Monday, 1 October 2012

How Can Scorpions Save Us?

I am not talking about the 80's band the Scorpions with classic hits like:     I am talking about the the little ectotherm canibals, with a nasty stinger that live in the dessert, give people nightmares and occasionally give people a larger sting of a giant hospital bill. 

However, the venom from scorpion bites could be a double edged sword since it could also people against drug resistant bacteria.  Scorpion venom has phospholipase A2 a enzyme protein that destroys fat or lipid molecules and small proteins or peptides that have an antimicrobial effects.  Antimicrobial means that it can destroy microbes e.g. bacteria.  Why is this awesome?  Well these bacteria do not react any sort of antibody so there is little doctors have at their disposal.  Scorpion venom could easily help.  (Likely they could just order the peptide in large quantities) and be very effective to destroy the bacteria as shown in this Wired (July 11th) by Robert Hancock of the University of British Columbia.

In the video this is one way that antimicrobial peptides can penetrate and destroy bacterial cell walls.  There are actually several ways e.g. carpet model, leaky slit model, barrel-stave, or toroidal pore model. 

What does this have to do with surface tension?  The lipid molecules in a bacterial membrane (or normal membrane for that matter) have a tensile strength that prevents substances from getting into the membrane.  Several bacterial membranes have a net positive charge and the antimicrobial peptides can bind and destroy the membrane without 1) any disruption of normal human cells 2) use of antibiotics

There are a nearly infinite number of combinations that can make good antimicrobial peptides.  Several of the best ones are evolved from nature and are listed on this database.  A good way to test them before subjecting the antimicrobial peptides and yourself to deadly bacteria is to use a Delta-Pi or Delta-Pi 4 surface tension device.  Both of these units have helped researchers to understand the penetration and effectiveness of antimicrobial peptide to disrupt the bacterial membrane.