Electrophoretic analysis of sucrose synthetase proteins in the complementing heterozygotes at the Shrunken locus in maize.

Electrophoretic comparisons of sucrose synthetase (SS) proteins in complementing heterozygotes and the corresponding in vitro mixtures of extracts from the homozygotes are described. The latter revealed two protein bands in the expected fashion. The SS protein pattern in the hybrid was different from that of the mixtures. The possibility of heteromeric SS molecules, formed by random polymerization of subunits of the tetramer coded by each allele in the heterozygote, was considered. Such an interaction was expected to form a multiple of five SS proteins that could be visualized after gel electrophoresis. However, only two SS bands were seen in the hybrids. The basis of this marked deviation remains to be explained.