| cysteine | <amino acid> The only amino acid to contain a thiol (SH) group. In intracellular enzymes the unique reactivity of this group is frequently exploited at the catalytic site. In extracellular proteins found only as _ cystine in disulphide bridges or fatty acylated. (18 Nov 1997) |
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| cysteine aminopeptidase | <enzyme> Catalyses cysteine-peptide to yield cysteine and peptide Registry number: EC 3.4.11.- (26 Jun 1999) |
| cysteine carboxypeptidase | <enzyme> An enzyme which removes the last peptide bond on a protein (the one at the carboxyl end). Its active site contains the sulphur part of the amino acid cysteine. (09 Oct 1997) |
| cysteine conjugate S-oxidase | <enzyme> Converts s-benzyl-l-cysteine to s-benzyl-l-cysteine sulfoxide; uses o2 and NADPH; may be a flavin-containing monooxygenase Registry number: EC 1.13.12- (26 Jun 1999) |
| cysteine conjugate transaminase | <enzyme> Generates thiopyruvates by deamination of cysteine conjugates leaving the r-s-c bond intact Registry number: EC 2.6.1.- Synonym: cysteine-conjugate alpha-ketoglutarate transaminase (26 Jun 1999) |
| cysteine desulfhydrase | <enzyme> A multifunctional pyridoxal phosphate enzyme. In the final step in the biosynthesis of cysteine it catalyses the cleavage of cystathionine to yield cysteine, ammonia, and 2-ketobutyrate. Chemical name: L-Cystathionine cysteine-lyase (deaminating) Registry number: EC 4.4.1.1 (12 Dec 1998) |
| cysteine desulfurase | <enzyme> Pyridoxal phosphate enzyme which catalyses the formation of l-alanine and elemental sulfur from cysteine; required for full activation of the metalloproteins of azotobacter vinelandii nitrogenase Registry number: EC 4.4.1.- Synonym: nifs gene product, azotobacter, nifs protein, azotobacter (26 Jun 1999) |
| cysteine proteinase | <enzyme> An enzyme that destroys proteins by hydrolysis, turning them back into individual amino acids. (09 Oct 1997) |
| cysteine proteinase inhibitors | Exogenous and endogenous compounds which inhibit cysteine proteinases. (12 Dec 1998) |
| cysteine proteinases | <enzyme> Peptide hydrolases which have a cysteine involved in the catalytic process. This group of enzymes is inactivated by sulfhydryl reagents. Registry number: EC 3.4.22 (12 Dec 1998) |
| cysteine S-conjugate N-acetyltransferase | <enzyme> Catalyses n-acetylation of l-cysteine thioesters to form mercapturic acids; important in drug detoxication Registry number: EC 2.3.1.80 Synonym: cscn acetyltransferase (26 Jun 1999) |
| cysteine string protein | <protein> (CSPs) Peripheral membrane proteins that contain more than 10 palmitoylated cysteines and a DNA J homology domain. Nature 375:647 (18 Nov 1997) |
| cysteine sulfinate desulfinase | <enzyme> Catalyses removal of elemental sulfur and selenium atoms from cysteine, cystine, selenocysteine and selenocystine to produce l-alanine. Registry number: EC 4.4.1.- (26 Jun 1999) |
| cysteine sulfinic acid | -O2S-CH2CH (NH3)+COO-;a natural oxidation product of cysteine; an intermediate in the formation of taurine (via cysteic acid). (05 Mar 2000) |
| cysteine synthase | <enzyme> An enzyme that catalyses the biosynthesis of cysteine in microorganisms and plants from o-acetyl-l-serine and hydrogen sulfide. Chemical name: O(3)-Acetyl-L-serine acetate-lyase (adding hydrogen sulfide) Registry number: EC 4.2.99.8 (12 Dec 1998) |
| acetyl CoA-(beta-aminoethyl)-L-cysteine omega-N-acetyltransferase | <enzyme> Forms s-(beta-n-acetyl-aminoethyl)-l-cysteine Registry number: EC 2.3.1.- Synonym: acoac-acetyltransferase, acetyl coenzyme a-(beta-aminoethyl)-l-cysteine omega-n-acetyltransferase (26 Jun 1999) |
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| Carica candamarencis glycosylated cysteine proteinase | <enzyme> A glycoprotein from mountain papaya with the carbohydrate moiety bound to asparagine at position 44; has high degree of identity with chymopapain; amino acid sequence has been determined Registry number: EC 3.4.22.- Synonym: cc-iii cysteine proteinase (26 Jun 1999) |
| glutamate-cysteine ligase | <enzyme> One of the enzymes active in the gamma-glutamyl cycle. It catalyses the synthesis of gamma-glutamylcysteine from glutamate and cysteine in the presence of ATP with the formation of ADP and orthophosphate. Chemical name: L-Glutamate:L-cysteine gamma-ligase (ADP-forming) Registry number: EC 6.3.2.2 (12 Dec 1998) |
| mercaptolactate-cysteine disulfiduria | Elevated levels of the mixed disulfide of 3-mercaptolactate and cysteine in the urine. (05 Mar 2000) |
| methyl cysteine hydrochloride | Mecysteine hydrochloride;the methyl ester of cysteine hydrochloride; a mucolytic agent. (05 Mar 2000) |
| Onchocerca volvulus L3 cysteine protease | <enzyme> Required for molting of o. Volvulus third stage larvae; genbank u71150 Registry number: EC 3.4.22.- Synonym: cysteine protease l3, o volvulus, lovcp (26 Jun 1999) |
| L-cysteine-cystine C-S lyase | <enzyme> C-des - cysteine desulfhydrase; a pyridoxal phosphate- containing enzyme from synechocystis involved information of fe-s cluster of ferredoxin; catalyses the breakdown of l-cysteine to yield sulfide, pyruvate and ammonia; increased activity with cystine, yielding cysteine persulfide as the primary product; mw about 43 kD Registry number: EC 4.4.1.- Synonym: c-des lyase (26 Jun 1999) |