Practical and theoretical characterization of Inga laurina Kunitz inhibitor on the control of Homalinotus coriaceus

• Published in: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology Vol. 158; no. 2; pp. 164 - 172
• Main Authors: Macedo, Maria Lígia Rodrigues, Freire, Maria das Graças Machado, Franco, Octávio Luiz, Migliolo, Ludovico, de Oliveira, Caio Fernando Ramalho
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01-02-2011
• Subjects: Amino Acid Sequence; Animals; artificial diets; chymotrypsin; Cocos nucifera; Coleoptera; Curculionidae; Digestive System - enzymology; Fabaceae; growth retardation; Homology modeling; hydrolysis; Inga; Inga laurina; insect pests; Insect Proteins - isolation & purification; Insect Proteins - pharmacology; Insect Proteins - physiology; Kunitz-type proteinase inhibitor; Larva - drug effects; Larva - growth & development; larvae; Midgut proteases; Models, Molecular; Molecular Sequence Data; Peptide Hydrolases - physiology; Peptides - pharmacology; Plant Proteins - pharmacology; Protease Inhibitors - pharmacology; Protein Structure, Tertiary; Proteinase inhibitors; seeds; Sequence Alignment; soybeans; Structural Homology, Protein; Three-dimensional structure predictions; transgenic plants; trypsin; Weevils - drug effects; Weevils - enzymology; Weevils - growth & development; Three-dimensional structure predictions; Proteinase inhibitors; Coleoptera; Midgut proteases; Homology modeling
• ISSN: 1096-4959; 1879-1107
• DOI: 10.1016/j.cbpb.2010.11.005

Digestive endoprotease activities of the coconut palm weevil,
Homalinotus coriaceus (Coleoptera: Curculionidae), were characterized based on the ability of gut extracts to hydrolyze specific synthetic substrates, optimal pH, and hydrolysis sensitivity to protease inhibitors. Trypsin-like proteinases were major enzymes for
H. coriaceus, with minor activity by chymotrypsin proteinases. More importantly, gut proteinases of
H. coriaceus were inhibited by trypsin inhibitor from
Inga laurina seeds. In addition, a serine proteinase inhibitor from
I. laurina seeds demonstrated significant reduction of growth of
H. coriaceus larvae after feeding on inhibitor incorporated artificial diets. Dietary utilization experiments show that 0.05%
I. laurina trypsin inhibitor, incorporated into an artificial diet, decreases the consumption rate and fecal production of
H. coriaceus larvae. Dietary utilization experiments show that 0.05%
I. laurina trypsin inhibitor, incorporated into an artificial diet, decreases the consumption rate and fecal production of
H. coriaceus larvae. We have constructed a three-dimensional model of the trypsin inhibitor complexed with trypsin. The model was built based on its comparative homology with soybean trypsin inhibitor. Trypsin inhibitor of
I. laurina shows structural features characteristic of the Kunitz type trypsin inhibitor. In summary, these findings contribute to the development of biotechnological tools such as transgenic plants with enhanced resistance to insect pests.