title: Purification of a Kunitz-type inhibitor from Acacia polyphyllaDC seeds: characterization and insecticidal properties against Anagasta kuehniella Zeller (Lepidoptera: Pyralidae).
abstract: Anagasta kuehniella is a polyphagous pest that causes economic losses worldwide. This species produces serine proteases as its major enzymes for protein digestion. In this study, a new serine-protease inhibitor was isolated from Acacia polyphylla seeds (AcKI).Further analysis revealed that AcKI is formed by two polypeptide chains with a relative molecular mass of ∼20 kDa. The effects of AcKI on the development, survival, and enzymatic activity of Anagasta kuehniella larvae were evaluated, by incorporating AcKI in an artificial diet. Bioassays revealed a reduction in larval weight of ∼50% with the lower concentration of AcKI used in the study (0.5%). Although additionalassays showed an increase in endogenous trypsin and chymotrypsin activities, with a degree of AcKI-insensivity, AcKI produces an anti nutritional effect on A. kuehniella, indicating AcKI as a promising bioinsecticide protein for engineering plants that are resistant to insect pests.
authors: Laboratório de Purificação de Proteínas e suas Funções Biológicas, Centro de Ciências Biológicas e Saúde, Universidade Federal do Mato Grosso do Sul , Campo Grande 79070-900, MS, Brazil.
authors: Suzy Wider
authors: SW
authors: Machado
authors: Caio Fernando Ramalho
authors: CF
authors: de Oliveira
authors: Cezar da Silva
authors: Cda S
authors: Bezerra
authors: Maria das Graças Machado
authors: Md
authors: Freire
authors: Marta
authors: M
authors: Regina Kill
authors: Olga Lima Tavares
authors: OL
authors: Machado
authors: Sergio
authors: S
authors: Marangoni
authors: Maria Ligia Rodrigues
authors: ML
authors: Macedo
mesh_terms: D000045:Acacia / Q000737:chemistry*; D000595:Amino Acid Sequence; D000818:Animals; D004063:Digestion / Q000187:drug effects; D007306:Insecticides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D007814:Larva / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D008969:Molecular Sequence Data; D009036:Moths / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology; D012639:Seeds / Q000737:chemistry*; D016415:Sequence Alignment; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D007306:Insecticides; C053865:Kunitz-type protease inhibitor, plant; D010455:Peptides; D010940:Plant Proteins; D015842:Serine Proteinase Inhibitors