Trypsin inhibitor from Poecilanthe parviflora seeds: purification, characterization, and activity against pest proteases.
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.
Centro de Ciências Biológicas e da Saúde, Universidade Federal de Mato Grosso do Sul, CP 549, CEP 79070-900, Campo Grande, MS, Brazil.
Viviane Alves
VA
Garcia
Maria das Graças Machado
Md
Freire
José Camillo
JC
Novello
Sérgio
S
Marangoni
Maria Lígia Rodrigues
ML
Macedo
D000818:Animals; D002853:Chromatography, Liquid; D007887:Fabaceae / Q000737:chemistry*; D041981:Gastrointestinal Tract / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D007300:Insect Control; D008970:Molecular Weight; D009036:Moths / Q000187:drug effects / Q000201:enzymology*; D010447:Peptide Hydrolases / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry*; D013696:Temperature; D014361:Trypsin Inhibitors / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology
D014361:Trypsin Inhibitors; D010447:Peptide Hydrolases