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Analysis of hemolymph proteinase 16 from an insect, Manduca sexta
Author(s) -
Christen Jayne,
Kanost Michael R.
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.677.1
Subject(s) - hemolymph , manduca sexta , prophenoloxidase , biology , serine protease , biochemistry , western blot , serine , manduca , microbiology and biotechnology , sphingidae , sf9 , innate immune system , recombinant dna , spodoptera , insect , protease , enzyme , botany , receptor , gene
Hemolymph of the caterpillar, Manduca sexta , contains at least twenty‐five serine proteinases, some of which function in aspects of innate immune responses. These hemolymph proteinases are synthesized as zymogens and remain inactive until proteolytic cleavage occurs. Hemolymph proteinase 16 (HP16) is a 47 kDa protein that has a carboxyl‐terminal S1 family serine proteinase domain with predicted chymotrypsin/elastase‐like specificity. The amino‐terminal 170 residues of HP16 have no significant match to any characterized protein. The goal of this project was to study the expression of HP16 during larval development and in response to immune challenge. Western blot analysis of plasma from naïve insects showed that expression levels of HP16 were the highest during the wandering, prepupal, and pupal stages. Real‐time PCR analysis demonstrated an increase in HP16 transcript level in fat body of wandering stage insects. Fifth instar larvae that were immune challenged by injection of Escherichia coli or Micrococcus luteus showed an increase in HP16 expression levels in plasma and HP16 mRNA in fat body when compared to saline‐injected larvae. We have developed a baculovirus for the expression of recombinant HP16 and are currently working on purification of this protein for experiments to investigate its proteolytic activity and biological function. Supported by NIH grant GM41247.