Description

(1-Oxyl-2,2,3,5,5-Pentamethyl-3-Pyrroline-3-Methyl) Methanethiosulfonate is a specialized spin-labeling reagent featuring a stable nitroxide radical and a methanethiosulfonate (MTS) functional group. This compound is critical for site-directed spin labeling (SDSL) in electron paramagnetic resonance (EPR) spectroscopy, enabling the study of protein dynamics, structure, and conformational changes. It is primarily utilized by research scientists and biochemists in academic, pharmaceutical, and biotechnology sectors for advanced structural biology applications.

Application

• Site-Directed Spin Labeling (SDSL) for EPR Spectroscopy: Covalently attaches to cysteine residues in proteins to introduce a paramagnetic nitroxide spin probe.
• Protein Structure and Dynamics Analysis: Used to investigate protein folding, conformational changes, oligomerization, and interactions with ligands or other biomolecules.
• Membrane Protein Studies: Essential for probing the structure and dynamics of challenging targets like ion channels and G-protein-coupled receptors (GPCRs) in lipid environments.
• Distance Measurements: Enables precise distance measurements (up to ~60 Å) via pulsed EPR techniques such as DEER (Double Electron-Electron Resonance) or PELDOR.
• Molecular Ruler in Biophysics: Serves as a reliable probe for measuring distances and monitoring motions within biological macromolecules.
• Development of Biosensors: Can be incorporated into engineered proteins to create sensors that report on environmental changes via EPR signal modulation.

Basic Information

Product Name	(1-Oxyl-2,2,3,5,5-Pentamethyl-3-Pyrroline-3-Methyl) Methanethiosulfonate
CAS No.	339072-96-7
Molecular Formula	C12H22N2O3S2
Molecular Weight	306.44 g/mol
Synonyms	MTSL; (1-Oxyl-2,2,5,5-tetramethylpyrroline-3-methyl)methanethiosulfonate; S-(1-Oxyl-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrol-3-yl)methyl methanesulfonothioate; MTSSL; 3-Maleimido-PROXYL MTS; Nitroxide spin label MTS; PROXYL-based methanethiosulfonate spin label; EPR spin labeling reagent
EINECS	Contact for details

Quality Control

Our (1-Oxyl-2,2,3,5,5-Pentamethyl-3-Pyrroline-3-Methyl) Methanethiosulfonate is produced under strict quality protocols to ensure high purity and batch-to-batch consistency, which is paramount for reproducible EPR experiments. Each batch undergoes rigorous analytical testing, including HPLC for purity assessment and EPR spectroscopy to confirm radical integrity and concentration. A comprehensive Certificate of Analysis (COA) detailing identity, purity, and assay is provided with every shipment.

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 minimize oxidation and degradation of the nitroxide radical. The compound is light-sensitive and easily oxidized. Allow the vial to equilibrate to room temperature in a desiccator before opening to prevent moisture condensation.

Specification

Item	Specification
Appearance	Yellow to orange solid or powder
Identification (IR)	Conforms to structure
Purity (HPLC)	≥ 95%
Assay (EPR)	≥ 90% active radical
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.