Tiny Nanotubes as New Antibiotics

Release Date:
4/2/2002
Contact:
NIGMS Communications Office
301-496-7301
info@nigms.nih.gov  

One of medicine's greatest triumphs--the development of antibiotics--is steadily growing into one of medicine's greatest fears: that the infectious diseases easily vanquished decades ago will be as deadly to our grandchildren as they were to our grandparents. Within recent years, for example, hospital workers in the United States have detected strains of Staphylococcus aureus--"staph," the leading cause of hospital-acquired infections--that are resistant to every known antibiotic medicine. The race is on to find new types antibiotic medicines.

Chemistry to the rescue! Dr. M. Reza Ghadiri of The Scripps Research Institute has devised a clever chemical scheme to create a novel class of antibiotic compounds. (1) Dr. Ghadiri and his coworkers invented a way to get laboratory-made rings and strings of amino acids (peptides) to assemble themselves into channels and pores. With just the right mix of ingredients and conditions, the researchers coaxed the rings to stack on top of each other, forming a tube. The artificial tubes work as antibiotics by poking holes in bacterial membranes, making them too leaky to hold their contents. Dr. Ghadiri and his team found that the tiny tubes kill a variety of bacteria in laboratory experiments. The scientists went on to test the compounds in mice infected with a lethal dose of drug-resistant bacteria and discovered that all of the mice survived over the course of a 7-day study. In contrast, all the mice in the control group (which received no nanotubes) died within 48 hours.

This work holds great promise that a new class of nanotube peptides can be effective in treating potentially fatal antibiotic-resistant infections caused by staph and other dangerous microbes.

REFERENCE

1 Fernandez-Lopez S, Kim H-S, Choi EC, Delgado M, Granja JR, Khasanov A, Kraehenbuehl K, Long G, Weinberger DA, Wilcoxen KM, and Ghadiri MR. Antibacterial agents based on the cyclic d,l--peptide architecture. Nature 2001;412:452-5.

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Writer: Alison Davis, Science Writing Contractor