Isolation, purification, and biochemical characterization of a novel water soluble protein from Inca peanut (Plukenetia volubilis L.)

J Agric Food Chem. 2002 Aug 14;50(17):4906-8. doi: 10.1021/jf020126a.


A water soluble storage albumin from Inca peanut (IPA) accounted for approximately 25% (w/w) of defatted seed flour weight, representing 31% of the total seed protein. IPA is a 3S storage protein composed of two glycosylated polypeptides, with estimated molecular weights (MW) of 32800 and 34800 Da, respectively. IPA has an estimated sugar content of 4.8% +/- 0.92% (n = 6). IPA is a basic protein (pI of approximately 9.4) and contains all of the essential amino acids in adequate amounts when compared to the FAO/WHO recommended pattern for a human adult. The tryptophan content of IPA is unusually high (44 mg/g of protein), whereas the phenylalanine content is low (9 mg/g of protein). IPA is a highly digestible protein in vitro.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amino Acids, Essential / analysis
  • Dimerization
  • Electrophoresis, Polyacrylamide Gel
  • Endopeptidases / metabolism
  • Hot Temperature
  • Molecular Sequence Data
  • Molecular Weight
  • Phenylalanine / analysis
  • Plant Proteins / chemistry*
  • Plant Proteins / isolation & purification*
  • Plant Proteins / metabolism
  • Protein Denaturation
  • Seeds / chemistry*
  • Tryptophan / analysis
  • Water


  • Amino Acids, Essential
  • Plant Proteins
  • Water
  • Phenylalanine
  • Tryptophan
  • Endopeptidases