The aims of our work were therefore to obtain monoclonal antibodies directed to biologically significant toxin epitopes expressed on B. atrox lethal toxins. The corresponding hybridomas will be used to develop humanized or antibody fragments as nonimmunogenic in vivo biopharmaceutical endowed with superior biodistribution and blood clearance properties. This work was supported by FAPERJ, CNPq. WDS is supported by grants from the following agencies: CNPq, Bolsa de Produtividade, Nível A, Proc. No: 301836/2005 – 1; FAPERJ “Programa – Cientistas de Nosso Estado”, Proc. No: E – 26/100.628/200; FAPESP, Proc. No: 09/52804 – 0 and INCTTOX program of the CNPq and FAPESP.

The authors

are grateful to Instituto http://www.selleckchem.com/products/Vincristine-Sulfate.html Butantan for providing B. atrox venom and horse F(ab′)2 anti-bothropic antivenom. This manuscript JNK inhibitor was reviewed by a professional science editor and by a native English-speaking copy editor to improve readability. “
“Ureases (urea amidohydrolase; EC 3.5.1.5) are nickel-dependent enzymes that catalyze the hydrolysis of urea to ammonia and carbon dioxide (Dixon et al., 1975). Ureases have been isolated from a wide variety of organisms including plants, fungi and bacteria. In plants, ureases are homotrimers or homohexamers of a ∼90 kDa subunit and supposedly participate in the use of urea as nitrogen source (Carlini and Polacco, 2008). Evidences pointing to a possible involvement of ureases in the plant defense against MRIP some insect pests and phytopathogens have been documented (Carlini and Grossi-de-Sa, 2002; Carlini and Polacco, 2008; Staniscuaski and Carlini, 2012). Thus, newly described

properties of plant and microbial ureases, such as entomotoxic and fungitoxic activities, have widened the proposed physiological roles of ureases (Real-Guerra et al., 2013). In Canavalia ensiformis (Leguminosae) three urease isoforms were identified: Jackbean urease (JBU), Jackbean urease II (JBUre-II) and canatoxin (CNTX). These proteins were shown to present several biological effects, including toxicity to insects and fungi ( Becker-Ritt et al., 2007; Follmer et al., 2004; Mulinari et al., 2011; Postal et al., 2012; Staniscuaski et al., 2005, 2009, 2010). These biological activities are completely independent from the ureolytic activity ( Follmer et al., 2004; Mulinari et al., 2011; Postal et al., 2012). Elucidation of which domain is related to each biological activity could lead to the development of several urease-based biotechnological tools. One of the biologically active domains of Jackbean ureases, the one responsible for its insecticidal activity, has been identified. It is a ∼10 kDa fragment released by cleavage promoted by insect digestive enzymes ( Carlini et al., 1997; Ferreira-DaSilva et al., 2000).