Abstract

MOLINA V, DIANA; BLANCO-LABRA, ALEJANDRO  and  ZAMORA E., HUMBERTO. Plant protease inhibitors effective against aspartic proteases from Coffee Berry Borer (Hypothenemus hampei). Rev. Colomb. Entomol. [online]. 2011, vol.37, n.2, pp.183-191. ISSN 0120-0488.

The coffee berry borer, Hypothenemus hampei, is one of the most devastating coffee pests (Coffea arabica). Aspartic proteases were identified in protein extracts of adult insects, showing two bands of proteolytic activity in zymograms and a maximum activity at pH 2.5 in the spectrophotometric assays. Considering its inhibition by pepstatin A and hemoglobin hydrolysis this enzyme was classified as cathepsin D. Seeds extracts of Lupinus bogotensis, Brachiaria humidicola, Amaranthus hypochondriacus, Phaseolus acutifolius, Phaseolus coccineus, Hyptis suaveolens, Centrosema pubescens, and Trifolium repens were evaluated to identify aspartic protease inhibitors. The greatest inhibitory activity of aspartic proteases was found in L. bogotensis extract with a specific activity of 74.1 IU/mg, compared with extracts of H. suaveolens, B. humidicola, and A. hypochondriacus that showed a lower inhibition of aspartic proteases. Other protein extracts did not inhibit aspartic protease activity. The proteolytic activity of H. hampei was inhibited by 90% with 100 mg of crude extract of L. bogotensis, whereas it took 1 mg of crude extract of H. suaveolens and B. humidicola to inhibit the activity at 70 and 60% respectively. The zymograms identified potential protease inhibitors in extracts of L. bogotensis, H. suaveolens, B. humidicola and A. hypochondriacus that blocked in vitro activity of aspartic proteases of the insect. The expression of protease inhibitor genes in coffee is an alternative to obtain resistant varieties.

Keywords : Lupinus bogotensis; Leguminosae; Aspartic protease inhibitor; Aspartic protease; Hypothenemus hampei.

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