Research Communications

Protein Sleuths 

Analytical chemistry technique could help scientists select new drug candidates

October 27, 2011

Pharmaceutical companies are increasingly seeking to create protein-based drugs that are less toxic and more effective than conventional treatments. A new technique designed by Ohio University scientist Hao Chen could aid those drug development efforts.

Analytical chemists use a technique called mass spectrometry (MS) to determine the mass, structure, and composition of molecules. Chen pairs this traditional tool with electrochemistry (EC) using a technique called desorption electrospray ionization (DESI) to break apart the disulfide bonds of protein molecules to better understand their characteristics. This may be important for the synthesis of protein drugs, Chen says, as the molecule must have the right disulfide bond linkages to effectively function in the body.

Protein Sleuth
Illustration by Christina Ullman.

One of DESI’s advantages, Chen says, is that it can directly analyze liquid samples without sample preparation. This could give it broader applications than the current technique commonly in use, electrospray ionization, which requires pretreatment of samples. The coupling of MS with EC by DESI (EC/DESI-MS) involves simpler instrumentation than conventional methods. Many biological molecules under study naturally occur in liquid form and are electrolytically active, explains Chen, who collaborates on the work with Ohio University Professor Howard Dewald and graduate student Yun Zhang.

Hao Chen
Hao Chen.

The technique of EC/DESI-MS can be used for a wide range of studies, from small organic molecules to high-mass proteins. Compared to conventional methods, the technique can examine much larger, more complex molecules than ever before, Chen says.

Chen, who is funded by the National Science Foundation, has applied for a patent on the technique, and is looking for additional proteins to test. His goal is to make the EC/DESI-MS technique accessible to other scientists searching for a more efficient, cost-effective way to identify candidates for new drugs.

By Andrea Gibson

This article will appear in the Autumn/Winter 2011 issue of Perspectives magazine, which covers the research, scholarship, and creative activity of Ohio University faculty, staff, and students.

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