Use of a single method in the extraction of the seed storage globulins from several legume species. Application to analyse structural comparisons within the major classes of globulins

• Published in: International journal of food sciences and nutrition 2000-09, Vol.51 (5), p.341-352
• Main Authors: FREITAS, Regina L, FERREIRA, Ricardo B, TEIXEIRA, Artur R
• Format: Article
• Language: English
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Chemical Fractionation - methods; Chromatography, Ion Exchange; Electrophoresis, Polyacrylamide Gel - methods; Fabaceae - chemistry; Fabaceae - classification; Food science; Fundamental and applied biological sciences. Psychology; General aspects, investigation methods; Globulins - chemistry; Globulins - isolation & purification; Immunoblotting; Legumes; Plant Proteins - chemistry; Plant Proteins - isolation & purification; Plants, Medicinal; Proteins; Seeds
• ISSN: 0963-7486; 1465-3478
• DOI: 10.1080/096374800426939

In this study, a single, improved methodology was used to extract, fractionate and purify the 11S (legumin-type or related to the α-conglutin from Lupinus albus L.), 7S (vicilin-type or related to the β-conglutin from L. albus) and 2S (related to the γ-conglutin from L. albus) families of proteins from eight legume species: L. albus, Glycine max (L.) Merr., Pisum sativum L., Vicia faba L., Cicer arietinum L., Phaseolus vulgaris L., Lens culinaris Med. and Arachis hypogaea L. The sedimentation coefficients obtained varied from 1.9 to 8.1 for the γ-conglutinrelated proteins, from 5.1 to 10.5 for the β-conglutin-related proteins and from 12.0 to 14.9 for the α-conglutin-related globulins. The γ-conglutin-related proteins is the most heterogenous group. Antibodies produced against each type of γ-conglutin polypeptide chain recognize the other polypeptide chain as well as other polypeptides in the corresponding globulins from all species examined. The 7S globulins are typically composed of a large number of polypeptides, covering a wide range of molecular masses (10 to 70 kD). The presence of disulphide bonds is apparently absent and the occurrence of glycopolypeptides is not widespread. Finally, the 11S globulins are characteristically formed by a limited number of polypeptides that may be divided into a lighter group (20-25 kD) and a heavier group (35-50 kD). The presence of disulphide bonds is apparently widespread but the occurrence of glycopolypeptides seems to be relatively rare. Both the 7S family and the 11S globulins studied by immunoblotting exhibit a low level of structural similarity.