Bioassays of the snake protein extracts derived from the cutaneous mucus of the prey species.

The chemoattractivity of the crude mucus extracts was assessed according to a standard “all-or-none” snake bioassay based on a non-biological lure coated with the tested sample as in [9]. The test was considered positive if the snake attacked the lure within 20 sec after the first lure-directed tongue flick. The test was considered negative in any other circumstances. A/B corresponds to the number of positive tests/total tests. X/Y corresponds to the number of positive tests/total tests after the proteinase K treatment.