cysteine

American

[sis-tee-een, -in] / ˈsɪs tiˌin, -ɪn /

noun

Biochemistry.

a crystalline amino acid, C 3 H 7 O 2 NS, a component of nearly all proteins, obtained by the reduction of cystine. Cys; C

cysteine British

/ -ɪn, ˈsɪstɪˌiːn /

noun

a sulphur-containing amino acid, present in proteins, that oxidizes on exposure to air to form cystine. Formula: HSCH 2 CH(NH 2 )COOH

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

cysteine Scientific

/ sĭs′tə-ēn′ /

A nonessential amino acid. Chemical formula: C ₃ H ₇ NO ₂ S.
See more at amino acid

Other Word Forms

cysteinic adjective

Etymology

Origin of cysteine

First recorded in 1880–85; alteration of cystine

Compare meaning

How does cysteine compare to similar and commonly confused words? Explore the most common comparisons:

cysteine vs. cystine

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Their focus was on reducing two specific amino acids in food: methionine and cysteine.

From Science Daily

Further experiments showed that a specific amino acid, cysteine 272 in the cytoplasmic region of PD-L1, is essential for this modification.

From Science Daily

These included the amino acids cysteine and taurine, along with coenzyme M, which plays a key role in metabolism.

From Science Daily

Further experiments revealed that cysteine sets off a chain reaction that activates immune cells known as CD8 T cells.

From Science Daily

In the course of their experiments, the researchers treated cells with an antioxidant drug -- something that reduces ROS -- called N-acetyl cysteine and saw that this partially restored protein mobility.

From Science Daily

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023