spike protein

noun

variants or less commonly spike glycoprotein

plural spike proteins also spike glycoproteins

: a glycoprotein that protrudes from the envelope of some viruses (such as a coronavirus) and facilitates entry of the virion into a host cell by binding to a receptor on the surface of a host cell followed by fusion of the viral and host cell membranes

Like a key in a lock, these spike proteins fuse to receptors on the surface of cells, allowing the virus's genetic code to invade the host cell, take over its machinery and replicate.

—Bruce Lieberman

Their results, published in Science, confirm that the spike protein on the virus that causes COVID-19 is quite similar to that of its close relative, the SARS virus.

—Francis Collins

Using a powerful imaging technique … , researchers from the National Institutes of Health, Weill Cornell Medical College and Yale University School of Medicine observed the motions of key proteins on the surface of HIV called spike proteins.

—Emily Mullin

called also S protein

Examples of spike protein in a Sentence

Recent Examples on the Web

The physician-scientist and biochemist has falsely claimed spike proteins from COVID-19 mRNA vaccines often cause permanent damage to children's vital organs. —Swapna Venugopal Ramaswamy, USA Today, 18 June 2025

Some of the individuals who experienced chronic illness after getting the shots had detectable levels of spike protein more than 700 days after vaccination. —Stephanie Armour | Kff Health News, ABC News, 8 Mar. 2025

Its findings also don't show the spike protein is a health risk or a cause of vaccine injury. —Stephanie Armour | Kff Health News, ABC News, 8 Mar. 2025

Chronic infections, scientists have now observed over and over, create a distinct pattern of mutations: an overabundance of changes in the spike protein (which helps penetrate human cells) but not in the rest of the virus. —Sarah Zhang, The Atlantic, 24 Feb. 2025

Word History

First Known Use

1969, in the meaning defined above

Rhymes for spike protein

• acetylene
• adenosine
• amphetamine
• anthropocene
• antipyrine
• apomorphine
• apoprotein
• aquamarine
• arsphenamine
• azobenzene
• buprenorphine
• chlorobenzene

Medical Definition

spike protein

noun

variants also spike glycoprotein

: a glycoprotein that protrudes from the envelope of some viruses (as a coronavirus) and facilitates entry of the virion into a host cell by binding to a receptor on the surface of a host cell followed by fusion of the viral and host cell membranes

called also S protein