Purification and properties of an endospermic protein of maize associated with the Opaque-2 and Opaque-6 genes.
Maize endosperms accumulate during development a large amount of storage proteins (zeins). The rate of zein accumulation is under the control of several regulatory genes. Two of these, the opaque-2 and opaque-6 mutants, lower the zein level, thus improving the nutritional quality of maize meals. An endosperm protein of Mr 32 000 (b-32) appears to be correlated with the zein level. The b-32 protein is encoded by the opaque-6 gene which, in turn, is activated by opaque-2. We report the purification, amino-acid composition and peptide map of b-32 protein. Furthermore we demonstrate that the protein exists as a monomer likely located in the soluble cytoplasm. As a step towards the isolation of a complementary-DNA clone for b-32 protein, the purification of its corresponding mRNA is described.
Sezione Maiscoltura, Istituto Sperimentale per la Cerealicoltura, Bergamo, Italy.
N
N
Di Fonzo
L
L
Manzocchi
F
F
Salamini
C
C
Soave