Isolation and partial sequence of a Kunitz-type elastase specific inhibitor from marama bean (Tylosema esculentum)

Deepa Nadaraja, Susan T. Weintraub, Kevin W. Hakala, Nicholas E. Sherman, Barry Starcher

Research output: Contribution to journalArticle

7 Scopus citations


An isolation procedure utilizing ammonium sulfate fractionation and affinity chromatography was used to purify an elastase inhibitor present in large amounts in marama beans (Tylosema esculentum). The protein appeared to be heterogeneous due to carbohydrate differences, demonstrating two bands on SDS gels with molecular weights of 17.8kDa and 20kDa. Partial sequence, derived from mass spectrometry, indicated that the protein is a Kunitz-type inhibitor distinct from other known plant serine protease inhibitors. The marama bean inhibitor is specific for elastase, with very low Ki for both pancreatic and neutrophil elastase. The quantity of elastase inhibitor present in marama beans is many times greater than in soybean or any other bean or nut source reported to date. This raises the question of why a bean found in an arid corner of the Kalahari Desert would be so rich in a very potent elastase inhibitor.

Original languageEnglish (US)
Pages (from-to)377-382
Number of pages6
JournalJournal of Enzyme Inhibition and Medicinal Chemistry
Issue number3
StatePublished - Apr 30 2010



  • Amino acid sequence
  • Elastase inhibitor
  • Marama bean

ASJC Scopus subject areas

  • Pharmacology
  • Drug Discovery

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