mPEG Glutathione

Cat. No.: M163992

GRADE & PURITY MW 2000 Da

Vue d’ensemble

Nanocs' amino acid and peptide PEG conjugates were made from the covalent attachment of PEG to various amino acid derivatives. Conjugates were provided in lyophilized powder form.

Specifications

Product Name

mPEG Glutathione

Spécifications et pureté

MW 2000 Da

Type de molécule

Peptide

Stockage et expédition

Concentration

MW 2000 Da

Conditions de stockage de stockage

Protected from light,Store at -20°C,Argon charged

Expédié en

Ice chest + Ice pads

Application Protocols

No application protocols are provided for this SKU in the product data. Only general literature guidance can be offered; users should optimize conditions for their systems.

• Recommended action:
  • Consult the CoA/Spec Sheet to identify which functional groups are free (thiol, amine, carboxylate) and the average PEG MW.
  • Perform small-scale solubility and coupling trials under the relevant conditions (e.g., maleimide–thiol at pH 6.8–7.0; NHS–amine at pH 7.5–8.5), monitoring by suitable analytics (HPLC, GPC, UV, MS where applicable).

For detailed, step-by-step protocols tailored to this exact material, please refer to published literature on PEG–glutathione conjugates or contact your method development team. This product is for research use only.

Biological Roles

This section summarizes general biological roles of the glutathione moiety; no biological activity is claimed for this specific item, which is for research use only.

• Glutathione (GSH) in biology (literature/general):

  • A tripeptide (γ-L-Glu-L-Cys-Gly) that serves as a major intracellular redox buffer. The cysteinyl thiol participates in reversible thiol–disulfide exchange, detoxification, and maintenance of protein thiol status.
  • Involved in enzymatic processes (e.g., glutathione peroxidases and transferases) and conjugation of electrophiles for cellular export.
  • Exists in reduced (GSH) and oxidized (GSSG) forms; the GSH/GSSG ratio is a marker of cellular redox state in research settings.

• PEGylation context (literature/general):

  • Conjugation of GSH to PEG increases aqueous solubility and can reduce nonspecific interactions; the steric bulk may modulate access of enzymes or transporters to the GSH motif, depending on linkage and architecture.

• Caution:

  • The availability of the cysteinyl thiol and other functional groups in this product depends on the specific conjugation chemistry used; this is not specified for the item. No assertions are made about cellular uptake, transport, or activity for this SKU.

Buffer Applications

mPEG Glutathione is not a conventional buffering agent. It may be used as an additive in aqueous media to influence surface interactions or redox environment, but item-specific guidance is not provided.

• If a free thiol is present (not specified for this item), literature practices for glutathione as a reducing additive include:

  • Concentration ranges: 0.5–10 mM GSH in phosphate or HEPES buffers for maintaining reducing conditions in enzyme assays or protein handling (literature/general).
  • pH: near-neutral (pH 7.0–7.5) to preserve thiol functionality and minimize hydrolysis of sensitive linkers.

• Practical notes (general):

  • Avoid buffers containing primary amines (e.g., Tris) when performing NHS-ester couplings; select phosphate or HEPES.
  • Remove dissolved oxygen by sparging with inert gas if thiol oxidation is a concern.

Since the specific functional group availability and buffering capacity of this conjugate are not defined, consult the CoA/Spec Sheet and optimize empirically for your assay.

Green Alternatives

Selection of mPEG Glutathione versus alternatives should balance performance with environmental considerations.

• Greener or alternative materials (literature/general):

  • Unmodified glutathione (GSH): renewable, biodegradable peptide; lacks PEG’s steric stabilization and may have reduced stability on surfaces.
  • Other hydrophilic polymers: polysaccharides (dextran, pullulan), poly(2-oxazoline)s, or zwitterionic polymers can offer fouling resistance with different life-cycle profiles.
  • Shorter PEGs or PEG-free linkers: may reduce persistence, but can compromise solubility and stealth properties.

• Process considerations:

  • Use aqueous buffers at near-neutral pH when feasible; avoid chlorinated solvents.
  • Employ catalytic, high-atom-economy conjugation chemistries (e.g., thiol–Michael additions, enzymatic ligations) under mild conditions.
  • Design for degradability: disulfide or enzymatically cleavable linkers can facilitate end-of-life breakdown in laboratory disposal streams; linkage type for this item is not specified.

• Trade-offs:

  • PEG provides reliable hydrophilicity and low protein adsorption but is petrochemical-derived and non-biodegradable under typical conditions.
  • Biopolymers may be greener but can introduce batch-to-batch variability and different stability/adsorption profiles.

Choose materials based on performance needs, available waste-handling infrastructure, and institutional green-chemistry guidelines.

Pharmaceutical Uses

No pharmacopeial status or excipient grade is provided for this SKU; it is for research use only.

• General formulation roles for PEG–peptide conjugates (literature/general):

  • Solubilizer and steric stabilizer in research formulations, nanoparticles, and surface coatings due to PEG’s hydrophilicity and protein-repellent properties.
  • Potential to modulate surface charge/hydration shells when coating devices or colloids.

• Considerations:

  • Endotoxin/bioburden limits, residual solvents, and heavy metal content are critical for any translational use; these parameters are not specified for this item.
  • PEG average molecular weight and polydispersity strongly influence viscosity, diffusion, and release behavior; not specified here.

• Regulatory note:

  • No medical or clinical claims are made. Not intended for human or veterinary use. For any application beyond basic research, comprehensive qualification and regulatory assessment would be required and are outside the scope of this product.

Physical Properties

Item-specific measured physical properties have not been provided for this SKU.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight (average): Not specified for this item; refer to CoA/Spec Sheet. Note: PEG–conjugates are reported as average MW (Mn/Mw) due to polydispersity (literature/general).
• Solubility (literature/general):
  • Water: typically highly soluble owing to the PEG segment; exact solubility not specified for this item.
  • Aqueous buffers (pH 6–8): generally soluble; ionic strength and pH can influence peptide ionization.
  • Polar organics: often soluble in methanol, ethanol, and DMSO; reduced solubility in nonpolar solvents.
• LogP/logD: not applicable in the classical sense for polydisperse PEGylated peptides; not specified for this item.
• pKa values (glutathione residues, literature/general):
  • Carboxylates typically pKa ~2–4; cysteinyl thiol pKa ~8–9; amine pKa ~8–9 in free peptide. Effective pKa can shift upon PEGylation and depends on linkage; not specified for this item.
• Thermal properties (literature/general):
  • PEG segments exhibit a glass transition; discrete melting points and boiling points are not defined for polymeric conjugates. Specific Tg/Tm not specified for this item.
• Refractive index/density: Not specified for this item; refer to CoA/Spec Sheet.

Always consult the product’s CoA/Spec Sheet for any lot-specific property data relevant to your application.

Quality and Grades

Item-specific grade/purity information has not been provided for this SKU.

• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.

• What grade typically implies (general guidance):

  • Research grade PEG–bioconjugates generally emphasize identity confirmation (NMR, FTIR), peptide content verification (UV/AAA), average molecular weight (GPC/MALS), and low levels of residual reagents/solvents.
  • Higher grades for bioconjugation may include tighter specifications on residual metals, endotoxin/bioburden, and low UV-absorbing impurities (when intended for analytical or sensitive biological assays). These parameters are not specified for this item.

• Stabilization and formulation (general):

  • PEG conjugates are often supplied lyophilized or as dry powders/syrups. Antioxidants or inert gas overlays may be used to minimize oxidation; this item is specified as argon charged.

• Documentation:

  • For lot-specific specifications (e.g., average MW, polydispersity, residual solvents, water content), consult the CoA/Spec Sheet. Do not assume equivalence between lots for polymer-conjugate materials.

Reaction and Applications

Manufacturer-supplied application details are not provided for this SKU; below are literature/general applications of PEG–glutathione constructs. Confirm compatibility with the specific linkage chemistry of this item.

• Surface modification and colloid stabilization (literature/general):

  • PEG imparts steric stabilization and reduces biofouling; glutathione provides multiple functional groups. If a free thiol remains, it can anchor to noble metal surfaces (e.g., Au) via thiol–gold interactions; if the thiol is consumed in the linkage, anchoring may occur through other groups or require additional handles.

• Redox-responsive systems (literature/general):

  • Disulfide-containing linkers between PEG and GSH can be cleaved in reducing environments; use to create stimuli-responsive materials. The presence of any redox-cleavable linker in this product is not specified.

• Bioconjugation and targeting (literature/general):

  • GSH motifs are employed to engage glutathione transporters or to modulate redox microenvironments in in vitro systems; PEGylation enhances solubility and circulation in model systems. No target specificity is claimed for this item.

• Analytical and separation aids (literature/general):

  • PEGylated peptides can be used as calibration or crowding agents and for modifying stationary phases or surfaces to tune hydrophilicity.

• Caution:

  • The availability of functional groups for downstream coupling (amine, carboxylate, thiol) depends entirely on how GSH is linked to mPEG in this product. Review the CoA/Spec Sheet to determine which groups are free.

Reaction Conditions

No item-specific reaction conditions are provided. The following are literature/general conditions relevant to common PEG–peptide conjugations and downstream uses. Verify compatibility with the specific functional groups available in this product.

• Maleimide–thiol coupling (if mPEG-maleimide was used):

  • Buffer: phosphate or HEPES, pH 6.5–7.0 (limits maleimide hydrolysis and favors thiolate formation).
  • Temperature: 4–25°C; typically complete in 0.5–2 h.
  • Additives: degas to minimize oxidation; avoid competing thiols (DTT/βME).

• NHS ester–amine coupling (if mPEG–NHS was used):

  • Buffer: pH 7.5–8.5 (carbonate or phosphate); avoid primary amine buffers.
  • Temperature: 4–25°C; reaction times 0.5–4 h.
  • Quench excess ester with ethanolamine or Tris after coupling (if compatible with downstream use).

• Carbodiimide-mediated coupling (EDC/sulfo-NHS) to carboxylates:

  • Buffer: MES, pH 4.7–6.0 (activation), then couple to amines at pH 7–8.
  • Temperature: 0–25°C; immediate use of O-acylisourea/NHS esters recommended to limit hydrolysis.

• Click ligation (azide–alkyne, CuAAC or SPAAC):

  • Solvent: aqueous or aqueous/organic; pH ~7–8.
  • Catalysis: CuSO4/sodium ascorbate/THPTA (CuAAC) or catalyst-free (SPAAC).

Expected yields are highly system-dependent; polymer polydispersity necessitates characterization by GPC, MALDI/ESI-MS (as feasible), and NMR.

Safety and Handling

Follow good laboratory hygiene and consult the SDS for authoritative safety data.

• GHS classification and hazards (item-specific):

  • Signal word: Not specified for this item; refer to SDS.
  • Hazard statements (H-Statements): Not specified for this item; refer to SDS.
  • Pictograms: Not specified for this item; refer to SDS.

• General handling (literature/general):

  • Avoid generation of dust/aerosols; handle solutions in a chemical fume hood if volatile reagents or acids/bases are present.
  • Prevent moisture ingress and oxidative exposure that could affect sensitive linkages or free thiols (if present). The product is supplied argon charged; maintain an inert atmosphere when possible.

• Storage incompatibilities (literature/general):

  • Strong oxidizers can oxidize cysteinyl thiols and/or sensitive linkers.
  • Strong acids/bases and high temperatures can promote peptide or linker hydrolysis.

• Personal protective equipment:

  • Laboratory coat, safety glasses, and appropriate chemically resistant gloves (e.g., nitrile). Avoid skin/eye contact.

• First-aid overview (general):

  • Eye/skin contact: Rinse with water for several minutes; remove contaminated clothing. Seek medical attention if irritation persists.
  • Inhalation: Move to fresh air; seek medical attention if symptoms occur.
  • Ingestion: Rinse mouth; do not induce vomiting; seek medical advice.

• Fire safety: PEG-containing materials are combustible; use water spray, CO2, dry chemical, or foam as appropriate. Thermal decomposition may generate CO/CO2. Refer to SDS for details.

Solvent Selection

As a PEGylated peptide, mPEG Glutathione generally exhibits excellent aqueous solubility and compatibility with polar organic solvents; item-specific solubility is not specified and should be verified experimentally at the intended concentration.

• Polarity class (general): strongly hydrophilic/nonionic due to PEG, with ionizable groups from the glutathione moiety depending on pH.

• Typical solvent compatibility (literature/general):

  • Water, PBS, and Tris-buffered saline: usually freely soluble; avoid extreme pH that may promote hydrolysis.
  • DMSO: miscible; often used to prepare stock solutions before aqueous dilution.
  • Alcohols (MeOH/EtOH): often soluble, though peptide ionization can influence behavior.
  • Poor solubility expected in nonpolar solvents (e.g., hexanes, toluene).

• Practical selection tips:

  • For bioconjugation or surface modification, choose buffers that do not interfere with the intended chemistry (e.g., avoid primary amines in buffers for NHS ester–amine coupling; use phosphate or HEPES instead).
  • For maleimide–thiol chemistry (if applicable), use pH 6.5–7.0 buffers without competing thiols (avoid DTT/βME) and limit exposure to oxygen.

• Comparison (general):

  • Unmodified glutathione is highly water-soluble but less surface-active; PEGylation improves steric stabilization and reduces nonspecific adsorption, often benefiting nanoparticle or surface coatings.

Verify solvent and buffer suitability with small-scale tests before committing valuable materials.

Storage and Reconstitution

Follow the item-specific storage guidance provided and handle under inert atmosphere to maintain integrity.

• Storage (item-specific):

  • Store at −20°C.
  • Protect from light.
  • Argon charged; maintain an inert gas blanket after opening when feasible.
  • Shipped in an ice chest with ice pads to limit thermal excursions.

• Stability considerations (general):

  • Avoid repeated freeze–thaw cycles; aliquot upon first use.
  • Minimize exposure to moisture and oxygen, especially if free thiol or redox-sensitive linkers may be present (not specified for this item).

• Reconstitution (general guidance; item-specific solvents not provided):

  • Preferred: ultrapure water or compatible buffer (e.g., phosphate or HEPES, pH ~6.8–7.4), based on intended chemistry. Start with 1–10 mg/mL trial solutions and adjust as needed.
  • If higher concentrations are required or solubility is limited, prepare a concentrated DMSO stock and dilute into aqueous media with gentle mixing; verify compatibility with downstream applications.
  • Filter sterilize (0.22 μm) if sterility is required; avoid shear-sensitive processes if the material is high-MW.

• Container/atmosphere:

  • Use clean, dry, low-binding polypropylene or glassware. After reconstitution, purge headspace with argon and store aliquots at −20°C protected from light.

Consult the CoA/Spec Sheet and SDS for any lot-specific instructions.

Structure and Identity

A PEG–peptide conjugate composed of a methoxy-terminated poly(ethylene glycol) (mPEG) covalently linked to the tripeptide glutathione (γ-L-Glu-L-Cys-Gly).

• Item-specific identifiers:

  • SKU: M163992
  • CAS: Not specified for this item; refer to CoA/Spec Sheet.
  • 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.

• Structural features (general/literature description):

  • mPEG is a linear polyether with repeating –CH2–CH2–O– units and a terminal methoxy cap at one end, conferring non-ionic hydrophilicity and low protein adsorption.
  • Glutathione (GSH) contains a γ-glutamyl linkage (Glu–Cys via the γ-carboxyl), a cysteinyl thiol (–SH), and a terminal glycine. It presents multiple functional groups (carboxylates, amine, thiol) in the native peptide.
  • The exact linkage between mPEG and glutathione (e.g., via the cysteine thiol, an amide to the N-terminus, or other chemoselective strategies) is not specified for this item; refer to CoA/Spec Sheet.
  • PEG conjugates are typically polydisperse; reported molecular weights are number-average or weight-average values (literature note). Degree of polymerization and polydispersity index are not specified for this item.

• 2D structure in words (literature/general): a neutral mPEG chain ending in –OCH3 at one terminus and tethered at the other terminus through a linker to the γ-Glu–Cys–Gly tripeptide scaffold; ionizable carboxylate groups may be present depending on pH. Stereochemistry of the peptide is L at each residue (for native GSH).

Synthetic Utility

mPEG Glutathione functions as a hydrophilic, multifunctional conjugate useful in materials and bioconjugation chemistry; specific reactive handle availability depends on the linkage (not specified for this item).

• Functional group landscape (general):

  • PEG terminus: methoxy-capped at one end; the opposite end is linked to glutathione through an unspecified linker.
  • Glutathione residues: native GSH contains a primary amine (N-terminus), carboxylates, and a cysteinyl thiol. Depending on how this product is constructed, some or all of these may be masked or consumed.

• Utility in synthesis (literature/general):

  • Surface grafting: generation of protein-resistant coatings on metals/oxides; potential anchoring via thiols (if available) or via additional coupling chemistries (EDC/NHS on carboxylates, carbodiimide coupling to amines).
  • Spacer/solubilizing tag: PEG increases solubility of hydrophobic motifs and can reduce aggregation in conjugates.
  • Redox handles: if a disulfide or thiol is present, redox-switchable linkages enable triggered cleavage in reducing environments.

• Retrosynthetic perspective:

  • Access often involves coupling an activated mPEG (e.g., NHS ester, maleimide, azide/alkyne for click) to a selected GSH functional group under mild aqueous conditions, followed by purification to remove unreacted PEG/peptide and small-molecule byproducts.

Target Specificity

No target, antigen, clone, isotype, or species reactivity information is applicable to this product. This SKU is a chemical/bioconjugate reagent and not an antibody or affinity reagent. Item-specific target-binding data are not provided.

Foire aux questions

How should this product be stored?

Store at ?20 °C, protected from light, under argon. It is supplied under an argon blanket; reseal under inert gas after each use.

How is this product shipped?

This product ships in an insulated container with ice pads. Unpack on arrival and transfer it to the storage condition stated above.

What documentation is provided?

Available product documentation, including Certificates of Analysis (COA), Safety Data Sheets (SDS), and specification sheets, is shown in the product document area. Document availability and access follow the current site policy.