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Purification and characterisation of seed globulins from black gram ( Phaseolus mungo )
Author(s) -
Chavan Jayasing K.,
Djurtoft Robert
Publication year - 1982
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740330513
Subject(s) - globulin , immunoelectrophoresis , size exclusion chromatography , biochemistry , vicilin , legumin , biology , polyacrylamide gel electrophoresis , phaseolus , isoelectric focusing , gel electrophoresis , chromatography , storage protein , chemistry , antibody , botany , immunology , gene , enzyme
The salt‐soluble proteins and crude globulins of black gram ( Phaseolus mungo , Rox b), using crossed immunoelectrophoresis for identification, were separated into 28–29 and seven to eight individual components, respectively. Three major globulins (G1, G2 and G3), of which G1 was identified as a glycoprotein, were purified by anionexchange chromatography followed by gel filtration. Fused rocket immunoelectrophoresis was used for the localisation of these proteins in the different fractions. In crossed immunoelectrophoresis, purified G1 and G2 globulins each showed a single peak, while G3 globulin still contained four to five distinct peaks. Sodium dodecyl sulphate‐polyacrylamide gel electrophoresis showed three subunits for G1 globulin (molecular weight 64 500, 55 000 and 50 000), three distinct subunits for G2 globulin (mol. wt. 67 000, 60 000 and 16 000), and six distinct subunits for G3 globulin (mol. wt 50 000, 42 000, 28 000, 26 000, 21 000 and 10 000). Isoelectric focusing in 6m urea showed three acidic subunits for G1 globulin. G2 subunits were separated into three acidic and two basic subunits. G3 globulin contained about ten acidic subunits. Immunochemical examination of pure G1 globulin indicated microheterogeneity similar to that found for vicilin extracted from other legume seeds. Based on molecular weights, subunit structure and amino acid composition, the G1 globulin of black gram was found to correspond with vicilin (glycoprotein II), and G2 globulin to legumin of other legume seed proteins. G1 and G3 globulins were found to be major storage proteins in black gram.