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United States Department of Agriculture

Agricultural Research Service

Title: Molecular Cloning of Trypsin-Like Cdnas and Comparison of Proteinase Activities in the Salivary Glands and Gut of the Tarnished Plant Bug Lygus Lineolaris (Heteroptera: Miridae)

item Zhu, Yu Cheng
item Zeng, Fanrong
item Oppert, Brenda

Submitted to: Meeting Abstract
Publication Type: Other
Publication Acceptance Date: October 28, 2003
Publication Date: October 28, 2003
Citation: Zhu, Y., Zeng, F., Oppert, B.S. 2003. Molecular cloning of trypsin-like cdnas and comparison of proteinase activities in the salivary glands and gut of the tarnished plant bug lygus lineolaris (heteroptera: miridae). Meeting Abstract. Entomological Society of America October 2003

Technical Abstract: Using specific proteinase inhibitors, we demonstrated that serine proteinases in the tarnished plant bug, Lygus lineolaris, are major proteinases from the salivary glands and gut tissues. Gut proteinases were less sensitive to inhibition than proteinases from the salivary glands. The pH optima for azocaseinase activity in salivary glands ranged from 6.2 to 10.5, whereas the pH optima for gut proteinases was acidic for general and alkaline for tryptic proteinases. Zymogram analysis demonstrated that ~26-kDa proteinases from salivary glands were active against both gelatin and casein substrates. Three trypsin-like cDNAs, LISgP2-4, and one trypsin-like cDNA, L1GtP1, were cloned from salivary glands and gut, respectively. Deduced trypsin-like proteins from L1SgP2, LlSgP3, and LlGtP1 cDNAs shared 98-99% sequence identity with a previously reported trypsin-like precursor, whereas the trypsin-like protein of LlSgP4 shared only 44% sequence identity with all other trypsin-like proteins, indicating multi-trypsin forms are present in L. lineolaris.

Last Modified: 4/18/2015
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