Long COVID Atlas
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Plain-language first, with specialist detail below. For understanding, not medical advice.

Long COVID Atlas › Glossary › Spike protein

Gene/Protein

Spike protein

https://longcovidatlas.org/glossary/spike-protein

In plain language

What it is

The part of the virus that lets it enter cells. Some of it can linger in the body long after infection.

Why it matters

It can irritate and injure blood vessels on its own, even without live virus present.

Think of it like

A key that fits the lock on your cells, and one that keeps rattling the lock even after the burglar has gone.

Healthy: ACE2 keeps the balance ACE2 converts angiotensin II into the protective, vessel-relaxing form endothelial cell surface ACE2 relaxAng IIbalanced Long COVID: spike occupies ACE2, the balance tips spike protein angiotensin II rises endothelial cell surface the balance tips spike blocks ACE2 → angiotensin II rises → vessels constrict & inflame → endothelial dysfunction
Spike protein docks onto ACE2, the same receptor the virus uses to enter cells. With ACE2 occupied and depleted, the protective arm that relaxes vessels falls and angiotensin II rises, tipping the balance toward constriction and inflammation. That tilt is endothelial dysfunction beginning.

For specialists

Formal definition

The SARS-CoV-2 surface glycoprotein that binds ACE2 to mediate cell entry; its S1 subunit alone can perturb endothelial cells.

Mechanism

Spike binds and depletes endothelial ACE2, shifting the renin-angiotensin balance toward angiotensin II, and triggers inflammatory and pro-coagulant signaling.

Sources

Related terms

ACE2Endothelial dysfunctionViral persistence