title: Proteolytic activity of gut bacteria isolated from the velvet bean caterpillar Anticarsia gemmatalis.
abstract: The development of proteinase inhibitors as potential insect control agents has been constrained by insect adaptation to these compounds. The velvet bean caterpillar (Anticarsia gemmatalis) is a key soybean pest species that is well-adapted to proteinase inhibitors, particularly serine-proteinase inhibitors, which are abundant in the caterpillar host. The expression of diverse proteolytic enzymes by gut symbionts may allow the velvet bean caterpillar to circumvent proteinase inhibitors produced by the host plant. In this study, we characterized the proteolytic activity of the four nonpathogenic species of gut bacteria isolated from the velvet bean caterpillar-Bacillus cereus, Enterococcus gallinarum, Enterococcus mundtii and Staphylococcus xylosus. Two proteinase substrates, N-α-benzoyl-L-Arg-p-nitroanilide (L-BApNA) and N-α-p-tosyl-L-Arg methyl ester (L-TAME) and five proteinase inhibitors [aprotinin, E-64, ethylenediamine tetraacetic acid (EDTA), pepstatin and N-α-tosyl-L-lysine chloromethyl ketone (TLCK)] as well as CaCl2, pH and temperature profiles were used to characterize the expressed proteolytic activity of these bacterial strains in vitro. Kinetic parameters for proteolytic activity were also estimated. The results of these experiments indicated that serine- and cysteine-proteinase activities were expressed by all four gut bacteria symbionts of the velvet bean caterpillar. The cysteine- and serine-proteinase activities of these gut symbionts were distinct and different from that of gut proteinases of the caterpillar itself. This finding provides support for the potential involvement of gut symbionts in the mitigation of the negative effects of serine-proteinase inhibitors in the velvet bean caterpillar.
authors: Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil.
authors: F M
authors: FM
authors: Pilon
authors: L E
authors: LE
authors: Visôtto
authors: R N C
authors: RN
authors: Guedes
authors: M G A
authors: MG
authors: Oliveira
mesh_terms: D000818:Animals; D001409:Bacillus cereus / Q000201:enzymology; D002122:Calcium Chloride / Q000494:pharmacology; D057056:Cysteine Proteases / Q000378:metabolism*; D016983:Enterococcus / Q000201:enzymology; D041981:Gastrointestinal Tract / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009036:Moths / Q000382:microbiology; D011480:Protease Inhibitors / Q000494:pharmacology; D057057:Serine Proteases / Q000378:metabolism*; D013210:Staphylococcus / Q000201:enzymology; D013559:Symbiosis; D013696:Temperature
chemical_list: D011480:Protease Inhibitors; D057056:Cysteine Proteases; D057057:Serine Proteases; D002122:Calcium Chloride
references: Bioresour Technol. 2008 Sep;99(13):5804-13
references: 18032033
references: Exp Parasitol. 2004 Jul-Aug;107(3-4):173-82
references: 15363943
references: J Insect Physiol. 2009 Mar;55(3):185-91
references: 19061893
references: Anal Biochem. 1976 May 7;72:248-54
references: 942051
references: Environ Entomol. 2011 Oct;40(5):1111-22
references: 22251723
references: Comp Biochem Physiol B Biochem Mol Biol. 2005 Mar;140(3):369-80
references: 15694584
references: Microbiol Mol Biol Rev. 1998 Sep;62(3):597-635
references: 9729602
references: J Inorg Biochem. 1981 Dec;15(4):307-15
references: 7320713
references: Curr Microbiol. 2008 Apr;56(4):327-33
references: 18172718
references: J Chem Ecol. 2002 Oct;28(10):2045-56
references: 12474899
references: Phytochemistry. 1993 Dec;34(6):1453-66
references: 7764318
references: Can J Biochem Physiol. 1959 Dec;37:1393-9
references: 14405350
references: Proc Natl Acad Sci U S A. 1995 Aug 15;92(17):8041-5
references: 7644535
references: Biochemistry. 1970 Jul 7;9(14):2766-75
references: 5466615
references: Environ Entomol. 2009 Aug;38(4):1078-85
references: 19689886
references: Nature. 1970 Aug 15;227(5259):680-5
references: 5432063
references: J Insect Physiol. 1997 Oct;43(10):885-895
references: 12770458
references: Toxicon. 2007 Mar 15;49(4):413-22
references: 17223148
references: Comp Biochem Physiol B Biochem Mol Biol. 2010 Sep;157(1):80-7
references: 20546912
references: Curr Opin Plant Biol. 1999 Aug;2(4):268-72
references: 10458997
references: J Appl Microbiol. 2007 Dec;103(6):2664-75
references: 17973916
references: J Bacteriol. 2005 Jan;187(1):266-75
references: 15601711
references: Comp Biochem Physiol B Biochem Mol Biol. 2005 Oct;142(2):192-200
references: 16102991
references: Arch Biochem Biophys. 2003 Dec 1;420(1):1-8
references: 14622969
references: Annu Rev Entomol. 2006;51:45-66
references: 16332203
references: Arch Biochem Biophys. 1961 Nov;95:271-8
references: 13890599
references: Annu Rev Entomol. 2004;49:71-92
references: 14651457
references: Comp Biochem Physiol B Biochem Mol Biol. 2010 Jan;155(1):12-9
references: 19835976
references: Toxicon. 2002 Nov;40(11):1515-39
references: 12419503