130633-02-2

Basic information

• Product Name: L-CYSTEINE (3,3-D2)
• Synonyms: L-CYSTEINE (3,3-D2)
• CAS NO: 130633-02-2
• Molecular Formula: C3H5D2NO2S
• Molecular Weight: 123.17
• Mol File: 130633-02-2.mol
• Article Data: 3

Chemical Properties

• Appearance: /
• Solubility: Methanol (Slightly), Water (Slightly)
• CAS DataBase Reference: L-CYSTEINE (3,3-D2)(CAS DataBase Reference)
• NIST Chemistry Reference: L-CYSTEINE (3,3-D2)(130633-02-2)
• EPA Substance Registry System: L-CYSTEINE (3,3-D2)(130633-02-2)

Safety Data

• Hazardous Substances Data: 130633-02-2(Hazardous Substances Data)

Usage

Uses

L-?Cysteine-?3,?3-?d2 is a labeled analog of L-Cysteine (C995000), which is a non-essential amino acid that can be synthesized by the human body under normal physiological conditions if a sufficient quantity of methionine is available. L-Cysteine is commonly used as a precursor in the food and pharmaceutical industries. L-Cysteine is used as a processing aid for baking, as an additive in cigarettes, as well as in the preparation of meat flavours. Acetylcysteine EP Impurity B

Upstream product

• 67-56-1 methanol 
• 352431-53-9 DL-cystine 2, 2′, 3, 3, 3′,3′-D₆ 

Relevant articles and documents

Assigning Peptide Disulfide Linkage Pattern Among Regio-Isomers via Methoxy Addition to Disulfide and Tandem Mass Spectrometry

Pinpointing disulfide linkage pattern is critical in the characterization of proteins and peptides consisting of multiple disulfide bonds. Herein, we report a method based on coupling online disulfide modification and tandem mass spectrometry (MS/MS) to distinguish peptide disulfide regio-isomers. Such a method relies on a new disulfide bond cleavage reaction in solution, involving methanol as a reactant and 254?nm ultraviolet (UV) irradiation. This reaction leads to selective cleavage of a disulfide bond and formation of sulfenic methyl ester (–SOCH3) at one cysteine residue and a thiol (–SH) at the other. Under low energy collision-induced dissociation (CID), cysteine sulfenic methyl ester motif produces a signature methanol loss (–32?Da), allowing its identification from other possible isomeric structures such as S-hydroxylmethyl (–SCH2OH) and methyl sulfoxide (–S(O)-CH3). Since disulfide bond can be selectively cleaved and modified upon methoxy addition, subsequent MS2 CID of the methoxy addition product provides enhanced sequence coverage as demonstrated by the analysis of bovine insulin. More importantly, this reaction does not induce disulfide scrambling, likely due to the fact that radical intermediates are not involved in the process. An approach based on methoxy addition followed by MS3 CID has been developed for assigning disulfide linkage patterns in peptide disulfide regio-isomers. This methodology was successfully applied to characterizing peptide systems having two disulfide bonds and three disulfide linkage isomers: side-by-side, overlapped, and looped-within-a-loop configurations. [Figure not available: see fulltext.].

β-Deuterium Isotope Effects on Firefly Luciferase Bioluminescence

A 5,5-d2-luciferin was prepared to measure isotope effects on reactions of two intermediates in firefly bioluminescence: emission by oxyluciferin and elimination of a putative luciferyl adenylate hydroperoxide to dehydroluciferin. A negligible isotope effect on bioluminescence provides further support for the belief that the emitting species is the keto-phenolate of oxyluciferin and rules out its excited-state tautomerization, one potential contribution to a bioluminescence quantum yield less than unity. A small isotope effect on dehydroluciferin formation supports a single-electron-transfer mechanism for reaction of the luciferyl adenylate enolate with oxygen to form the hydroperoxide or dehydroluciferin. Partitioning between the dioxetanone intermediate (en route to oxyluciferin) and dehydroluciferin is determined, not by the fate of the hydroperoxide, but by that of the radical formed from luciferyl adenylate, and the kinetic isotope effect (KIE) reflects H-atom abstraction by superoxide.