UBC researchers publish first close-up look at B.1.1.7. variant

Variant has mutation that enhances virus's ability to bind to and enter human cells but it doesn't offer the virus any more protection against existing vaccines.

Healthing.ca May 3, 2021

UBC researchers have become the first in the world to capture and publish structural images of the spike protein on B.1.1.7., the highly contagious COVID-19 variant first identified in the UK. UBC handout

UBC researchers have become the first in the world to capture and publish structural images of the spike protein on B.1.1.7., the highly contagious COVID-19 variant first identified in the UK.

The B.1.1.7. variant has an unusually large number of mutations but the most interesting to scientists is the N501Y mutation located on the portion of the spike protein that the virus uses to latch on to human cells.

The N501Y mutation is considered a major adaptation and believed responsible for the increased viral transmission of COVID-19.

Dr. Sriram Subramaniam, a professor with UBC’s department of biochemistry and molecular biology, says while the mutation does enhance the virus’s ability to bind to human ACE2 receptors and enter cells, it doesn’t offer the virus any more protection against existing vaccines.

“Our analysis revealed that even though the N501Y mutant can bind and enter our cells more readily, it can still be neutralized by antibodies that block the entry of the unmutated version of the virus into cell,” Subramaniam said in a release. “This is an important observation and adds to the growing body of evidence that the majority of antibodies elicited in our immune system by existing vaccines are likely to remain effective in protecting us against the B1.1.7 variant.”

VOC

SARS-CoV-2, the official name of the virus that causes COVID-19, is 100,000 times smaller than the size of a pinhead.

The pictures of variant and mutation, taken at near-atomic resolution, were captured using a 12-foot-tall cryo-electron microscopes and published in the science journal

PLOS Biology.

“This powerful imaging technology uses beams of electrons to visualize shapes of tissues and cells using ultra-cooling, or “cryo” techniques—essentially, the imaging of samples at liquid nitrogen temperatures,” said Dr. Subramaniam.

B.1.1.7 is one of three variants of concerns (VOC) identified in B.C. along with the P.1 and B.1.351 variants, which were first identified, respectively, in Brazil and South Africa.

According to data released by the B.C. Centre of Disease Control, presumptive VOC made up nearly 78 per cent of all B.C. COVID-19 cases reported between April 18 and 24. The B.1.1.7 variant was found in nearly 60 per cent of the VOC cases, while the P.1 variant was found in around 40 per cent of them.  The B.1.351 variant was found in just a small fraction of cases.

Dr. Subramaniam says his department is studying all variants that have been detected B.C., including the B.1.617 variant of interest that is fueling the COVID-19 crisis in India.

“It’s important to understand the different molecular structures of these emerging variants to determine whether they’ll respond to existing treatments and vaccines and ultimately find ways to control their spread more effectively,” he said.

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