A positive feedback mechanism in the Manduca sexta prophenoloxidase activation system
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چکیده
منابع مشابه
Manduca sexta serpin-3 regulates prophenoloxidase activation in response to infection by inhibiting prophenoloxidase-activating proteinases.
Many serine proteinase inhibitors of the serpin superfamily have evolved in vertebrates and invertebrates to regulate serine proteinase cascades that mediate the host defense responses. We have isolated an immune-responsive serpin from the tobacco hornworm, Manduca sexta. This inhibitor, M. sexta serpin-3, contains a reactive site loop strikingly similar to the proteolytic activation site in pr...
متن کاملA pattern recognition serine proteinase triggers the prophenoloxidase activation cascade in the tobacco hornworm, Manduca sexta.
A serine proteinase cascade in insect hemolymph mediates prophenoloxidase activation, a defense mechanism against pathogen or parasite infection. Little is known regarding its initiating proteinase or how this enzyme is activated in response to invading microorganisms. We have isolated from the tobacco hornworm, Manduca sexta, a cDNA encoding a modular protein designated hemolymph proteinase 14...
متن کاملCrystal structure of Manduca sexta prophenoloxidase provides insights into the mechanism of type 3 copper enzymes.
Arthropod phenoloxidase (PO) generates quinones and other toxic compounds to sequester and kill pathogens during innate immune responses. It is also involved in wound healing and other physiological processes. Insect PO is activated from its inactive precursor, prophenoloxidase (PPO), by specific proteolysis via a serine protease cascade. Here, we report the crystal structure of PPO from a lepi...
متن کاملCavitation in the embryonic tracheal system of Manduca sexta.
Insect tracheae form during embryonic development and initially contain liquid, which impedes transport of oxygen and carbon dioxide. Only later do tracheae fill with gas and come to support high rates of gas flux. This liquid-to-gas transition is poorly understood. Using eggs of the sphingid moth Manduca sexta, we show that longitudinal tracheae in embryos fill with gas in less than 5 s, witho...
متن کاملInteraction between Manduca sexta allatotropin and manduca sexta allatostatin in the fall armyworm Spodoptera frugiperda.
A peptide that strongly stimulates juvenile hormone (JH) biosynthesis in vitro by the corpora allata (CA) was purified from methanolic brain extracts of adult Spodoptera frugiperda. Using HPLC separation followed by Edman degradation and mass spectrometry, the peptide was identified as Manduca sexta allatotropin (Mas-AT). Treating the CA from adult S. frugiperda with synthetic Mas-AT (at 10(-6)...
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ژورنال
عنوان ژورنال: Insect Biochemistry and Molecular Biology
سال: 2008
ISSN: 0965-1748
DOI: 10.1016/j.ibmb.2008.04.008