Journal of Pest Science (2012) 85, 117-123

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E.G. Mendonça, M.G.A. Oliveira, L.E. Visôtto and R.N.C. Guedes (2012)
Midgut cysteine-proteinase activity in the velvetbean caterpillar (Anticarsia gemmatalis (Hübner))
Journal of Pest Science 85 (1), 117-123
Abstract: Proteinase inhibitors are currently targeted as potential insect control agents, but adaptation to proteinase inhibitors is a recognized limitation to such approach requiring the understanding of how phytophagous species can cope with such compounds. The velvetbean caterpillar (Anticarsia gemmatalis) is a key pest of soybean and well-adapted to its host proteinase inhibitors, which is rich in serine-proteinase inhibitors, particularly trypsin-like proteinase inhibitors. As the expression of cysteine proteinases in the midgut of the velvetbean caterpillar is a potential adaptation to circumvent its host defense, we assessed and characterized the digestive cysteine-proteinase activity from velvetbean caterpillars. Significant soluble and membrane-bound proteolytic activity was obtained and was consistent with those of cysteine proteinases based on the substrate and inhibitors used for their characterization. The K m and V max values obtained were 2.35 ± 0.50 mM and 40.89 ± 6.68 nmol min−1 mg−1 for the soluble proteinases and 0.33 ± 0.03 mM and 24.54 ± 0.67 nmol min−1 mg−1 for the membrane-bound proteinases, range of values also consistent with cysteine proteinases. Therefore, the proteolytic activity observed in the velvetbean caterpillar midgut is consistent with that of cysteine proteinases providing preliminary support for the contention of their potential involvement mitigating the negative effects of serine-protease inhibitors in this species.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Raul Narciso C. Guedes

Research topic(s) for pests/diseases/weeds:
molecular biology - genes
control - general

Pest and/or beneficial records:

Beneficial Pest/Disease/Weed Crop/Product Country Quarant.

Anticarsia gemmatalis