What does cytolysin mean?
Cytolysin names a substance that causes cytolysis—the rupture or dissolution of a cell, usually by damaging its membrane. In immunology and cell biology, the term most often refers to proteins that make cell membranes permeable, form pores, or otherwise disrupt their integrity; bacterial toxins with this action may also be called cytolysins. The word is chiefly a technical term in medicine, microbiology, and experimental biology rather than a general synonym for any substance that kills cells. A cytotoxin is broader: it may poison a cell through many mechanisms without necessarily lysing it. Researchers commonly discuss cytolysin production, release, or activity, and the precise effect depends on the particular molecule and the target cell. The name combines cyto-, from Greek for “cell,” with lysin, related to lysis, “a loosening.” Understanding the distinction is useful in discussions of immune defense, hemolysis, toxin action, and membrane damage.
nounA substance, especially a protein or toxin, that causes the lysis of cells by disrupting their membranes.
- A substance, especially a protein or bacterial toxin, that causes cells to lyse by disrupting their membranes.
"The bacterium secretes a cytolysin that forms pores in host-cell membranes."
"The bacterium secretes a cytolysin that forms pores in host-cell membranes."
"The study compared the cytolysin activity of the two isolated toxin variants."
The plural is used when discussing multiple cytolysins, distinct molecular species, or separate preparations.
"The screen identified two cytolysins with different target-cell specificities."
Cytolysin is a cell's molecular undoing button: it attacks membrane integrity and can make the cell burst.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does cytolysin come from?
The word was formed in English by combining cyto-, from Greek kytos, meaning “cell,” with lysin, which is related to lysis. The latter comes from Greek lysis, meaning “a loosening,” ultimately associated with lyein, “to loosen.” This formation reflects the word's original sense of a substance that loosens or destroys cells, and it links it to related terms such as cytolysis, cytolytic, and bacteriolysin.
Related word forms
How cytolysin is actually used
This is specialized, formal scientific vocabulary, used chiefly in medicine, microbiology, immunology, and experimental biology.
Easily confused with cytolysin
Cytolysin is the substance that causes cells to lyse, whereas cytolysis is the process by which cells rupture or dissolve.
A cytolysin specifically disrupts cell membranes to cause lysis, while a cytotoxin is any substance toxic to cells and may act through other mechanisms.