Dov Borovsky, dobo@mail.ifas.ufl.edu1, Lotte Dehing, lottedehing@hotmail.com1, Donna, A. Iannotti, DAIannotti@ifas.ufl.edu1, Timothy Morris, Timothy_Morris@hotmail.com1, Charles A. Powell2, and Robert G. Shatters3. (1) University of Florida, IFAS, Florida Medical Entomology Laboratory, 200 9th St SE, Vero Beach, FL, (2) University of Florida, IFAS, Indian River Research and Education Center, Fort Pierce, FL, (3) USDA-ARS, U. S. Horticultural Research Laboratory, 2001 South Rock Road, Fort Pierce, FL
Cathepsin L and trypsin are the major proteolytic enzymes that control digestion in the gut of the citrus weevil Diaprepes abbreviatus. Since the optimal activity of Cathepsin L is at pH 5.0 and the pH of the Weevil’s gut is at pH 6.5, which significantly depresses the enzymatic activity of cathepsin L we studied the possibility that the enzyme is protected from the high pH by a chaperone. A possible chaperone was identified from sequenced cDNA library of adult D. abbreviatus. Based on this sequence we amplified by PCR a homologous dsDNA from the larval gut . The dsDNA was cloned, sequenced and expressed in bacteria. The expressed chaperone-like protein was characterized and incubated with Cathepsin L to find out if it stabilizes the enzyme at the pH of the larval gut. These results and the physiological role of the chaperone-like protein will be discussed.
Keywords: Chaperone, Cathepsin L
