title: Negative effects of a nonhost proteinase inhibitor of ~19.8 kDa from Madhuca indica seeds on developmental physiology of Helicoverpa armigera (Hübner).
abstract: An affinity purified trypsin inhibitor from the seed flour extracts of Madhuca indica (MiTI) on denaturing polyacrylamide gel electrophoresis showed that MiTI consisted of a single polypeptide chain with molecular mass of ~19.8 kDa. MiTI inhibited the total proteolytic and trypsin-like activities of the midgut proteinases of Helicoverpa armigera larvae by 87.51% and 76.12%, respectively, at concentration of 5 µg/mL with an IC50 of 1.75 µg/mL against trypsin like midgut proteinases. The enzyme kinetic studies demonstrated that MiTI is a competitive inhibitor with a K i value of 4.1 × 10(-10) M for Helicoverpa trypsin like midgut proteinases. In vivo experiments with different concentrations of MiTI in artificial diet (0.5, 1.0, and 1.5% w/w) showed an effective downfall in the larval body weight and an increase in larval mortality. The concentration of MiTI in the artificial diet to cause 50% mortality (LD50) of larvae was 1.5% w/w and that to cause reduction in mass of larvae by 50% (ED50) was 1.0% w/w. Nutritional indices observations suggest the toxic and adverse effects of MiTI on the growth and development of H. armigera larvae. The results suggest a strong bioinsecticidal potential of affinity purified MiTI which can be exploited in insect pest management of crop plants.
authors.affiliation: Department of Biochemistry, Dr. Ram Manohar Lohia Avadh University, Faizabad 224001, India.
authors.forename: Farrukh
authors.initials: F
authors.lastname: Jamal
authors.affiliation: Department of Biochemistry, Dr. Ram Manohar Lohia Avadh University, Faizabad 224001, India.
authors.forename: Dushyant
authors.initials: D
authors.lastname: Singh
authors.affiliation: Department of Biochemistry, Dr. Ram Manohar Lohia Avadh University, Faizabad 224001, India.
authors.forename: Prabhash K
authors.initials: PK
authors.lastname: Pandey
mesh_terms: D000824:Animal Nutritional Physiological Phenomena / Q000187:drug effects; D000818:Animals; D000963:Antimetabolites / Q000494:pharmacology; D001681:Biological Assay; D001835:Body Weight / Q000187:drug effects; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007814:Larva / Q000187:drug effects; D032128:Madhuca / Q000737:chemistry*; D008970:Molecular Weight; D009036:Moths / Q000187:drug effects / Q000254:growth & development* / Q000502:physiology*; D011480:Protease Inhibitors / Q000494:pharmacology*; D059748:Proteolysis / Q000187:drug effects; D012639:Seeds / Q000737:chemistry*; D013696:Temperature; D014361:Trypsin Inhibitors / Q000494:pharmacology
chemical_list: D000963:Antimetabolites; D011480:Protease Inhibitors; D014361:Trypsin Inhibitors