cas·​pase | \ ˈka-ˌspās How to pronounce caspase (audio) \

Medical Definition of caspase

: any of several intracellular proteases that have a cysteine residue at their active site, that cleave substrate proteins at specific aspartic acid residues, and that are involved in the initiation and mediation of apoptosis … the mitochondria either rupture or leak, ensuring their own demise and releasing a cocktail of factors that trigger protein-splitting enzymes called caspases. The activated caspases then rapidly cleave proteins in the cell's internal skeleton, membranes, and nucleus to bring about the characteristic hallmarks of apoptosis.— Elizabeth Finkel, Science, 27 Apr. 2001 These genes activate the same pathways involved in cellular suicide, or apoptosis. The cells from the Alzheimer's patients had twice as much of a substance, caspase-3, involved in cellular suicide.— Jamie Talan, The Dallas Morning News, 10 June 2000

Learn More about caspase

Cite this Entry

“Caspase.” Medical Dictionary, Merriam-Webster, Accessed 27 Sep. 2020.

Comments on caspase

What made you want to look up caspase? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Challenging Vocabulary Quiz Returns!

  • stylized drawing of woman pole vaulting across gap to get trophy
  • Which is a synonym of fuliginous?
Spell It

Can you spell these 10 commonly misspelled words?

Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!