title: Identification of non-zein proteins in BR473 maize protein bodies by LC-nanoESI-MS/MS.
abstract: The nutritional value of maize seed is limited due to its high content of storage proteins (zeins), which are deficient in essential amino acids such as lysine and tryptophan. In a previous paper, we showed that protein bodies obtained from BR473 maize variety, developed by Embrapa (Brazilian Agricultural Research Corporation), were mainly constituted by Z27 and a smaller quantity of Z50 gamma-zeins. Besides zein proteins, other not identified protein band in the SDS/PAGE was also observed, which could indicate the presence of non-zein proteins additionally to gamma-zeins. In the present paper, we have demonstrated the presence of non-zein proteins in BR473 maize protein bodies by LC-nanoESI-MS/MS and database searching. This fact could be related to the excellent energetic value and higher protein quality of BR473 maize grains, since high lysine concentration in some maize varieties has been related to the presence of cytoskeleton proteins that are non-zeins. We have identified the following proteins: Brittle-1 protein (chloroplast precursor), Legumin-1, glyceroldehyde-3-phosphate dehydrogenase, and elongation factor 1-alpha.
authors.affiliation: Instituto de Química de São Carlos, Laboratório de Cromatografia, Universidade de São Paulo, São Carlos/SP, Brazil.
authors.forename: Rogério Campos
authors.initials: RC
authors.lastname: Bicudo
authors.forename: Tatiana Campos
authors.initials: TC
authors.lastname: Bicudo
authors.forename: Lucimara A
authors.initials: LA
authors.lastname: Forato
authors.forename: Guilherme M
authors.initials: GM
authors.lastname: Titato
authors.forename: Luiz A
authors.initials: LA
authors.lastname: Colnago
authors.forename: Fernando M
authors.initials: FM
authors.lastname: Lanças
mesh_terms: D000595:Amino Acid Sequence; D002853:Chromatography, Liquid / Q000379:methods*; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D003313:Zea mays / Q000737:chemistry*; D015028:Zein / Q000737:chemistry*
chemical_list: D010940:Plant Proteins; D015028:Zein