Researchers developed a new molecular tool for the identification of sugar-protein attachments, according to study published on April 2, 2019.
This study was conducted by the researchers at Johns Hopkins Medicine. The new molecular tool is known as EXoO, which decodes where on proteins specific sugars are attached — a possible modification due to disease. The development of the tool and its successful use on human blood, tumors, and immune cells is described in this study.
Some of the proteins made in human cells have sugar molecules attached to them, of which N-glycans and O-glycans are the most common ones. Study related to O-glycans have been difficult, as there were no adequate tools to identify them. Researchers, through this study, showed that EXoO can be used in all types of samples including tissues, body fluids, and cells.
EXoO was developed by combining different reactions and using a process the team had developed for studying other sugar-linked proteins and a bacterial enzyme called OpeRATOR. Initially, the protein samples are digested into smaller pieces, then those pieces are attached to a solid support, which is treated with the enzyme OpeRATOR that releases small pieces of proteins at the O-glycan attachment sites. Furthermore, bits of proteins are analyzed to determine where the sugar is attached.
The research team used EXoO on a well-studied glycol-fetal calf protein, which had six potential O-glycan attachment sites, to establish that the new process works. After running this protein through EXoO, they confirmed all the six known sites and identified a new seventh site. Hui Zhang, senior author of the report said, “We are hopeful that this tool will be useful to researchers and those studying the roles of O-linked glycosylation in normal biology and diseases.”