SPECIFICITY OF ANTISERA RAISED AGAINST SYNTHETIC PEPTIDE-FRAGMENTS OFHIGH M(R) GLUTENIN SUBUNITS

In an attempt to detect high M(r) glutenin subunits specifically by im munochemical means, antisera were produced against synthetic peptides corresponding to three N-terminal sequences and to two repetitive moti fs of high M(r) glutenin subunits. The three N-terminal peptides, NT1, NT2 and NT3, differed by a single substitution at the sixth position and correspond, respectively, to the N-termini off Dx subunits, Ax and Ex subunits and By and Dy subunits. The anti-peptide sera did not cro ss react with gliadins or with low M(r) glutenin subunits, and differe d in their ability to recognise high M(r) glutenin subunits. The antis era to the repetitive motifs recognised all high M(r) glutenin subunit s, whereas the antisera to the N-terminal peptides detected only some of the subunits. The antiserum directed against the N-terminal peptide from Dx subunits detected these subunits specifically, whereas the an tiserum directed against the N-terminal peptide corresponding to y typ e subunits did not react with the homologous subunits although it did react with Dx or Ex subunits. Antisera were also produced against inte rnal sequences present in the N-terminal domain specific for x and for y-type subunits, but these antisera did not react with the cognate pr oteins. The failure of some anti-peptide sera to recognise the homolog ous high M(r) glutenin subunits may be due to differences in conformat ion between peptides and the corresponding regions in proteins. (C) 19 96 Academic Press Limited