gamma-Purothionins: amino acid sequence of two polypeptides of a new family of thionins from wheat endosperm.
Two homologous sulfur-rich basic polypeptides form wheat endosperm, so-called gamma 1-purothionin and gamma 2-purothionin, are described. Purification involves extraction with volatile solvents and ammonium bicarbonate fractionation followed by reversed-phase high-performance liquid chromatography. The complete primary structure of these two polypeptides has been determined by automatic degradation of the intact, S-carboxymethylated gamma-purothionins and peptides obtained by enzymatic cleavage. gamma 1-Purothionin and gamma 2-purothionnin consist of 47 amino acids with an molecular weight of 5239 and 5151 Da, respectively and 8 cysteines organized in 4 disulfide bridges. They present a high degree of homology among themselves (89% of identity) and are the first two thionin-like polypeptides, so-called gamma-thionins, described from wheat endosperm.
Colilla
F J
FJ
Servicio de Endocrinologia, Hospital Ramon y Cajal, Madrid, Spain.
Rocher
A
A
Mendez
E
E
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D023181:Antimicrobial Cationic Peptides; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D012639:Seeds / Q000032:analysis; D012689:Sequence Homology, Nucleic Acid; D014908:Triticum / Q000032:analysis*
D000596:Amino Acids; D023181:Antimicrobial Cationic Peptides; D010940:Plant Proteins; C066241:gamma1-purothionin, Triticum aestivum; C066242:gamma2-purothionin protein, Triticum aestivum; C016085:purothionin