The total ion count (TIC) chromatograms of LC-MS/MS runs and the plots of elution times from LC versus ion intensity showed different profiles for the sting venom and skin mucus. A total of 66 proteins were detected in both samples, of these 46 were presents in sting venom and 33 in skin mucus. Moreover, we identified 13 common proteins in both the samples as a H2ab protein (gi148227934), chain B crystal structure of oxy-hemoglobin
(gi209156416), enzyme APOBEC-2 (gi209736158), a protein similar to melanotransferrin precursor (gi16343451) and WAP65 (gi158021040) (Fig. 1A and B, and supplement Table 2). Although a number of proteins selleck compound were detected by a single credible peptide, these detections are still highly confident, since almost all these proteins had an unused score of greater than or equal to two, which corresponds to 99% detection confidence. The chromatographic
separation by analytical RP-HPLC of C. spixii sting venom and skin mucus is presented in Fig. 2. Although some similarities of retention times and relative concentrations of certain components can be observed, the overall profiles are quite distinct. Fractionation of sting venom resulted in 11 fractions called Fv1 to Fv11 ( Fig. 2A) while the skin mucus resulted in 13 fractions (Fm1 to Fm13) ( Fig. 2B). During the first 20 min of HPLC separation (square with dotted line) we observed Protein Tyrosine Kinase inhibitor that the peptide fractions are more intense in the skin mucus, OSBPL9 and the proteic components separated around 30–40 min retention time (squared with full line) were
more intense in the sting venom. Next we analyzed sting venom and skin mucus by SDS-PAGE (12% gel) applying 10 micrograms of both sample of venoms. The sting venom profiles under reducing (data not shown) and non-reducing conditions are identical and in Fig. 2C we obtained 7 bands in the sting venom and 9 in the skin mucus. Sting venom and skin mucus presented common bands with high mass, around 40–60 kDa and 13–15 kDa. This finding was confirmed by of LC-MS/MS (supplement Table 2). Moreover, as an interesting and different feature of sting venom we observed the presence of 3 bands of 26, 60 and 70 kDa which were lacking in the skin mucus. Peptide fractions obtained from the sting venom (1–5) and skin mucus (1–7) were analyzed by MALDI-ToF mass spectrometry. As shown in Table 1, the peptide fractions found in the sting venom showed a higher number of components compared with the fractions collected from the skin mucus. In addition, the peptide fractions found in the sting venom are rich in components with masses ranging from 1185.63 to 2579.53 Da. No mass was detected in the fraction Fm5 from skin mucus, which presented components with molecular weight around 869.25–2446.16 Da. In addition, fractions Fm1 and FM2 presented as pure components with 1515.62 and 1515.51 Da, respectively.