ARS | Publication request: QUALITATIVE AND QUANTITATIVE PROTEASE ACTIVITIES IN MIDGUT AND SALIVARY GLANDS OF LYGUS HESPERUS

Submitted to: Annals of the Entomological Society of America
Publication Type: Abstract Only
Publication Acceptance Date: August 5, 2000
Publication Date: N/A

Technical Abstract: Specificities of protease activities in Lygus hesperus midgut and salivary gland were determined by incubating tissue homogenates with peptides of known structure in the presence of inhibitors of specific classes of protease activity. Samples were analyzed by HPLC and MALDI. To determine the quantitative contribution of each class of protease activity to the overall activity, fluorescently-labeled protein was incubated with homogenates in the presence or absence of these inhibitors. In general, cysteine proteases were found to contribute significantly to overall activity, and total protease activity of salivary gland homogenates greatly exceeded that of midgut homogenates. In support of our biochemical studies, we observed a significant reduction in nymphal mass when Lygus neonates were fed the specific cysteine protease inhibitor, E-64.