Recombinant expression and characterization of a variant of the enzime Sl-CathL from the sugarcane weevil, Sphenophorus levis

• Grant number: 13/05982-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2013
• End date: June 30, 2014
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Flavio Henrique da Silva
• Grantee: Bruna Samhan Archangelo
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Sugarcane is one of the most important crops for the Brazilian economy, for both sugar and ethanol production. The pest attack is still an important factor affecting productivity in the fields. The occurrence of the sugarcane weevil (Sphenophorus levis), a major pest of sugar cane, has increased significantly in São Paulo. There is no effective method to control this pest, which reinforces its importance and relevance of studies of its biology. In our laboratory we performed a transcriptomic study of larvae of S. levis, in which several variants of the main digestive enzyme Sl-CathL were identified and grouped. In some, the cysteine residue of the active site of the Sl-CathlL is replaced by a serine, which apparently implies the loss of function of these variants and may be related to the insect defense mechanisms. The objective of this is the recombinant production of the altered Cath-L (Sl-CathL-CS) in the Pichia pastoris for further characterization of its enzymatic profile. This study will permit to evaluate the ability of the Sl-CathL-CS to increase the activity of other variants in the presence of cystatins. We expect to contribute to the understanding of the physiological role of this protein and for future establishment of varieties of sugar cane more resistant to the insect. (AU)