Canadians Peer Inside SARS Coronavirus Proteins

The team of physicists and clinical researchers worked together to examine and characterize two proteins associated with SARS and determine the role they play in the progression of the disease.

The 16-member team published its study Mass Spectrometric Characterization of Proteins from the SARS Virus: A Preliminary Report in the on-line version of the journal Molecular and Cellular Proteomics.

"This team has made a useful contribution in the effort to understand the structure of SARS," says Dr. Ken Standing, professor emeritus in the University of Manitoba department of physics and astronomy, one of the study's co-authors.

Dr. Frank Plummer, scientific director general of the National Microbiology Laboratory (NML) and professor of microbiology at the University of Manitoba, says his team isolated select proteins associated with severe acute respiratory syndrome (SARS) from samples obtained from infected people. They approached researchers at the Manitoba Centre for Proteomics, seeking help in identifying the amino acid sequence of the proteins. Using samples prepared and purified by the NML, the team used the University of Manitoba's time-of-flight mass spectrometry laboratory to analyze the proteins.

The team had already identified the most abundant protein as a coronavirus nucleocapsid prior to the public release of the coronavirus gene sequence, and they subsequently identified the other as a coronavirus spike glycoprotein. The nucleocapsid protein plays an important role inside the virus, and the spike glycoprotein, a pin cushion-like structure, is expected to be the way the virus attached itself to a cell.

The team confirmed 12 sites with sugar attachments on the spike glycoprotein, and identified the sugars attached to four of those sites. Standing said these sites could prove to be a key piece of evidence in explaining how SARS hooks into a cell and may present a target for therapeutic intervention.

"Nature does not do things at random, those sites are there for a purpose," he explained.

The scientific research paper is available online at:http://www.mcponline.org/cgi/reprint/M300048-MCP200v1.pdf

Media note: All the researchers are participating at a conference in Montreal, Canada, this weekend and will be reachable best via e-mail. Dr. Perreault may be the best contact, and reachable at the e-mail address listed above.