Purification and characterization of a Kunitz inhibitor from Poincianella pyramidalis with insecticide activity against the Mediterranean flour moth.
This paper describes the characterization of a trypsin inhibitor from Poincianella pyramidalis seeds (PpyTI). The partial sequencing of PpyTI revealed homology to Kunitz inhibitors, clustered as a member of Family I03 in MEROPS database. PpyTI has a single polypeptide chain of 19,042 Da and presents stability at high temperatures (up to 70 °C) and a wide range of pH. In vitro assays showed that disulfide bridges have an important stabilization role of reactive site in PpyTI, a characteristic shared among several Kunitz inhibitors. Bioassays carried out with the Mediterranean flour moth (Anagasta kuehniella) revealed a significant decrease in both larval weight and survival of PpyTI-fed larvae, besides a larval stage extension. Through biochemical analysis, we demonstrated that the PpyTI insecticide effects were triggered by digestion process commitment, through the inhibition of trypsin and chymotrypsin activities, the major digestive enzymes in this species. The insecticide effects and biochemical characterization of PpyTI encourage further studies using this inhibitor for insect pest control.
Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, SP 13083-970, Brazil; Department of Food Technology and Public Health, Center for Biological and Health Sciences, University of Mato Grosso do Sul, Campo Grande, MS 79070-900, Brazil.
Lays Cordeiro
LC
Guimarães
Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, SP 13083-970, Brazil; Department of Food Technology and Public Health, Center for Biological and Health Sciences, University of Mato Grosso do Sul, Campo Grande, MS 79070-900, Brazil.
Caio Fernando Ramalho
CF
de Oliveira
Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, SP 13083-970, Brazil.
Sergio
S
Marangoni
Department of Food Technology and Public Health, Center for Biological and Health Sciences, University of Mato Grosso do Sul, Campo Grande, MS 79070-900, Brazil.
Daniella Gorete Lourenço
DG
de Oliveira
Department of Food Technology and Public Health, Center for Biological and Health Sciences, University of Mato Grosso do Sul, Campo Grande, MS 79070-900, Brazil. Electronic address: bioplant@terra.com.br.
Maria Lígia Rodrigues
ML
Macedo
D000595:Amino Acid Sequence; D000818:Animals; D004063:Digestion; D007887:Fabaceae / Q000737:chemistry*; D041981:Gastrointestinal Tract / Q000187:drug effects / Q000201:enzymology / Q000502:physiology; D019476:Insect Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D007306:Insecticides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009036:Moths / Q000187:drug effects* / Q000201:enzymology; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D016415:Sequence Alignment; D014361:Trypsin Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
D019476:Insect Proteins; D007306:Insecticides; D010936:Plant Extracts; D014361:Trypsin Inhibitors
Anagasta kuehniella; Kunitz inhibitors; Pest control; Poincianella pyramidalis