Research | Call it a leap of science: With the help of supercomputers Penn researchers have created compounds that reproduce the bacteria-battling effects of magainin, a peptide first discovered in frog skin.
“We’re trying to develop an antibiotic of the last resort, since resistance to antibiotics has become so widespread,” says Dr. William DeGrado, professor of biochemistry and biophysics and co-principal investigator in the study with Dr. Michael Klein and Dr. Jeffrey Winkler, professors of chemistry; and Dr. Robert Doerksen, a post-doctoral researcher. “Unlike many antibiotics on the market, it would be very difficult for bacteria to develop resistance to this one.” It targets the cell membranes of bacteria rather than a single protein or enzyme that can mutate, he explains. Clinical trials are still about a year off.
Their research builds upon the work of Dr. Michael Zasloff, now an adjunct professor of biochemistry and biophysics at Penn. Zasloff discovered magainin in the late 1980s while performing surgery on African clawed frogs. After suturing the animals, he would put them back in a tank of bacteria-infested water, where, to his surprise, they never got sick, DeGrado says. Isolating peptides in the frogs’ skin, Zasloff found magainin, an antibacterial substance common to many plants and animals.
“If you were a moth, this would be pretty much your whole immune system,” DeGrado says. In humans, “it’s really a minor component at this stage, because we’ve evolved antibodies and T-cells and other neat things; nevertheless, it’s still part of our innate immune system.”
According to DeGrado, another application of the magainin research that is “taking a backseat” to the antibiotic is the development of inexpensive polymers that could be applied to the surface of materials to keep them bacteria-free. —S.F.
