peruvianus (Hemiptera), as described in Staniscuaski et al. (2005). Briefly, JBU and its derivatives were fed to the insects by adding the freeze-dried protein (at final concentration of 0.1% w/w) to their cotton seed check details meal diet. The toxicity was expressed as daily survival rate during a period of 17 days. For the in vitro hydrolysis of JBU, a homogenate of D. peruvianus intestines was used as source of proteolytic enzymes as described by Staniscuaski et al. (2005). Briefly, whole intestines of fourth instars nymphs were removed, homogenized, and centrifuged at 4 °C at 12,000 × g for 5 min. The supernatant was kept frozen at −20 °C until the enzymatic assays. To determine the enzymatic activity,

the homogenate (protein final concentration of INK 128 solubility dmso 1.0 unit of absorbance at 280 nm) was incubated with azocasein (final concentration of 0.5%). One unit of enzymatic activity was defined as the amount of enzyme releasing 1.0 unit of absorbance at 420 nm (A420) of acid-soluble peptides per hour at 37 °C, at pH 5.6. Digestion of JBU with D. peruvianus proteinases was performed as described by Piovesan et al. (2008), using a ratio of 0.5 mU of homogenate

to 1.0 μg of urease, incubated in 5 mM ammonium formate, pH 5.6, at 37 °C, under continuous stirring. The enzyme preparation was added to the urease solution in two aliquots, separated by a 12 h interval. The reaction was stopped by freeze-drying the samples. The hydrolysis was analyzed by SDS-PAGE on gradient gels (8–20%). The 3D structure of JBU (PDB ID: 3LA4; Balasubramanian and Ponnuraj, 2010) was downloaded from the Protein Data Bank (http://www.rcsb.org). The PyMOL Molecular Graphics System (Schrödinger, LLC) was used to visualize the structure of JBU, to localize specific amino acids residues and domains within the protein and to generate the figures. The effect of

the chemical modifications Methane monooxygenase on JBU activities on weight loss and Malpighian tubules secretion were assessed using R. prolixus as a model. The insects were kindly provided by Dr. Hatisaburo Masuda and Dr. Pedro L. Oliveira, Institute of Medical Biochemistry, Universidade Federal do Rio de Janeiro, RJ, Brazil. Insects (4th instars) were fed on saline solution containing 1 mM ATP, supplemented with buffer or the test proteins (dose of 2 μg/mg of insect), for 15 min and weighted right after. Weight loss was assessed at 0, 1.5, 3, 20, 24 and 48 h after feeding. The Ramsay assay with Malpighian tubules was used to evaluate the fluid secretion rate, performed as described by Staniscuaski et al. (2009). Results are expressed as mean ± standard error. Significance of differences between means was determined using ANOVA followed by Dunnett test (GraphPad Instat software). Data were considered statistically different when p < 0.05. Detailed information for each assay is given in the figures captions. After the derivatization reaction, more than 90% of JBU-Lys or JBU-Ac was recovered.