Description

(+)-(1-Oxyl-2,2,5,5-Tetramethylpyrrolidin-3-Yl)Methyl Methanethiosulfonate CAS NO 681034-14-0 is a specialized spin-labeling reagent featuring a reactive methanethiosulfonate (MTS) group, enabling site-directed covalent attachment to cysteine residues in proteins and peptides. This compound is critical for advanced structural biology and biophysical research, particularly in Electron Paramagnetic Resonance (EPR) and site-directed spin labeling (SDSL) studies. It is primarily used by research institutions, pharmaceutical R&D departments, and biotechnology companies investigating protein dynamics, conformational changes, and molecular interactions.

Application

• Site-Directed Spin Labeling (SDSL) for Electron Paramagnetic Resonance (EPR) spectroscopy to study protein structure and dynamics.
• Protein Conformational Analysis, enabling the monitoring of structural changes, folding, and unfolding in real-time.
• Membrane Protein Research, where the stable nitroxide radical provides insights into the local environment and mobility within lipid bilayers.
• Distance Measurements via pulsed EPR techniques (e.g., DEER/PELDOR) to determine intra- and intermolecular distances in biomolecules.
• Biophysical Probe Development for investigating ligand binding, protein-protein interactions, and allosteric mechanisms.
• Structural Biology Tool complementing techniques like X-ray crystallography and NMR by providing dynamic information in solution.
• Oxidative Stress & Redox Biology Studies as a stable radical probe in model systems.

Basic Information

Product Name	(+)-(1-Oxyl-2,2,5,5-Tetramethylpyrrolidin-3-Yl)Methyl Methanethiosulfonate
CAS No.	681034-14-0
Molecular Formula	C11H20N2O3S2
Molecular Weight	292.41 g/mol
Synonyms	(+)-MTSL; (1-Oxyl-2,2,5,5-tetramethylpyrrolidin-3-yl)methyl methanethiosulfonate; (3-Maleimidomethyl-PROXYL) Methanethiosulfonate; MTS spin label; S-(2,2,5,5-Tetramethyl-1-oxyl-3-pyrrolidinylmethyl) methanethiosulfonate; MTSSL; PROXYL-based MTS reagent; 3-Maleimidomethyl-PROXYL MTS
EINECS	Contact for details

Quality Control

Our (+)-(1-Oxyl-2,2,5,5-Tetramethylpyrrolidin-3-Yl)Methyl Methanethiosulfonate is manufactured under strict quality protocols to ensure high purity and batch-to-batch consistency, essential for sensitive biophysical applications. Each lot is accompanied by a comprehensive Certificate of Analysis (COA) detailing purity, identity, and stability. Our quality systems support research requiring reliable and reproducible spin-labeling results.

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) in a desiccated environment due to its hygroscopic (moisture-sensitive) nature. Allow the sealed vial to equilibrate to room temperature before opening to minimize moisture uptake.

Specification

Item	Specification
Appearance	Orange to red solid or viscous oil
Identification (IR)	Conforms to structure
Purity (HPLC)	≥ 95%
EPR Signal	Characteristic nitroxide radical triplet
Water Content (KF)	≤ 1.0%
Solubility	Soluble in DMSO, DMF, acetonitrile, ethanol

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