Bis-sulfone-PEG12-NHS Ester - ≥90% , CAS No.2055105-51-4

CAS: 2055105-51-4 Cat. No.: B597109 Formula: C₅₆H₈₀N₂O₂₂S₂ Peso molecolare: 1197.4

GRADE & PURITY ≥90%

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

Application

227,228,229

Panoramica

Bis-sulfone-PEG12-NHS Ester is a bis-alkylating labeling reagent that is selective for the cysteine sulfur atoms from a native disulfide. These reagents undergo bis-alkylation to conjugate both thiols derived from the two cysteine residues of a reduced native disulfide bond such as the interchain disulfide bonds of an antibody. The reaction results in covalent rebridging of the disulfide bond via a three carbon bridge leaving the protein structurally intact. The hydrophilic PEG spacer increases solubility in aqueous media.

Specifications

Specifiche e purezza

≥90%

Condizioni di conservazione di stoccaggio

Store at -20°C

Spedito in

Ice chest + Ice pads

Questo prodotto richiede spedizione a catena fredda. I servizi di terra e altri servizi economici non sono disponibili.

Purezza

≥90%

Nomi e identificatori

Peso molecolare

1197.4

Application Protocols

• Tested application details for this specific SKU are not provided in the Product Data; refer to the CoA/Spec Sheet or SDS for any validated procedures.
• Example general workflow (for guidance only; literature-based)
  • Disulfide re-bridging on proteins: Reduce target disulfides with TCEP (0.5–5 mM, 30 min, pH 7.0), desalt to remove TCEP. Add Bis-sulfone-PEG12-NHS (1.5–3 equiv per disulfide) from anhydrous DMSO stock to pH 7.0 buffer. Incubate 1–2 h at 20–25°C. Desalt. If desired, proceed with NHS–amine coupling at pH 8.0 for 30–60 min. Quench residual NHS with ethanolamine. Purify by SEC.
  • Surface coupling: Activate amine-bearing surface in bicarbonate buffer (pH 8.3), add reagent from dry DMSO stock, incubate 30–60 min, rinse, then introduce thiol-bearing ligand at neutral pH.
• Always optimize conditions for your system and consult the primary literature. These are not validated specifications for this item.

Biological Roles

• This product is a synthetic crosslinking reagent, not a native metabolite. It does not have intrinsic biological roles.
• General biochemistry context (literature)
  • NHS esters and bis-sulfone motifs are widely used tools for covalent modification of biomolecules, enabling controlled attachment of probes, polymers, or payloads to proteins, peptides, and surfaces.
  • PEG12 spacers can mitigate nonspecific interactions and reduce protein aggregation by increasing hydrophilicity and adding conformational flexibility between conjugated partners.
• No endogenous receptors, transporters, or metabolic pathways are associated with this reagent. Any biological interactions arise solely from its designed reactivity toward primary amines and thiols.
• Research Use Note: For research use only (as specified by the catalog).

Buffer Applications

• Not a buffering agent. This reagent does not establish pH or provide buffering capacity.
• Practical buffer guidance for using this crosslinker (general)
  • NHS–amine coupling: Use amine-free buffers such as phosphate, HEPES, or bicarbonate at pH ~7.5–8.5. Avoid Tris, glycine, or other primary amines that compete with the intended target.
  • Bis-sulfone–thiol reactions: Use neutral to slightly acidic buffers (pH ~6.5–7.5) to preserve thiol reactivity and limit competing hydrolysis. Remove excess reducing agents (e.g., desalting after TCEP reduction) prior to coupling.
  • Keep buffer ionic strength moderate (50–150 mM) to maintain protein stability while allowing efficient diffusion. Include 5–20% anhydrous DMSO/DMF only as needed for solubilization.

Green Alternatives

• Greener solvent choices (general guidance)
  • Replace DMF/DMAc where possible with lower-toxicity solvents or aqueous media:
    • Aqueous buffers with minimal DMSO cosolvent (5–20%) can often sustain reactivity while reducing VOC load and exposure.
    • 2-MeTHF or CPME are greener for non-aqueous preparative steps, though solubility of PEGylated reagents may limit their use.
• Comparison of crosslinking chemistries (general)
  • Bis-sulfone vs maleimide: Bis-sulfone disulfide re-bridging affords enhanced stability, potentially reducing the need for excess reagent and repeat processing.
  • NHS ester vs alternatives: SuFEx aryl fluorosulfates or activated carbonates (pNPC) may offer different hydrolysis profiles but can be less biocompatible; enzyme-mediated ligations (sortase, transglutaminase) are aqueous and selective but require protein engineering.
• Mini comparison table (general)
  • Criterion | Bis-sulfone-PEG12-NHS | Maleimide-PEG-NHS | Enzymatic ligation
  • Stability of thiol link | High (re-bridged thioether) | Moderate (exchange-prone) | Very high (amide/isopeptide)
  • Aqueous compatibility | Good with DMSO cosolvent | Good | Excellent (fully aqueous)
  • Selectivity requirements | Needs reduced disulfides | Free thiols required | Specific recognition motifs
• Operational improvements
  • Use minimal organic cosolvent, run at ambient temperature, and avoid excess reagent to reduce waste. Quench and segregate solvent waste streams for easier recovery.
  • Consider solid-supported scavengers to remove excess electrophile, minimizing aqueous workup.

Pharmaceutical Uses

• Item-specific pharmacopeial status: Not specified for this item; refer to CoA/Spec Sheet.
• Context in pharmaceutical development/manufacturing (general, non-clinical)
  • Employed in process development for bioconjugates (e.g., antibody–drug conjugates, PEGylated proteins) where controlled cysteine re-bridging and lysine acylation are required.
  • Useful for preparing analytical conjugate standards, surface-immobilized ligands, or affinity resins by coupling amine-bearing substrates and subsequently attaching thiol-containing biomolecules (or vice versa).
  • PEG12 spacing can reduce aggregation and improve solubility during formulation studies relative to hydrophobic linkers.
• Compliance considerations
  • For any GMP use, require full analytical characterization (identity, purity, residual solvents, elemental impurities), validated stability under storage, and well-defined specifications for functional group content.
  • Extractables/leachables from packaging and trace catalysts/solvents should be controlled per ICH guidance when scaling to manufacturing support roles.
• Disclaimer: No medical or clinical claims are made. This product is provided for research and laboratory use only.

Physical Properties

• Item-specific physicochemical data
  • Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • Melting point, boiling point, density, refractive index: Not specified for this item; refer to CoA/Spec Sheet.
  • UV/Vis characteristics, water content, residual solvents: Not specified for this item; refer to CoA/Spec Sheet.
• General/literature expectations for this class
  • Physical state: Typically a white to off-white solid for PEGylated NHS esters; hygroscopic and moisture-sensitive (NHS hydrolyzes in water).
  • Solubility profile: High solubility in polar aprotic solvents (DMSO, DMF, DMAc). PEG12 confers partial water miscibility; however, the NHS ester is prone to rapid hydrolysis in aqueous buffers. Stock solutions are commonly prepared in anhydrous DMSO/DMF.
  • Stability considerations: NHS esters hydrolyze faster at higher pH and in the presence of moisture; bis-sulfone Michael acceptors are sensitive to strong nucleophiles and high pH. Store cold and dry.
  • Partitioning: PEGylation reduces lipophilicity relative to hydrocarbon linkers, improving dispersibility in mixed aqueous/organic systems (qualitative statement, literature).
• Practical notes
  • Prepare fresh solutions immediately before use. For aqueous applications, dissolve in dry DMSO/DMF, then dilute into buffered media immediately prior to conjugation to limit NHS hydrolysis.
  • Avoid prolonged exposure to basic buffers before reacting with amines to preserve activated ester integrity.

Quality and Grades

• Item-specific grade/purity: Not specified for this item; refer to CoA/Spec Sheet.
• Interpreting grade for this reagent class (general guidance)
  • Bioconjugation-grade NHS esters are typically supplied at high purity with stringent controls on hydrolysis products (free NHS, acid) and residual solvents. Low water content is critical to maintain activated ester integrity.
  • HPLC and 1H/13C NMR are commonly used for identity and purity assessment; LC–MS provides confirmation of molecular mass and checks for oligomer distribution in PEG-containing materials.
• Stabilization and packaging (general)
  • Materials are often packaged under inert atmosphere with desiccants and shipped cold to minimize hydrolysis—consistent with this item’s shipment on ice and storage at −20°C.
  • Single-use aliquots are recommended to avoid repeated freeze–thaw and headspace moisture ingress.
• What to request on the CoA/Spec Sheet for this item
  • Purity method and result (e.g., HPLC area %, NMR integration).
  • Residual solvents and water content (Karl Fischer).
  • Identity confirmation (MS), and if applicable, functional assay for NHS content/reactivity.
  • Storage and retest date under recommended conditions.
• Practical acceptance criteria (general)
  • Clear, single major peak by HPLC with minimal hydrolysis byproducts.
  • LC–MS m/z matching the expected [M+H]+/adducts for the PEG12 distribution if polydispersity applies.

Reaction and Applications

• Core reactivities (general/literature)
  • NHS ester end: Rapid acylation of primary aliphatic amines to form amide linkages. Reaction rate increases with pH (up to ~8.5) but so does hydrolysis; balance is required.
  • Bis-sulfone end: Functions as a Michael acceptor platform enabling addition–elimination–addition with two thiols. This chemistry is widely used for disulfide re-bridging in proteins/antibodies, generating stable thioether linkages across reduced cysteine pairs.
• Bioconjugation workflows (general)
  • Antibody/Protein modification: Reduce targeted disulfides (e.g., with TCEP) to liberate cysteine thiols. React the bis-sulfone motif to form a stable bridge, then use the NHS terminus to couple to amine-bearing payloads/materials—or invert the sequence by first modifying lysines via NHS and subsequently re-bridge cysteines.
  • Peptide stapling or cyclization: Install intramolecular bridges across engineered cysteines to constrain conformation.
  • Material/surface functionalization: NHS reacts with surface amines (e.g., amino-silanized glass, amine-bearing polymers), while the bis-sulfone enables downstream thiol attachment of biomolecules or polymers.
• Advantages over classical linkers (general comparison)
  • Compared to maleimides, bis-sulfone re-bridged linkages are less prone to retro-Michael exchange and thiol exchange in serum-like conditions.
  • PEG12 spacer reduces steric hindrance, improves solubility, and can enhance conjugation to crowded biomolecular surfaces.
• Practical considerations
  • Order of operations matters: Perform the most hydrolysis-sensitive step promptly (NHS in aqueous buffers). Remove excess reducing agent (e.g., TCEP) before bis-sulfone conjugation if it interferes. Monitor progress by LC–MS (proteins) or HPLC (small molecules).
• Applications from catalog
  • Manufacturer text not provided; above represents general use-cases for this reagent class.

Reaction Conditions

• General conditions for NHS–amine coupling (literature guidance)
  • Solvent/buffer: Phosphate, HEPES, or bicarbonate buffer, pH 7.5–8.5; avoid primary amine buffers (e.g., Tris). For hydrophobic partners, use 5–20% anhydrous DMSO/DMF cosolvent.
  • Temperature/time: 20–25°C for 15–120 min typically suffices; colder temperatures slow hydrolysis and can improve selectivity.
  • Stoichiometry: 1.1–5.0 equiv NHS ester per amine, depending on surface accessibility and desired degree of labeling.
  • Quench: Unreacted NHS esters can be quenched with ethanolamine after desired conversion.
• General conditions for bis-sulfone–thiol reactions (literature guidance)
  • Generation of thiols: Reduce disulfides with TCEP or DTT (pH ~7), then remove excess reductant (desalting, spin columns) to prevent side reactions.
  • Coupling: pH 6.5–7.5 in phosphate or HEPES buffer, 20–25°C. Typical reaction times 0.5–4 h. Often proceeds under mild conditions without catalysts.
  • Mechanistic note: First thiol addition activates the bis-sulfone; subsequent elimination and second thiol addition complete the re-bridging to a stable thioether.
• Workup and analysis
  • For proteins: Desalt or size-exclusion chromatography to remove small-molecule reagents; analyze by LC–MS, SDS-PAGE, UV/Vis (DOL), and SEC for aggregation.
  • For small molecules/surfaces: Purify by HPLC or wash steps; confirm by NMR/LC–MS or surface assays (XPS, contact angle).
• Expected outcomes (illustrative)
  • Under optimized conditions, high conversions and selective re-bridging of accessible disulfides are reported in literature, with stable conjugates exhibiting low exchange in serum-mimicking buffers.

Safety and Handling

• Regulatory and GHS information for this specific item
  • Signal word: Not specified for this item; refer to SDS.
  • Hazard statements (H-phrases): Not specified for this item; refer to SDS.
  • GHS classification and pictograms: Not specified for this item; refer to SDS.
• General hazards for functional groups present (general guidance; defer to SDS)
  • NHS esters: Corrosive/irritant potential; can acylate biological nucleophiles. Hydrolyze to generate NHS and the parent acid.
  • Bis-sulfone electrophile: Michael acceptor that can react with thiols; handle to avoid unintended skin contact. Avoid strong bases and nucleophiles that may cause decomposition or uncontrolled reactions.
  • PEG segments: Generally low acute toxicity, but overall hazard is dominated by reactive end groups and solvents.
• PPE and engineering controls
  • Wear lab coat, safety glasses, and appropriate chemically resistant gloves (e.g., nitrile). Use a fume hood when weighing or preparing solutions, especially when using DMSO/DMF, which enhance dermal absorption of solutes.
• Incompatibilities and precautions
  • Avoid moisture and elevated pH to limit NHS hydrolysis. Avoid strong nucleophiles (excess amines, thiols) unless intended for reaction. Keep away from reducing agents during storage.
  • Ethers/PEGs can form peroxides over long storage only when as neat liquids; this solid PEGylated reagent is not typically peroxide-forming, but standard peroxide awareness for ethers applies to solvents used.
• First-aid overview (general)
  • Skin/eye contact: Rinse with water for at least 15 minutes. Remove contaminated clothing. Seek medical attention if irritation persists.
  • Inhalation/ingestion: Move to fresh air. Rinse mouth; do not induce vomiting. Seek medical attention.
• Always consult the item’s SDS for authoritative safety information.

Solvent Selection

• Polarity/compatibility profile (general/literature)
  • Preferred solvents for stock solutions: anhydrous DMSO, DMF, or DMAc due to high solubility of PEGylated linkers and protection against premature hydrolysis.
  • Aqueous use: Dilute the anhydrous stock directly into buffered media immediately before reaction. PEG12 improves compatibility with mixed aqueous systems, but NHS esters hydrolyze in water; minimize pre-incubation time.
  • Poor choices: Protic solvents (methanol, ethanol) can compete in acylation; high-water buffers or high-pH solutions accelerate hydrolysis.
• Buffer considerations (general)
  • For NHS–amine coupling, use phosphate, HEPES, or bicarbonate buffers at pH ~7.5–8.5 without primary amines (avoid Tris, glycine) to prevent competition.
  • For thiol coupling at the bis-sulfone end, mildly buffered aqueous media (pH ~6.5–7.5) or mixed aqueous/organic systems are typical to maintain selectivity for thiol addition.
• Small comparison (general guidance)
  • DMSO vs DMF: DMSO offers broader biocompatibility in small % v/v and lower volatility; DMF can give slightly faster dissolving and lower viscosity. Both require dryness.
  • Acetonitrile: Sometimes useful for analytical work or rapid injections but has lower solubilizing power for long PEG chains.
• Practical tips
  • Pre-dry solvents over molecular sieves. Filter stocks (0.2 µm PTFE) if particulate is observed. Prepare small aliquots to avoid repeated moisture exposure.

Storage and Reconstitution

• Item-specific storage and shipping
  • Storage Conditions: Store at −20°C (as specified in Product Data).
  • Shipped In: Ice chest + ice pads (as specified), minimizing thermal excursions.
• Handling and reconstitution (general good practice)
  • Protect from moisture and light. Equilibrate the unopened container to room temperature before opening to prevent condensation. Reseal promptly under dry inert gas if possible.
  • Prepare stock solutions in anhydrous DMSO or DMF (e.g., 10–50 mM). Use oven-dried glassware and molecular-sieve-dried solvents. Filter if necessary (0.2 µm PTFE).
  • Aliquot stocks into single-use vials/tubes and refreeze at −20°C or below. Avoid repeated freeze–thaw cycles.
  • Aqueous working solutions should be prepared immediately before use; NHS esters hydrolyze in water. Discard after the experiment unless stability has been verified.
• Stability notes
  • Long-term stability and retest period: Not specified for this item; refer to CoA/Spec Sheet.
  • Indicators of degradation: Increased free NHS or the corresponding acid by HPLC, diminished coupling efficiency.
• Research Use Note: For research use only (as specified).

Structure and Identity

• Item-specific identifiers
  • CAS: 2055105-51-4
  • SKU: B597109
  • InChIKey: Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
• Nomenclature and functional design (general/literature description)
  • Bis-sulfone-PEG12-NHS Ester is a heterobifunctional crosslinker featuring three elements:
    • An amine-reactive N-hydroxysuccinimide (NHS) ester for acylation of primary amines (e.g., lysine side chains, N-termini) to form stable amide bonds.
    • A “bis-sulfone” thiol-bridging motif that undergoes conjugate addition with two thiols, enabling disulfide rebridging in proteins/peptides and forming a stable three-carbon thioether linkage.
    • A hydrophilic PEG12 spacer (ca. 12 ethylene glycol units) to enhance aqueous compatibility, reduce aggregation, and provide distance between conjugated partners.
• Structural features (general/literature)
  • Expected functional groups: activated carboxylate (as NHS ester), multiple sulfone groups adjacent to activated alkenes (Michael acceptor), poly(ethylene glycol) chain, terminal leaving group (NHS).
  • 2D description: An NHS-activated carbonate/carboxylate at one terminus connects via a linear, flexible PEG12 chain to a bis-sulfone electrophile at the opposite terminus. No stereogenic centers are typically present; the PEG segment is conformationally flexible.
• Use context
  • Designed for site-selective conjugations where one end couples to amines (NHS) and the other re-bridges or links cysteines (bis-sulfone), useful in protein, antibody, peptide, and material surface modifications.
• Note: Exact atom connectivity and identifiers for this catalog item are not specified above; consult the CoA/Spec Sheet for definitive structure.

Synthetic Utility

• Functional group logic (general)
  • Orthogonal reactivity: One terminus (NHS) selectively acylates primary amines; the opposite bis-sulfone engages two thiols via conjugate additions. The PEG12 chain provides length/flexibility and hydrophilicity.
  • Retrosynthetic value: Serves as a modular linker to bridge amine-bearing and thiol-bearing partners without protecting groups, enabling convergent assembly of complex conjugates.
• Typical transformations (literature)
  • Protein/peptide conjugation: Site-selective disulfide re-bridging to form stable thioether staples, followed by lysine-directed attachment of small molecules, fluorophores, or polymers.
  • Polymer/material modification: Installation of amine-reactive handles on surfaces, then thiol-click attachment of bioactive ligands; or initial thiol grafting to sulfhydryl-rich substrates, reserving NHS for later amination.
  • Sequential/one-pot strategies: With careful pH and timing control, sequential addition can functionalize both reactive ends in a controlled manner, sometimes in a single vessel.
• Advantages
  • Stability of re-bridged linkages often exceeds that of maleimide-based conjugates under physiological conditions.
  • PEG12 reduces non-specific adsorption and can improve the solubility of hydrophobic payloads after conjugation.
• Practical notes
  • Control stoichiometry to limit over-modification (e.g., of lysines). Remove excess reducing agents prior to bis-sulfone engagement. Monitor with LC–MS/HPLC.
  • If orthogonality is critical, perform the faster/hydrolysis-prone NHS step under strictly controlled timing and temperature, then proceed to thiol bridging under near-neutral conditions.

Target Specificity

• No antigen/biological target specificity is defined for this catalog item.
• This product is a chemical crosslinker; it does not possess inherent selectivity for a particular protein beyond its general chemoselectivity toward primary amines (NHS) and thiols/disulfides (bis-sulfone).
• Item-specific target or clone information: Not applicable.