gamma-Purothionins: amino acid sequence of two polypeptides of a new family of thionins from wheat endosperm

FEBS Lett. 1990 Sep 17;270(1-2):191-4. doi: 10.1016/0014-5793(90)81265-p.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amino Acids / analysis
  • Antimicrobial Cationic Peptides
  • Molecular Sequence Data
  • Plant Proteins / chemistry*
  • Plant Proteins / isolation & purification
  • Seeds / analysis
  • Sequence Homology, Nucleic Acid
  • Triticum / analysis*

Substances

  • Amino Acids
  • Antimicrobial Cationic Peptides
  • Plant Proteins
  • gamma1-purothionin, Triticum aestivum
  • gamma2-purothionin protein, Triticum aestivum
  • purothionin