01839naa a2200205 a 450000100080000000500110000800800410001910000190006024501450007926000090022452012140023365000090144765000190145665000350147565000100151070000170152070000140153770000190155177300630157014891442018-05-29       1990    bl uuuu     u00u1 u    #d1 aWALLACE, J. C.  aNew methods for extraction and quantitation of zeins reveal a high content of gamma -zein in modified opaque-2 maize.h[electronic resource]  c1990  aWe have developed methods for quantitative extraction and analysis of zeins from maize (Zea mays L.) flour. Extraction involved solubilization of total endosperm proteins in an alkaline buffer containing SOS and 2-mercaptoethanol with subsequent precipitation of nonzein proteins by the addition of ethanol to 70%. Analysis of these proteins by SOS-PAGE with Coomassie bluestaining and by Western bloHing and ELlSA assay with zein antibodies revealed that this extraction method is more quantitative than the traditional Landry-Moureaux procedure, especially for the (J-and')'-zeins. This method was used to extract and analyze the zein content of several 'Quality Protein Maize' (QPM) varieties developed by the International Maize and Wheat Improvement Center. QPM varieties contain 'modifiergenes' that confer a vitreous phenotype on opaque·2 genotypes, while maintaining the elevated levels of Iysine and tryptophan characteristic of this mutant. This analysis revealed that the QPM types contain 2 to 4 times the amount of the ')'-zein than unmodified opaque-2 or normal maize varieties. Possible relationships between the high expression of the ')'-zein and the modified opaque phenotype are discussed.  aCorn  aPlant breeding  aMelhoramento genético vegetal  aMilho1 aLOPES, M. A.1 aPAIVA, E.1 aLARKINS, B. A.  tPlant Physiology, Bethesdagv. 92, n. 1, p. 191-196, 1990.