Characterization of pea vicilin. 1. Denoting convicilin as the alpha-subunit of the Pisum vicilin family.
Vicilin, a major globulin protein of pea that has been described as "extremely heterogeneous in terms of its polypeptide composition", was extracted from pea flour under alkaline conditions and subsequently fractionated by salt under acid conditions. This procedure induced the separation of vicilin into two fractions, which, after purification, were called vicilin 1 degrees and vicilin 2 degrees. Vicilin 2 degrees was seen on SDS-PAGE to contain the third globulin protein of pea, convicilin (a band at approximately 70 kDa). Vicilin fractions were thus characterized using gel electrophoresis, differential scanning calorimetry, circular dichroism, and pH-dependent solubility in order to determine whether the convicilin should in fact be considered as a third separate globulin protein of pea. On the basis of the results obtained it was concluded that this distinct polypeptide of the Pisum vicilin gene family should be further denoted as a subunit of the salt extractable protein vicilin. The definition of vicilin heterogeneity should therefore be extended to acknowledge the possible oligomeric inclusion of the 70 kDa polypeptide that is here denoted as the alpha-subunit.
O'Kane
Francesca E
FE
Product Design and Quality Management Group, Centre for Protein Technology TNO-WU, and Laboratory of Food Chemistry, Wageningen University, Wageningen, The Netherlands.
Happe
Randolph P
RP
Vereijken
Johan M
JM
Gruppen
Harry
H
van Boekel
Martinus A J S
MA
D002152:Calorimetry, Differential Scanning; D005591:Chemical Fractionation; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D018532:Pisum sativum / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D017433:Protein Structure, Secondary; D055314:Seed Storage Proteins; D012995:Solubility
C029781:CVC protein, Pisum sativum; D010940:Plant Proteins; D055314:Seed Storage Proteins; C015575:vicilin protein, plant