Co-Localization of Crotamine with Internal Membranes and Accentuated Accumulation in Tumor Cells

Crotamine is a highly cationic; cysteine rich, cross-linked, low molecular mass cell penetrating peptide (CPP) from the venom of the South American rattlesnake. Potential application of crotamine in biomedicine may require its large-scale purification. To overcome difficulties related with the purification of natural crotamine (nCrot) we aimed in the present study to synthesize and characterize a crotamine analog (sCrot) as well investigate its CPP activity. Mass spectrometry analysis demonstrates that sCrot and nCrot have equal molecular mass and biological function-the capacity to induce spastic paralysis in the hind limbs in mice. sCrot CPP activity was evaluated in a wide range of tumor and non-tumor cell tests performed at different time points. We demonstrate that sCrot-Cy3 showed distinct co-localization patterns with intracellular membranes inside the tumor and non-tumor cells. Time-lapse microscopy and quantification of sCrot-Cy3 fluorescence signalss in living tumor versus non-tumor cells revealed a significant statistical difference in the fluorescence intensity observed in tumor cells. These data suggest a possible use of sCrot as a molecular probe for tumor cells, as well as, for the selective delivery of anticancer molecules into these tumors.