Protein-bound selenium in the seeds of coco de mono (Lecythis ollaria).
High selenium concentrations (7-12 g/kg dry mass) were found in the seeds of the selenium-accumulator plant coco de mono (Lecythis ollaria). In order to obtain information on the protein-bound part of selenium in extracts of these seeds, dialysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used combined with neutron activation analysis. Extractions were carried out at pH 4.5 and 7.5. In both cases about 90% of the element was dissolved. Of the extracted selenium only 9% was shown to be firmly bound to proteins at pH 4.5 and 29% at pH 7.5. For the protein-bound selenium, concentrations of 0.7 g and 2.4 g per kg of seeds and 40 and 25 g per kg of extractable protein were determined at pH 4.5 and 7.5, respectively. By analyzing the protein fractions separated by SDS-PAGE the element was found to be present in extremely selenium-rich proteins with molecular masses below 20 kDa.
Hammel
C
C
Hahn-Meitner-Institut Berlin, Department Trace Elements in Health and Nutrition, Germany.
Kyriakopoulos
A
A
Behne
D
D
Gawlik
D
D
Brätter
P
P
D005591:Chemical Fractionation; D003956:Dialysis; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry*; D010945:Plants, Edible / Q000737:chemistry*; D011485:Protein Binding; D012639:Seeds; D012643:Selenium / Q000032:analysis*; D014462:Ultrafiltration
D010940:Plant Proteins; D012643:Selenium