The crude venom showed haemorrhagic, oedematous and myotoxic activity. A241_9 is predicted with a PP of 0.99 to be a haemotoxin Pexidartinib nmr while B344_LT2 is predicted (PP = 0.66) to be a myotoxin, thus the demonstrated activity of the whole venom is entirely consistent with the predictions of the functional activity of its main constituent PLA2s. Similarly, the activity of the crude venom from B469,
B475, B526, B5, B33 and B67 is entirely consistent with the predicted activity of at least some of the major PLA2 toxins that they contain. The activity of the venom from B8 (Cryptelytrops insularis) is partly consistent, in that it is known to contain isoforms that have predicted activities
that are not shown by the whole venom. However, in this case, the only major toxin (matching B5_set2 in MW) is predicted to be haemotoxic (PP = 0.94), which matches the activity of the crude venom, while the isoform matching A229_LT5 (with predicted myotoxic activity) is only a minor constituent of the venom (data from the LC–ES–MS). A more inexplicable inconsistency between predicted and demonstrated functions is found in the case of the crude venom of A229 (Cryptelytrops albolabris), which showed only slight haemorrhagic activity and no other activity. From the LC–ES–MS profile, we know that this venom contains seven major isoforms Selleck SRT1720 of PLA2, six of which have been identified in this study (these are A229_LT5, A229_LT11, A241_28, B464_LT11, B480_UP, and B769_gpB), and another which remains unidentified. Of these, PAK6 A229_LT11, A241_28 and B769_gpB have predicted haemotoxic activity (PP > 0.9), but B464_LT11 has predicted neurotoxic activity (PP = 0.82) and A229_LT5 has predicted myotoxic activity (PP = 0.6). There may be synergistic effects among this complex cocktail of similar toxins that
masks some of these activities in the crude venom. This may also be the reason for a dramatic inconsistency between the results of the functional assays on whole venom and the isolated toxins in the case of D31778, which was isolated from the venom of T221 (V. stejnegeri). The isolated toxin shows very high neurotoxic activity which exceeded that of the positive control used, yet the whole venom shows no such activity. In this case, the neurotoxicity of D31778 also fails to be predicted by the DFA (which in fact predicts it to be a haemotoxin with very high probability), and in the PNJ tree, is clustered among other isoforms similarly predicted to be haemotoxins. It is therefore extremely interesting that another isoform from V. stejnegeri (P81478) has been independently demonstrated to be neurotoxic ( Fukagawa et al., 1993), yet also fails to be predicted as such by the current methods.