As shown before, the intact protein can be found in Rhodnius hemolymph 30 min after its ingestion by the insects ( Staniscuaski et al., 2010). It is not known yet how and where this absorption occurs. In Bombyx mori, it CP-868596 nmr has been demonstrated that the dietary mulberry urease is absorbed from the insect gut into the hemolymph and the presence of urease binding molecule(s) in the gut brush border membrane that would mediate this process was postulated ( Kurahashi et al., 2005). The identity of such molecule(s) has not been investigated so far. Fig. 6 summarizes the possible effects of chemical
modifications on the JBU biological properties investigated here. JBU fed to the insects can follow two pathways: 1) be absorbed into the hemolymph and/or 2) be transported to the insect posterior midgut, where it is digested, generating toxic peptide(s), one of which is Jaburetox (Staniscuaski and Carlini, 2012). Since JBU-Lys is hydrolyzed similarly to the native protein, we postulate that the modification of lysines probably impairs JBU absorption into the hemolymph and/or its action on target tissues, including the Malpighian tubules. In JBU-Ac, on the other hand, the release of toxic peptide(s) upon hydrolysis by insect’s enzymes is blocked, reducing the toxicity of the protein. Since the intact protein can still be absorbed into the hemolymph, a residual toxicity
is observed. There was no significant difference in the lethality between the two derivatives forms of JBU, corroborating the idea that a combinatory effect of both, peptides and intact protein, is relevant to its entomotoxic property. C. ensiformis ureases are complex proteins with learn more several biological activities. The entomotoxic activity
is of great interest, since the search for natural insecticides, with none or reduced threat to the environment or to human health is an attractive alternative to synthetic chemical insecticides for pest management ( Isman, 2006). Altogether, the data herein contributed to our understanding of structure/function of the urease entomotoxic activity and represent an advance on the possible use of ureases and/or their derived-peptides as biological tools in pest management. All the authors declare that: Etomidate the paper has not been previously published in whole or in part and is not currently being considered for publication elsewhere; all authors have contributed significantly to the execution, analysis and writing of the paper. This project was supported by Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq), Coordenação de Aperfeiçoamento de Pessoal de Nivel Superior (CAPES) and Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS). “
“On page 505, the paragraph starting as “McLachlan et al. (2005), Kekre et al. (2005) and Siedlakowski et al. (2008) studied the effects of Pancratistatin (PST)…” describes the toxins produced by the plant Pancratium littorale, also known as spider lilly.