cystine

[ sis-teen, -tin ]

noun

, Biochemistry.

1. a crystalline amino acid, C 6 H 12 O 4 N 2 S 2 , occurring in most proteins, especially the keratins in hair, wool, and horn, and yielding cysteine on reduction.

cystine

/ ˈsɪstiːn; -tɪn /

noun

1. a sulphur-containing amino acid present in proteins: yields two molecules of cysteine on reduction. Formula: HOOCCH(NH 2 )CH 2 SSCH 2 CH(NH 2 )COOH

Word History and Origins

Origin of cystine¹

1835–45; cyst- + -ine ²; so called because found in the bladder

Word History and Origins

Origin of cystine¹

C19: see cysto- (bladder), -ine ²; named from its being discovered in a type of urinary calculus

Example Sentences

This action is due chiefly to its progressive formation of calcium sulphydrate from the cystine group of the softer keratins.

From Project Gutenberg

Ammonia, therefore, dissolves the cystine without entering into chemical union with it.

From Project Gutenberg

Potash also readily dissolves cystine, as do also oxalic acid and the strong mineral acids.

From Project Gutenberg