Description

(1-Oxyl-2,2,5,5-Tetramethyl--Pyrroline-3-Methyl) Methanethiosulfonate CAS NO 81213-52-7 is a spin-labeling reagent featuring a stable nitroxide radical and a methanethiosulfonate (MTS) group, enabling site-directed spin labeling (SDSL) of proteins and other biomolecules. This compound is essential for probing protein structure, dynamics, and conformational changes using techniques like Electron Paramagnetic Resonance (EPR) spectroscopy. It is a critical tool for researchers and developers in structural biology, biophysics, and pharmaceutical discovery, where understanding molecular interactions is paramount.

Application

• Site-Directed Spin Labeling (SDSL) of Proteins: Covalently attaches to cysteine residues via the MTS group to introduce a stable nitroxide spin probe for EPR studies.
• Protein Structure and Dynamics Analysis: Used in Electron Paramagnetic Resonance (EPR) and Double Electron-Electron Resonance (DEER) spectroscopy to measure distances and monitor conformational changes.
• Membrane Protein Studies: Ideal for labeling and investigating the structure and function of challenging membrane-bound proteins.
• Biomolecular Interaction Mapping: Helps elucidate binding sites and interaction mechanisms between proteins, nucleic acids, and small molecules.
• Drug Discovery Research: Employed to study target engagement and ligand-induced conformational shifts in potential drug targets.
• Development of Biosensors: Serves as a key component in creating spin-labeled sensors for detecting specific analytes or environmental changes.

Basic Information

Product Name	(1-Oxyl-2,2,5,5-Tetramethyl--Pyrroline-3-Methyl) Methanethiosulfonate
CAS No.	81213-52-7
Molecular Formula	C11H20N2O3S2
Molecular Weight	292.42 g/mol
Synonyms	MTSSL; (1-Oxyl-2,2,5,5-tetramethylpyrroline-3-methyl) methanethiosulfonate; (1-Oxyl-2,2,5,5-tetramethyl-δ3-pyrroline-3-methyl) methanethiosulfonate; MTS spin label; S-(1-Oxyl-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrol-3-yl)methyl methanesulfonothioate; 3-Maleimido-PROXYL MTS derivative; Nitroxide spin label MTS reagent
EINECS	Contact for details

Quality Control

Our high-purity spin-labeling reagents are manufactured under strict quality control protocols to ensure batch-to-batch consistency and reliability for sensitive research applications. Each lot is characterized using advanced analytical techniques including HPLC, NMR, and EPR spectroscopy to confirm identity, purity, and radical integrity. Certificates of Analysis (COA) detailing all relevant specifications are provided with every shipment.

Storage

Preserve in a tightly closed container, protected from light. Store at -20°C or below under an inert atmosphere for long-term stability. Allow the sealed vial to equilibrate to room temperature before opening to prevent moisture condensation. Keep the container in a dry, well-ventilated place.

Specification

Item	Specification
Appearance	Off-white to pale yellow solid
Identification (IR)	Conforms to structure
Identification (EPR)	Characteristic nitroxide radical signal present
Purity (HPLC)	≥ 95%
Solubility	Soluble in DMSO, DMF, acetonitrile

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