Published by Elsevier B.V. The investigation of antibacterial activity of three-finger cobra cytotoxins towards Gram-negative and Gram-positive bacteria showed no activity against the former species, whereas M. luteus from the latter ones was the most susceptible to cytotoxins. A correlation was revealed between this activity and hydrophobicity of the toxins (HTL scores), total charge and its distribution over the toxin molecule: the absence of Glu?16 residue and the presence of positively charged residues (Lys30/His31) in the tip of the loop 2.