ser·​pin | \ ˈsir-pən How to pronounce serpin (audio) , ˈser- How to pronounce serpin (audio) \

Medical Definition of serpin

: any of a group of structurally related proteins (as antithrombin and antitrypsin) that are typically inhibitors of proteases having serine as the main funtional group and that include some (as ovalbumin and angiotensinogen) which have lost their inhibitory action The identification of an intracellular serpin (protease inhibitor) that prevents necrosis caused by multiple noxious stimuli indicates that necrosis can be regulated, programmed, and driven by a peptidase stress-response pathway. — Richard S. Hotchkiss, M.D. et al., The New England Journal of Medicine, 15 Oct. 2009 Apparently evolution has completely adapted the serpin structure for its new role in these proteins as a transport agent, as there is no evidence of any retained protease inhibitory activity. — Daniel F. Voytas, et al., letter in Nature, 17 Nov. 1988

History and Etymology for serpin

serine proteinase inhibitor

Keep scrolling for more

Comments on serpin

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


a period when something is suspended

Get Word of the Day daily email!

Test Your Vocabulary

Summer 2019 Words of the Day Quiz

  • a-bowl-of-peach-sorbet-with-cut-peaches-next-to-it
  • Which is a synonym of desideratum?
Spell It

Can you spell these 10 commonly misspelled words?

Word Winder's CrossWinder

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!