Purification of a Kunitz-type inhibitor from Acacia polyphyllaDC seeds: characterization and insecticidal properties against Anagasta kuehniella Zeller (Lepidoptera: Pyralidae)

• Published in: Journal of agricultural and food chemistry Vol. 61; no. 10; pp. 2469 - 2478
• Main Authors: Machado, Suzy Wider, de Oliveira, Caio Fernando Ramalho, Bezerra, Cezar da Silva, Freire, Maria das Graças Machado, Regina Kill, Marta, Machado, Olga Lima Tavares, Marangoni, Sergio, Macedo, Maria Ligia Rodrigues
• Format: Journal Article
• Language: English
• Published: United States 13-03-2013
• Subjects: Acacia - chemistry; Amino Acid Sequence; Animals; Digestion - drug effects; Insecticides - chemistry; Insecticides - isolation & purification; Insecticides - pharmacology; Larva - drug effects; Larva - growth & development; Larva - physiology; Molecular Sequence Data; Moths - drug effects; Moths - growth & development; Moths - physiology; Peptides - chemistry; Peptides - isolation & purification; Peptides - pharmacology; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - isolation & purification; Plant Proteins - pharmacology; Seeds - chemistry; Sequence Alignment; Serine Proteinase Inhibitors - chemistry; Serine Proteinase Inhibitors - genetics; Serine Proteinase Inhibitors - isolation & purification; Serine Proteinase Inhibitors - pharmacology
• ISSN: 1520-5118
• DOI: 10.1021/jf3049565

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.