Distribution of cadmium-binding components in flax (Linum usitatissimum L.) seed.
The distribution of cadmium- (Cd-) binding components in flaxseed (cultivar NorMan) containing 0.526 ppm (ng/mg) Cd was investigated. Proteins extracted from dehulled, defatted flaxseed were fractionated by anion-exchange and size-exclusion chromatography. The contents of Cd and other metals, UV/visible spectral characteristics, and amino acid compositions of these fractions were analyzed. Over 66% of the eluted Cd was recovered by 0.1 M NaCl elution from DEAE-Sephacel, in a thiol-rich fraction representing only 7% of the extracted proteins. Sephadex G50 size-exclusion chromatography of this 0.1 M NaCl fraction concentrated most of the Cd in a low-molecular-weight peak eluting at V(t). About 72% of the extracted flaxseed proteins eluted from DEAE-Sephacel at 0.25 M NaCl and contained only 25% of the eluted Cd. Because the major Cd-binding fraction is a minor constituent of flaxseed, these results indicate the potential to isolate flaxseed's major storage protein with a low Cd content.
Lei
Bo
B
Faculty of Agricultural Sciences, Food, Nutrition and Health Program, The University of British Columbia, 6650 NW Marine Drive, Vancouver BC V6T 1Z4, Canada.
Li-Chan
Eunice C Y
EC
Oomah
B Dave
BD
Mazza
Giuseppe
G
D000596:Amino Acids / Q000032:analysis; D002104:Cadmium / Q000378:metabolism*; D002352:Carrier Proteins / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004220:Disulfides / Q000032:analysis; D019597:Flax / Q000737:chemistry*; D008970:Molecular Weight; D012639:Seeds / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013438:Sulfhydryl Compounds / Q000032:analysis
D000596:Amino Acids; D002352:Carrier Proteins; D004220:Disulfides; D013438:Sulfhydryl Compounds; D002104:Cadmium