Purification of a Kunitz-type Inhibitor from Acacia polyphylla DC 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, Machado Freire, Maria das Graças, Regina Kill, Marta, Machado, Olga Lima Tavares, Marangoni, Sergio, Macedo, Maria Ligia Rodrigues
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 13.03.2013
• Subjects: Biological and medical sciences; Food industries; Fundamental and applied biological sciences. Psychology; Kunitz-type inhibitor; pest insect; Acacia polyphylla; Anagasta kuehniella; Seeds; Kunitz inhibitor; Insecticide; Purification; Insecta; Pesticides; Properties; Characterization; Pest; Arthropoda; Invertebrata
• ISSN: 0021-8561; 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 additional assays 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.