Properties of purified gut trypsin from Helicoverpa zea adapted to proteinase inhibitors
| Autor: | Volpicella M. 1, Ceci L.R. 2, Cordewener J. 3, America T. 3, Gallerani R. 1, Bode W. 4, Jongsma M.A. 3, Beekwilder J. 3 |
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| Jazyk: | angličtina |
| Rok vydání: | 2003 |
| Předmět: | |
| Zdroj: | European journal of biochemistry 270 (2003): 10–19. doi:10.1046/j.1432-1033.2003.03368.x info:cnr-pdr/source/autori:Volpicella M. 1, Ceci L.R. 2, Cordewener J. 3, America T. 3, Gallerani R. 1, Bode W. 4, Jongsma M.A. 3 and Beekwilder J. 3/titolo:Properties of purified gut trypsin from Helicoverpa zea adapted to proteinase inhibitors/doi:10.1046%2Fj.1432-1033.2003.03368.x/rivista:European journal of biochemistry (Print)/anno:2003/pagina_da:10/pagina_a:19/intervallo_pagine:10–19/volume:270 |
| DOI: | 10.1046/j.1432-1033.2003.03368.x |
| Popis: | Pest insects such as Helicoverpa spp. frequently feed on plants expressing protease inhibitors. Apparently, their digestive system can adapt to the presence of protease inhibitors. To study this, a trypsin enzyme was purified from the gut of insects that were raised on an inhibitor-containing diet. The amino-acid sequence of this enzyme was analysed by tandem MS, which allowed assignment of 66% of the mature protein amino acid sequence. This trypsin, called HzTrypsin-S, corresponded to a known cDNA sequence from Helicoverpa. The amino acid sequence is closely related (76% identical) to that of a trypsin, HzTrypsin-C, which was purified and identified in a similar way from insects raised on a diet without additional inhibitor. The digestive properties of HzTrypsin-S and HzTrypsin-C were compared. Both trypsins appeared to be equally efficient in degrading protein. Four typical plant inhibitors were tested in enzymatic measurements. HzTrypsin-S could not be inhibited by > 1000-fold molar excess of any of these. The same inhibitors inhibited HzTrypsin-C with apparent equilibrium dissociation constants ranging from 1 nm to 30 nm. Thus, HzTrypsin-S seems to allow the insect to overcome different defensive proteinase inhibitors in plants. |
| Databáze: | OpenAIRE |
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