Researchers from Northwestern University and Cornell University have developed a new platform to characterize and optimize sequences to make glycoproteins. The new technique, dubbed GlycoSCORES, uses mass spectrometry and cell-free protein synthesis. The result is much faster research into protein therapies that may defend against antibiotic-resistant supergerms. It would also accelerate research into other new drugs.

The Current, Lengthy Testing Process

Glycosylation involves sugars attaching to proteins. It has a vital role in how proteins form, work in cells and interact with other cells. In fact, about half of all proteins that are expressed in a cell go through this post-translational alteration. In addition, glycosylation has a critical role in biotechnology and the study of diseases.

The current process for understanding and engineering glycosylation, however, can't adequately explore the significant experimental landscapes necessary to anticipate and design precise glycosylation sites that glycosyltransferases modify. Currently, it takes scientists a few weeks to test millions of compounds to determine good starting points for new drug developments. To screen every enzyme-substrate interaction for new drugs, however, it can take months.

The New GlycoSCORES Technique

To hasten this lengthy platform, the researchers created the systematic process GlycoSCORES. They used glycoengineering knowledge from a Cornell University laboratory to effectively and quickly analyze glycosylation. They also used three methods from the laboratories at Northwestern University:

• Protein glycosylation allows researchers to quickly create and assess a large amount of test tube enzymes.
• Cell-free protein synthesis is a method of creating proteins without using a living or intact organism.
• Self-assembled monolayers for matrix-assisted desorption/ionization (SAMDI) mass spectrometry is a rapid, low-cost way to measure biochemical activity on a surface.

The researchers created six N- and O-linked glycosyltransferases from humans and bacteria in vitro. Then, they thoroughly identified their substrate traits with 13,903 distinct reaction conditions and 3,480 distinct peptides. Using GlycoSCORES, they optimized and designed small glycosylation chain patterns.

The authors of the study explained that they attached a different peptide in each of about 1,500 circular sections on a small plate. Then, they applied an enzyme solution across the range so that each peptide tag could be glycosylated. Next, SAMDI mass spectrometry quantified the glycosylation of every peptide after they rinsed the plate.

The Promise of Speedy Drug Development

Through GlcyoSCORES, the researchers say that they can examine thousands of unique peptide tags in a day. Scientists currently assess only a couple hundred of potential tags in a given period. With the new biotech technique, they can examine several thousand in the same time frame. This acceleration is important because 70 percent of protein therapies utilize glycosylation.

GlycoSCORES also gives researchers more detailed data and allows them to identify optimal tags for glycosylation that they can move ahead with in drug development. It lets scientists ask more precise questions than before too. It could be revolutionary in terms of creating glycoproteins with preferred traits.