of proteolytic cleavage of this legumin-like protein is the protein body, that this activity is detected only in protein bodies from lupin seeds aged between 33 and 40 days of seed development after flowering and that protein bodies from seeds younger than this contain only unprocessed conglutin-a.
History
Journal
Plant physiologyVolume
91Issue
4Pagination
1425 - 1431Publisher
American Society of Plant Biologists (ASPB)Location
Rockville, Md.Publisher DOI
Link to full text
ISSN
0032-0889eISSN
1532-2548Language
enPublication classification
C1.1 Refereed article in a scholarly journalCopyright notice
1989, American Society of Plant BiologistsUsage metrics
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