Fractionation of sunflower seed proteins

Abstract

Fractionation of sunflower seed salt-soluble proteins, which amount to nearly 80% of the total seed nitrogen, has been performed by a method we proposed in 1970 and which was confirmed by several others. Three varieties of seeds have been investigated: 'Armavirec,' 'Peredovik,' and a pure strain. The occurrence of three groups of proteic fractions was confirmed. Their proportions, which fluctuate with varieties, are roughly: 20% for "light" (low molecular weight) albumins, 5-10% for "heavy albumins," and 70-80% for globulins. The first group was isolated by Sephadex G-50 chromatography from the other two, which were separated by dialysis. A second chromatography of these three groups on Sephadex G-200 has been realized (with preliminarily calibrated columns for molecular weight evaluations). "Light" albumins appear as a rather homogeneous constituent with a molecular weight of 14,000 and an aminoacid composition showing high amounts of methionine, cystine, arginine and glutamine. "Heavy" albumins, which are still mixed with globulin fractions after dialysis, have a molecular weight of 48,000 and a very different aminoacid composition with a high level of lysine. Globulins are composed of at least four different fractions, two of which (M = 12,000 and M = 25,000) are presumably subunits of the other two and have significantly different aminoacid compositions.

An Insight into Powdery Mildew–Infected, Susceptible, Resistant, and Immune Sunflower Genotypes

“…[31] In sunflower, proteomes were analyzed for abiotic stresses like heavy metal stress, [32,33] drought acclimation, [34] cold acclimation, [29] heterosis, [28,35] and seed quality traits. [36][37][38] With regard to biotic stresses, proteomic analysis of sunflower in response to Sclerotinia sclerotiorum fungus infection is reported. [39] Different donors conferring resistance to powdery mildew infection showed varied levels of resistance.…”

Sunflower proteins: overview of their physicochemical, structural and functional properties

“…Owing to these factors, the reported amounts of the different Osborne fractions vary greatly. Globulins have been found to constitute most of the sunflower proteins, ranging from about 40 to 90%, while albumins account for about 10–30% of the total proteins 7, 15, 95–102. Glutelins and, in particular, prolamins are only minor fractions.…”

“…Albumin seed proteins with sedimentation coefficients of approximately 2S have been reported to account for 20–60% of the total proteins in seeds of dicotyledonous plants 104. In sunflower the 2S albumins (SFAs) make up about 10–30% of the total seed proteins,7, 15, 95–102 the amounts of these components varying widely between genotypes 106, 137. SFAs are basic proteins (average isoelectric pH of about 8.8) with molecular weights ranging from 10 to 18 kDa 137–141.…”

S

“…Rahma and Rao (1979) observed that while there are many reports on the processing and technological aspects of sunflower oil and meal, data on characterization of proteins are meager. This was also confirmed by Sabir et al, 1973;Baudet and Mosse, 1977). Rahma and Rao conducted a study to determine the characterization of the proteins of sunflower cultivated in India.…”