New Technique Enables High-Sensitivity View of Cellular Functions
Researchers have developed an ultrasensitive method for detecting sugar molecules—or glycans—coming from living organisms, a breakthrough that will make possible a more detailed understanding of cellular functions than either genetic or proteomic (the study of proteins) information can provide. The researchers hope the new technique will revolutionize the study of glycans, which has been hampered by an inability to easily detect and identify minute quantities of these molecules.
“The glycome is richer in information than the genome or the proteome. A cancer cell, for example, might have the same genome as a non-cancer cell, but it produces different sugars,” said Robert Linhardt, the Ann and John H. Broadbent Jr. ’59 Senior Constellation Professor of Biocatalysis and Metabolic Engineering at Rensselaer, and an author of the study. “Until now, the stumbling block in glycomics has been rapid and sensitive determination of the glycans present in a biological sample, and up to now we were very limited by how much we could detect. With this technique that we’ve developed, Glyco-qPCR, we can detect a very small number of molecules, and that should accelerate the growth of the field.”
The new technique was published in Angewandte Chemie International. Linhardt and Jonathan Dordick, director of the Center for Biotechnology and Interdisciplinary Studies (CBIS), vice president for research, and the Howard P. Isermann ’42 Professor of Chemical and Biological Engineering, were joined in the research by Seok Joon Kwon, Kyung Bok Lee, Kemal Solakyildirim, Sayaka Masuko, Mellisa Ly, Fuming Zhang, and Lingyn Li.
As the name of the new technique suggests, Glyco-qPCR is built on Polymerase Chain Reaction (PCR), a technique that enabled fast and cost-effective sequencing of genetic information, fueling a rapid expansion in genetics starting in the mid-1980s.
PCR allows researchers to produce mass copies of a particular sequence of DNA, or “amplify” the sequence, turning one precious sample into a nearly limitless supply of a particular sequence. The large sample makes it possible to perform other techniques that determine the identity of the particular sequence.
The team has developed a technique for chemically attaching a specific DNA sequence to a specific sugar molecule. The team has built a catalogue of molecules that can be “tagged,” each with a specific DNA sequence.
Once tagged, the team uses PCR to amplify the DNA tags, allowing them to identify the tags—and therefore the glycans—that are present, and the proportions in which they are present, in a given sample.
“This gives us a new tool to study fundamental biology and chemistry,” Linhardt said. “It allows us a higher resolution view into the functions of a cell than the genome or proteome. With this tool we can go inside a cell, poke around, and understand how to predict the behavior of that cell and ultimately control it.”