cysteine

American  

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

noun

Biochemistry.

1. 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

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cysteine British  

/ -ɪn, ˈsɪstɪˌiːn /

noun

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

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cysteine Scientific  

/ sĭs′tə-ēn′ /

1. A nonessential amino acid. Chemical formula: C ₃ H ₇ NO ₂ S.

2. See more at amino acid

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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

They found that a mirror version of cysteine, a sulfur-containing amino acid, can significantly slow the growth of certain tumors while leaving healthy cells largely unaffected.

From Science Daily

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