Manduca sexta serpin-6 regulates immune serine proteinases PAP-3 and HP8. cDNA cloning, protein expression, inhibition kinetics, and function elucidation.

ABSTRACT: Analogous to blood coagulation and complement activation in mammals, some insect defense responses (e.g. prophenoloxidase (proPO) activation and Toll pathway initiation) are mediated by serine proteinase cascades and regulated by serpins in hemolymph. We recently isolated Manduca sexta serpin-6 from hemolymph of the bacteria-challenged larvae, which selectively inhibited proPO-activating proteinase-3 (PAP-3) (Wang, Y., and Jiang, H. (2004) Insect Biochem. Mol. Biol. 34, 387-395). To further characterize its structure and function, we cloned serpin-6 from an induced fat body cDNA library using a PCR-derived probe. M. sexta serpin-6 is 55% similar in amino acid sequence to Drosophila melanogaster serpin-5, an immune-responsive protein. We produced serpin-6 in an Escherichia coli expression s

SUBMITTER: Zou Z 

PROVIDER: S-EPMC2047605 | biostudies-literature | 2005 Apr

REPOSITORIES: biostudies-literature