Trypsin inhibitor from Poecilanthe parviflora seeds: purification, characterization, and activity against pest proteases

• Published in: The Protein Journal Vol. 23; no. 5; pp. 343 - 350
• Main Authors: Garcia, Viviane Alves, Freire, Maria das Graças Machado, Novello, José Camillo, Marangoni, Sérgio, Macedo, Maria Lígia Rodrigues
• Format: Journal Article
• Language: English
• Published: Netherlands Springer Nature B.V 01.07.2004
• Subjects: Animals; Chromatography, Liquid; Fabaceae - chemistry; Gastrointestinal Tract - enzymology; Hydrogen-Ion Concentration; Insect Control; Liquid chromatography; Molecular Weight; Moths - drug effects; Moths - enzymology; Peptide Hydrolases - chemistry; Proteinase inhibitors; Seeds; Seeds - chemistry; Temperature; Trypsin Inhibitors - chemistry; Trypsin Inhibitors - isolation & purification; Trypsin Inhibitors - pharmacology
• DOI: 10.1023/B:JOPC.0000032654.67733.d5
• ISSN: 1572-3887

Plants synthesize a variety of molecules, including proteinaceous proteinase inhibitors, to defend themselves of being attacked by insects. In this work, a novel trypsin inhibitor (PPTI) was purified from the seeds of the native Brazilian tree Poecilanthe parviflora (Benth) (Papilioinodeae, Leguminosae) by gel filtration chromatography on a Sephadex G-100 followed by Superdex G75 chromatography (FPLC), Sepharose 4B-Trypsin column, and fractionated by reversed-phase HPLC on a C-18 column. SDS-PAGE showed that PPTI consisted of a single polypeptide chain with molecular mass of about 16 kDa. The dissociation constant of 1.0 x 10(-7) M was obtained with bovine trypsin. PPTI was stable over a wide range of temperature and pH and in the presence of DTT. The N-terminal sequence of the PPTI showed a high degree of homology with other Kunitz-type inhibitors. Trypsin-like activity in midguts of larval Diatraea saccharalis, Anagasta kuehniella, Spodoptera frugiperda, and Corcyra cephalonica were substantially inhibited by PPTI.