Description

n-Boc-L-Cysteine Methanethiosulfonate is a high-purity, protected cysteine derivative specifically designed for advanced bioconjugation and peptide chemistry. This compound is a critical reagent for introducing stable, site-specific modifications into proteins and peptides via disulfide bond formation or thiol-reactive chemistry. It is essential for researchers and manufacturers in pharmaceutical development, proteomics, and bioconjugate synthesis, where precise and reliable chemical modification is required.

Application

• Site-Directed Protein Labeling: Used as a key reagent for the selective modification of cysteine residues in proteins and antibodies for drug conjugation (ADC development) and diagnostic probe attachment.
• Peptide Synthesis & Modification: Enables the controlled introduction of thiol-reactive groups or protected cysteine moieties during solid-phase peptide synthesis (SPPS).
• Bioconjugate Chemistry: Facilitates the creation of stable disulfide-linked conjugates for applications in targeted drug delivery and biomaterial functionalization.
• Chemical Biology Probes: Serves as a building block for synthesizing activity-based probes and affinity tags to study protein function and interactions.
• Crosslinking Agent: Employed in the development of crosslinked protein structures or protein-polymer hybrids for material science and enzyme stabilization.
• Protecting Group Strategy: The tert-butoxycarbonyl (Boc) group provides orthogonal protection for the cysteine thiol, allowing for sequential deprotection in complex multi-step syntheses.

Basic Information

Product Name	n-Boc-L-Cysteine Methanethiosulfonate
CAS No.	1043867-42-0
Molecular Formula	C9H17NO5S2
Molecular Weight	283.36 g/mol
Synonyms	(R)-2-((tert-Butoxycarbonyl)amino)-3-((methylsulfonyl)thio)propanoic acid; N-(tert-Butoxycarbonyl)-L-cysteine methanethiosulfonate; Boc-Cys(Mts)-OH; Boc-L-Cysteine(Mts); L-Cysteine, N-[(1,1-dimethylethoxy)carbonyl]-, S-(methylsulfonyl)thio ester; S-Methanesulfonylthio-N-Boc-L-cysteine
EINECS	Contact for details

Quality Control

Our n-Boc-L-Cysteine Methanethiosulfonate is manufactured under strict quality control protocols to ensure high chemical purity and batch-to-batch consistency suitable for research and production. Each lot is accompanied by a comprehensive Certificate of Analysis (COA) detailing purity, identity, and impurity profiles. We adhere to cGMP principles where applicable to support our customers in regulated development pipelines.

Storage

Preserve in a tightly closed container, protected from light. Store at -20°C or below under an inert atmosphere (e.g., argon or nitrogen) to prevent oxidation and degradation. Allow the container to reach room temperature in a desiccator before opening to minimize moisture absorption.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (HPLC)	Conforms
Identification (IR)	Conforms to reference spectrum
Assay (HPLC)	≥ 98.0%
Specific Rotation	Contact for details
Water Content (KF)	≤ 0.5%
Heavy Metals	≤ 10 ppm
Residual Solvents (GC)	Complies with ICH guidelines

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.