London: DNA and protein sequencing have forever transformed science, medicine, and society. But, one major molecule in the biological triumvirate has remained largely uncharted -- carbohydrate biopolymers.
Now, scientists claim to have for the first time made the sequence of a complete complex carbohydrate biopolymer, a surprising discovery which provides the scientific and medical communities with a new view of these vital biomolecules, which play a role in everything from cell structure and development to disease pathology and blood clotting.
"Carbohydrate biopolymers, known as glycosaminoglycans, appear to be really important in how cells interact in higher organisms and could explain evolutionary differences and how development is driven. We also know that carbohydrate chains respond to disease, injury, and changes in the environment.
"In order to understand how and why this all happens, we first need to know their structure. And today, at least for the simplest glycosaminoglycan structure, we can now do this,"
Robert Linhardt of Rensselaer Polytechnic Institute, who led a team, wrote in the `Nature Chemical Biology` journal.
The first glycosaminoglycan sequenced was obtained from bikunin. Bikunin is a proteoglycan, a protein to which a single glycosaminoglycan chain is attached.
Unlike less sophisticated carbohydrate biopolymers, such as starch and cellulose, the proteoglycans are decorated with structurally complex carbohydrates that enable them to perform more sophisticated and defined roles in the body.
According to the scientists, the discovery of the structure of bikuin as the first step on the ladder to the discovery of the structure of more complex proteoglycans.
"The first genome sequences of DNA were on the simplest organisms such as bacteria. Once the technology was developed it ultimately led to the sequencing of the human genome.
"In our efforts to sequence carbohydrate biopolymers we don`t yet know if the defined structure we observe for this simple protoglycan will hold for much more complex proteoglycans," Linhardt said.
He added: "Despite all that is known about glycan formation, our understanding has not yet been deep enough to infer sequence or even determine if sequence occurs. These findings represent a new way of looking at these complex biomolecules as ordered structures."