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United States Department of Agriculture

Agricultural Research Service

Title: Thiol-Activated Serine Proteinases from Nymphal Hemolymph of the African Migratory Locust, Locusta Migratoria Migratorioides

Authors
item Hanzon, Jacob - THE HEBREW U OF JERUSALEM
item Smirnoff, Patricia - THE HEBREW U OF JERUSALEM
item Applebaum, Shalom - THE HEBREW U OF JERUSALEM
item Mattoo, Autar
item Birk, Yehudith - THE HEBREW U OF JERUSALEM

Submitted to: Archives Of Biochemistry and Biophysics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 15, 2004
Publication Date: June 15, 2004
Citation: Hanzon, J., Smirnoff, P., Applebaum, S.W., Mattoo, A.K., and Birk, Y. 2003. Thiol-activated serine proteinases from nymphal hemolymph of the African migratory locust, Locusta migratoria migratorioides. Arch. Biochem. Biophys. 410:83-88.

Technical Abstract: Two unique serine proteinase isoenzymes (LmHP-1 and LmHP-2) were isolated from the hemolymph of African migratory locust (Locusta migratoria migratorioides) nymphs. Both have a molecular mass of about 23 kDa and are activated by thiol-reducing agents. PMSF abolishes enzymes activity only after thiol activation, while the cysteine proteinase inhibitors E-64, iodoacetamide, and heavy metals fail to inhibit the thiol-activated enzymes. The N-terminal sequence was determined for the more-abundant LmHP-2 isoenzyme. It exhibits partial homology to that of other insect serine proteinases and similar substrate specificity and inhibition by the synthetic and protein trypsin inhibitors pABA, TLCK, BBI, and STI. The locust trypsins LmHP-1 and LmHP-2 constitute a new category of serine proteases wherein the active site of the enzyme is exposed by thiol activation without cleavage of peptide bonds.

Last Modified: 9/23/2014
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