GENETIC-VARIABILITY IN THE STRUCTURE OF THE ALPHA-SUBUNITS OF LEGUMIN FROM PISUM - TWO-DIMENSIONAL GEL-ELECTROPHORESIS STUDY

Variant forms of legumin (one of the major storage globulins of Pisum seeds) were purified by immunoaffinity chromatography from a range of Pisum types, includingP.fulvum, and primitiveforms, modern cultivarsand advanced breeding selections of P. sativum. The purified variants, all of which had sedimentation coefficients of about 12S and leucine, threonine and glycine as N-terminal amino acids, showed subunit heterogeneity on polyacrylamide gels containing sodium dodecyl sulphate and on two-dimensional isofocusing/electrophoresis. Comparison of legumins from different Pisum types showed variability, both in the net surface charge of the whole molecule and in the nature of subunit heterogeneity on two-dimensional gels. The usefulness of two-dimensional gels in the genetic analysis of pea seed storage protein structure was stressed and the role of potential artefacts in such analyses assessed. © 1979 The Genetical Society of Great Britain.