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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Therefore, a reminder, any reminder of the SARS-CoV-2 spike protein at least every year or so, could keep your immune system more attuned. Bruce Y. Lee, Forbes.com, 14 Sep. 2025 But the document marshals this evidence to support the claim that mRNA vaccines, which are designed to produce spike proteins, cause the same harm – which is not accurate. Deborah Fuller, CNN Money, 10 Sep. 2025 But the document marshals this evidence to support the claim that mRNA vaccines, which are designed to produce spike proteins, cause the same harm – which is not accurate. Deborah Fuller, The Conversation, 3 Sep. 2025 Bhattacharya expressed concern in the article about mRNA vaccines’ ability to direct human cells to produce spike proteins to trigger an immune response. Alejandra O’Connell-Domenech, The Hill, 13 Aug. 2025 See All Example Sentences for spike protein

Word History

First Known Use

1969, in the meaning defined above

Time Traveler
The first known use of spike protein was in 1969

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Cite this Entry

“Spike protein.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/spike%20protein. Accessed 21 Sep. 2025.

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

Last Updated: - Updated example sentences
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