New techniques for stapling peptides could spur development of drugs for cancer, other diseases

Researchers at the University at Buffalo have devised two new ways of "stapling" peptide helices to prevent these medically important molecules from losing their shape and degrading in the presence of enzymes.

Chemist Qing Lin has devised two new ways of "stapling" peptides, which could lead to new treatments for a health problems such as cancer and inflammatory, metabolic and infectious diseases.

The discovery could help speed the development of peptide-based drugs against diseases including cancer. UB scientists say the methods they pioneered are simpler than existing techniques, one of which employs an expensive ruthenium catalyst to connect chemical side chains that protrude from the main body of helical peptides.

"There's a lot of potential here. Our chemistry is unique," said Qing Lin, the UB assistant professor of chemistry who led the research. "There are not that many new drug targets out there today, which partly explains the declining number of FDA-approved new drugs in recent years. So there's a need to come up with new technologies that can overcome this barrier. To this end, stapled peptides could open a whole host of new targets for therapies."

Stapled peptides work as treatments against disease by binding tightly to target proteins within cells, thus disrupting specific protein-protein interactions that regulate many biological processes, including response to stress, signaling within cells, and cell death.

In their native state, peptides -- short strings of amino acids -- shift between different shapes, including a helix, sheet and random coil. Stapling the peptides' side chains encourages the peptides to adopt and stay in a helix, which enables them to enter cells more easily. The helical conformation also makes it more difficult for enzymes to break the peptides down, Lin said.

The two processes Lin's team developed for stapling peptides are efficient, producing stapled peptides in high yields, said Timothy Dee, a commercialisation manager for UB's Office of Science, Technology Transfer and Economic Outreach (STOR). Through STOR, UB is applying for patents to cover both stapling methods.