mPEG Glutamic Acid - MW 5000 Da

Cat. No.: M163991

CALIDAD & PUREZA MW 5000 Da

Storage

Store at -20°C,Argon charged

Shipped In

Ice chest + Ice pads

Especificaciones

Especificaciones y pureza

MW 5000 Da

Condiciones de almacenamiento de almacenamiento

Store at -20°C,Argon charged

Enviado en

Ice chest + Ice pads

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Propiedades químicas y físicas

• Solubilidad: Lyophilized powder form;Soluble in regular aqeous solution and common organic solvents
• Sensibilidad: Moisture sensitive

Application Protocols

No item-specific, validated protocols are provided for this SKU; refer to the CoA/Spec Sheet. The following general, literature-based workflows illustrate typical use cases.

• Protocol A: EDC/NHS coupling of mPEG–glutamic acid to amine-functionalized nanoparticles

  1. Disperse amine-coated nanoparticles in 50 mM MES buffer, pH 5.5.
  2. Add mPEG–glutamic acid (calculate mmol CO2H from lot data or by titration).
  3. Add 1.5 equiv EDC·HCl and 1.5 equiv NHS relative to CO2H. Stir 15–20 min at RT.
  4. Raise pH to 7.8–8.2 with phosphate or HEPES; continue reaction 1–2 h at RT.
  5. Quench with 20 mM ethanolamine for 15 min. Purify by centrifugation/washing or diafiltration.

• Protocol B: Film/surface modification of amine-rich polymer

  1. Swell substrate in 80:20 DMF:H2O containing mPEG–glutamic acid (5–10 mg/mL).
  2. Add EDC/NHS (1.5 equiv each per CO2H). Incubate 1 h at RT.
  3. Rinse thoroughly with DMF, then water; dry under nitrogen.

• Protocol C: Preparation of NHS-activated mPEG–glutamate (pre-activation)

  1. Dissolve mPEG–glutamic acid in dry DMF (0.05–0.1 M). Cool to 0–5 °C.
  2. Add NHS (1.1–1.5 equiv) and DIC (1.1–1.5 equiv). Stir 1 h cold, then 2 h at RT.
  3. Precipitate into cold ether; collect and dry. Store under argon at −20 °C. Use promptly in anhydrous conditions.

All procedures are for research use only; adjust to your system and observe appropriate safety protocols.

Biological Roles

• General context (literature)

  • PEG segment: Poly(ethylene glycol) is widely used as a biologically inert, hydrophilic spacer that reduces nonspecific protein adsorption and can modulate circulation and diffusion of conjugated constructs. It does not possess intrinsic biological activity but influences hydration and steric shielding.
  • Glutamic acid segment: L‑glutamic acid is a proteinogenic amino acid with roles in metabolism (e.g., transamination, TCA anaplerosis) and contributes negative charge through its carboxylate side chain. In conjugates, it provides a chemically addressable acidic handle and may impart net negative charge at neutral pH.

• Implications for research materials (literature)

  • Antifouling and spacing: mPEG domains confer reduced biofouling on sensors and particles; the glutamate can orient or anchor the polymer to amine-bearing biomolecules or surfaces via amide bond formation.
  • Enzyme accessibility: The PEG spacer can alleviate steric hindrance in enzyme–substrate or antibody–antigen interactions when immobilized on surfaces.
  • Charge and solubility: Ionization of the glutamate carboxylate(s) affects colloidal stability and protein interactions; pH control enables tuning of electrostatic behavior.

Note: This product is for research use only and is not intended for diagnostic, therapeutic, or clinical applications.

Buffer Applications

This reagent is not a buffering agent per se. It does not define a useful conjugate acid/base pair over a narrow pH window in the manner of classical buffers (e.g., Tris, HEPES). Therefore, it is not typically used to establish or maintain pH.

• Practical notes for use in buffers (literature)
  • Solubilization: Dissolves readily in common biological buffers (e.g., PBS, MES, carbonate) depending on Mn and ionization state. Filter sterilization (0.22 μm) is commonly feasible.
  • EDC/NHS coupling workflow: Activation of the glutamate carboxyl in aqueous MES (pH 5.0–6.0) followed by coupling at pH 7.5–8.5 (phosphate, HEPES, or carbonate) is standard practice.
  • Ionic strength: Elevated salt (≥150 mM NaCl) can suppress nonspecific adsorption during surface functionalization while maintaining PEG solubility.

If a buffering function is required, select an appropriate dedicated buffer system and use mPEG Glutamic Acid as an additive or conjugation component within that buffered medium.

Green Alternatives

• Solvent and process choices (literature)

  • Prefer water or water–ethanol mixtures for activation/coupling when feasible; MES or phosphate buffers minimize hazardous waste compared with neat DMF or DCM. If organic solvent is required, consider dimethyl carbonate or 2‑MeTHF for certain non-aqueous steps where solubility allows.
  • Replace DCC with water-compatible EDC·HCl to avoid urea precipitates and chlorinated solvent use. HOBt handling can be avoided by using OxymaPure as a safer additive.

• Material comparisons (general)

  • PEG vs. alternatives: Polyglycerol (hyperbranched) and polysarcosine offer similar hydrophilicity with potential biodegradability or distinct fouling profiles; selection depends on end-of-life and performance needs.

• Mini comparison (literature)

  • Water-based EDC/NHS coupling
    • Pros: Minimal solvent hazard, easy waste handling, biocompatible environment.
    • Cons: Competes with hydrolysis; requires pH control and rapid processing.
  • DMF-based DIC coupling
    • Pros: High solubility for many substrates; reduced competitive hydrolysis.
    • Cons: Higher solvent hazard; urea byproducts; workup requires precipitation or dialysis.

• Waste minimization

  • Use stoichiometric excesses judiciously; capture carbodiimide ureas by filtration. Dialysis and ultrafiltration enable solvent recycling in water-rich processes. Pre-plan precipitation steps to reduce large solvent volumes.

Adopt greener options where they meet performance criteria; verify impacts on coupling efficiency and material properties experimentally.

Pharmaceutical Uses

No pharmacopeial status or excipient grade is specified for this item; refer to CoA/Spec Sheet. The following describes general research/formulation roles for similar materials (not medical claims):

• Formulation and materials roles (literature)

  • Surface modification of delivery systems: mPEG segments confer “stealth” hydrophilicity to liposomes, polymeric nanoparticles, and device surfaces, reducing protein adsorption and aggregation in formulation studies.
  • Linker chemistry: The glutamic acid handle allows covalent attachment to amine-containing APIs, peptides, or polymers to modulate solubility, spacing, or release behavior in research prototypes.
  • Hydrogel components: Carboxyl-bearing PEG macromers can be crosslinked with multi-amine counterparts to form amide-bonded networks for depot matrices and in vitro release studies.

• Analytical and manufacturing considerations (literature)

  • Characterization: SEC/GPC for Mn and Đ; NMR to confirm end-group integrity; residual solvent testing to align with ICH Q3C where applicable.
  • Leachables/extractables: For device coatings, evaluate extractables profiles under relevant conditions.

All uses must remain in the research domain. This product is not approved for human or veterinary use.

Physical Properties

• Item-specific values (specifications)

  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • Density, melting point, glass-transition, water content, residual solvents: Not specified for this item; refer to CoA/Spec Sheet.

• General/literature characteristics for mPEG–amino acid conjugates

  • Physical state: Depending on Mn, PEG derivatives range from low-viscosity liquids (low Mn) to waxy/solid materials (higher Mn). mPEG–glutamic acid commonly appears as a white to off‑white solid (literature).
  • Solubility: High solubility in water and polar organic solvents (e.g., DMSO, DMF); miscible with alcohols. Solubility decreases in nonpolar hydrocarbons. Free carboxylate forms show enhanced aqueous solubility at neutral–basic pH (literature).
  • Partitioning: PEGylated materials are hydrophilic, exhibiting low logP and strong hydrogen-bonding capacity (literature).
  • Thermal behavior: PEG shows a melting transition and a glass transition that shift with Mn; decomposition typically occurs well above 200 °C under inert atmosphere, but amino acid linkages can lower thermal stability (literature). Drying under vacuum at ≤40 °C is commonly used to remove moisture without degradation (literature).
  • Hygroscopicity: PEG chains are hygroscopic; materials can adsorb water from air, affecting mass and coupling efficiency (literature).
  • pKa considerations: The glutamic acid carboxyl groups exhibit acidic pKa values (~2–5, depending on microenvironment and substitution; literature), influencing ionization and solubility in buffers.

Note: Use the lot-specific CoA/Spec Sheet for definitive numeric values relevant to your application.

Quality and Grades

• Item-specific quality information

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

• How to interpret quality for PEG conjugates (general guidance)

  • Molecular weight control: PEGs are polydisperse; key metrics include number-average molecular weight (Mn), weight-average molecular weight (Mw), and dispersity (Đ = Mw/Mn). Tighter Đ indicates more uniform performance in surface modification and bioconjugation.
  • Functional end-group integrity: Verify the presence and loading of the glutamic acid moiety and the methoxy cap. NMR (1H/13C), MALDI-TOF/ESI-MS (for lower Mn), and titration can quantify end-group functionality.
  • Residuals and impurities: Important parameters commonly documented on CoAs include residual solvents (e.g., toluene, DMF), catalyst/metal residues (ppm), inorganic salts, and moisture content (Karl Fischer). For bio-oriented use, bioburden/endotoxin levels and protein binding tests may be listed (when applicable). None are specified here for this item; consult the CoA.
  • UV profile: HPLC or SEC traces and UV absorbance can help confirm low aromatic impurity content for analytical applications.
  • Stabilizers: Not specified for this item; refer to CoA/Spec Sheet. Generally, PEGs do not require stabilizers but benefit from inert-atmosphere storage to minimize oxidation.

• Practical note

  • For quantitative conjugations, use lot-specific functionality (mmol of CO2H per g polymer) when provided; this governs stoichiometry with amines in EDC/NHS or carbodiimide chemistry.

Reaction and Applications

• Materials science and surface engineering (literature)

  • Hydrophilic coatings: mPEG–glutamic acid imparts protein-resistant, antifouling character to surfaces; the glutamate carboxyl enables covalent attachment to amine-functional substrates (polymers, silica, oxides) via carbodiimide chemistry.
  • Nanoparticle stabilization: Adsorbed or covalently attached PEG reduces aggregation and provides colloidal stability in physiological saline; the acidic handle allows oriented coupling to amine-coated quantum dots, gold, silica, Fe3O4, or polymeric NPs.
  • Hydrogel formation: Acts as a mono-functional macromer or chain extender with carboxyl functionality participating in amide-bond formation with multi-amine crosslinkers.

• Bioconjugation and ligand spacing (literature)

  • Spacer/linker: PEG length controls hydrodynamic radius and reduces steric hindrance in enzyme assays or biosensors; glutamic acid introduces a negative charge and potential secondary carboxyl for further diversification (e.g., branching via γ/α selectivity).
  • Activation routes: In situ EDC/NHS activation of the carboxyl to NHS ester; pre-activation using DIC/HOBt; CDI activation for anhydride-like intermediates; or conversion to acyl chloride under strictly anhydrous conditions (for non-aqueous coupling).

• Practical tips

  • Drying: Vacuum-dry to low moisture before stoichiometric couplings; water quenches carbodiimide intermediates.
  • Stoichiometry: Base equivalents and amine:CO2H ratios should be calculated on a mmol-per-gram basis using lot-specific functionality (when available).
  • Purification: SEC/dialysis to remove small-molecule reagents; repeated precipitation from DMF into cold diethyl ether/acetone can provide clean material.

All applications are for research use only.

Reaction Conditions

The following conditions are general literature guidance for carboxyl-directed coupling of mPEG–glutamic acid; optimize per substrate and verify with small-scale trials.

• Aqueous EDC/NHS coupling (to primary amines)

  • Solvent: MES buffer (50–100 mM), pH 5.0–6.0, optionally 10–30% v/v DMF to aid solubility.
  • Reagents: 1.1–2.0 equiv EDC·HCl and 1.1–2.0 equiv NHS (relative to carboxyl, using mmol/g loading).
  • Procedure: Activate 10–30 min at RT; adjust pH to 7.5–8.5 and add amine nucleophile. React 1–4 h at RT (or overnight at 4 °C). Quench residual actives with Tris or ethanolamine.
  • Notes: Maintain low temperature for sensitive biomolecules; minimize activation time to reduce hydrolysis.

• Non-aqueous DIC coupling (for water-sensitive substrates)

  • Solvent: Anhydrous DMF or DCM/DMF; 0.01–0.1 M in macromer.
  • Reagents: 1.1–1.5 equiv DIC with 0.5–1.0 equiv Oxyma or HOBt. Add 2–3 equiv tertiary amine base (DIPEA) if needed.
  • Conditions: RT to 40 °C, 2–16 h. Monitor by FTIR (disappearance of acid C=O at ~1710 cm−1) or by ninhydrin on amine partner.

• Purification

  • Dialysis (MWCO chosen vs Mn), ultrafiltration (10–100 kDa cutoff), or precipitation from DMF into cold ether/acetone. Dry under vacuum.

• Expected outcomes

  • Literature yields for PEG–amide couplings are typically high (60–90% isolated) when stoichiometry and water control are optimized. Side reactions include O→N acyl migration (rare) and urea formation from carbodiimides.

Safety and Handling

• Item-specific hazard data

  • GHS Classification / Signal Word / Pictograms / H‑Statements: Not specified for this item; refer to SDS.

• General safety (literature/good practice)

  • Expected hazards: PEG derivatives and amino acids are generally regarded as low acute toxicity; nonetheless, handle as a laboratory chemical. Dusts may cause mechanical eye/respiratory irritation. Avoid ingestion and prolonged skin contact.
  • PPE: Laboratory coat, safety glasses, and appropriate chemical-resistant gloves (e.g., nitrile). Use in a fume hood when weighing, dissolving, or during couplings to minimize exposure to coupling agents/byproducts.
  • Incompatibilities: Strong oxidizers (PEG backbone can undergo oxidation). Avoid strong acids/bases that may catalyze hydrolysis of ester linkages (if present). Carbodiimide byproducts (e.g., ureas) may cause irritation; manage waste accordingly.
  • Thermal/processing cautions: Avoid overheating; thermal degradation may release irritating fumes. When lyophilizing or concentrating, use gentle temperatures and inert gas.
  • First aid overview: Eye/skin contact—rinse with water for 15 minutes; remove contaminated clothing. Inhalation—move to fresh air. Ingestion—rinse mouth. Seek medical attention if symptoms persist. Defer to SDS for authoritative guidance.

• Storage and handling per Product Data

  • Store at −20 °C, argon charged. Keep tightly sealed, dry, and protected from light. Warm to ambient in a desiccator before opening to prevent moisture condensation. Reseal under inert gas promptly after use.
  • Shipped in an ice chest with ice pads to maintain low temperature during transit.

Solvent Selection

This material is a highly polar, hydrogen-bonding polymer conjugate; solvent choice is driven by target application (coating, conjugation, particle stabilization) and by the ionization state of glutamic acid.

• General/literature solvent compatibility

  • Water and buffers: Typically highly soluble, especially when the glutamic acid is deprotonated (neutral–basic pH). Preferred for bioconjugation and surface treatments on hydrophilic substrates.
  • Polar aprotics: DMF, DMSO, NMP dissolve mPEG–glutamic acid well and are common for carbodiimide or uronium salt couplings to amines on surfaces or small molecules.
  • Alcohols: Methanol, ethanol, isopropanol offer intermediate solubility and are useful for cleaning and precipitation steps.
  • Poor solvents: Aliphatic hydrocarbons (hexanes) and many chlorinated solvents show limited solubility; these can be used to precipitate the polymer from DMF/DMSO.

• Selection tips (literature)

  • For EDC/NHS coupling to amines: Use aqueous MES buffer pH 5.0–6.0 for activation, then adjust to pH ~7.5–8.5 for coupling, or conduct in DMF/H2O mixtures for hydrophobic substrates.
  • For surface grafting on nanoparticles: Choose solvent that wets the surface and disperses the particles (e.g., water for metal oxides; DMF for hydrophobic polymers), then exchange into water.
  • For purification: Dialysis (MWCO appropriate to Mn) in water or buffer removes small-molecule reagents; acetone/ether can precipitate the polymer from DMF.

Note: Verify solvent residual limits and compatibility with downstream assays.

Storage and Reconstitution

• Item-specific storage and shipping

  • Storage Conditions: Store at −20 °C, argon charged (per Product Data). Keep container tightly closed in a dry, inert atmosphere. Protect from light.
  • Shipped In: Ice chest with ice pads to maintain low temperature during transit (per Product Data).

• General handling guidance (literature)

  • Opening: Allow vial to equilibrate to room temperature inside a desiccator before opening to avoid condensation. Work quickly and reseal under argon/nitrogen.
  • Moisture/oxygen control: PEG backbones are hygroscopic and can oxidize slowly; minimize headspace oxygen and repeated exposure to ambient humidity.
  • Aliquoting: For repeated use, prepare single-use aliquots to avoid multiple freeze–thaw cycles and moisture uptake.

• Reconstitution suggestions (general)

  • Solvents: Water, buffer (e.g., PBS, MES), or polar aprotics (DMF, DMSO) depending on application. Begin at 5–20 mg/mL and adjust to solubility/viscosity limits.
  • Filtration: Clarify solutions by 0.22 μm filtration when sterility or particulate removal is required.
  • pH considerations: If leveraging the carboxyl group for coupling, control pH carefully (activation typically at pH 5–6; coupling near pH 7.5–8.5). Avoid strong acid/base that may hydrolyze ester linkages (if present).

• Stability and shelf life

  • Not specified for this item; refer to CoA/Spec Sheet. As a general rule, store dried material under inert gas at −20 °C and use solutions promptly or store short-term at 2–8 °C (aqueous) or −20 °C (anhydrous DMF/DMSO) with desiccation.

For authoritative safety and stability information, consult the SDS and lot-specific documentation.

Structure and Identity

A methoxy‑poly(ethylene glycol) (mPEG) chain covalently linked to a glutamic acid residue; a hydrophilic polymer–amino acid conjugate often used as a linker, spacer, or surface modifier.

• Item-specific identifiers

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

• Structural description (general/literature)

  • Backbone: Linear poly(ethylene glycol) repeat units –[CH2–CH2–O]n– with a terminal methoxy cap (–OCH3) on one end (defining “mPEG”).
  • Conjugation motif: The opposite terminus bears a glutamic acid moiety. Depending on synthetic route, the PEG may be attached via an ester or amide linkage to the α‑ or γ‑carboxyl functionality of glutamic acid; the non-involved carboxyl can remain free for downstream coupling (literature).
  • Functional groups: Ether backbone (PEG), terminal methoxy, and amino-acid functionality (carboxylate(s) and possibly a protected or substituted amine, depending on variant; literature).
  • Polymer features: Polydisperse number-average molecular weight (Mn) with a distribution index (Đ) typical of PEGs (literature). Exact n (repeat count) defines Mn and is lot-specific.

• 2D structure in words (general)

  • Left terminus: –OCH3
  • Chain: –(CH2–CH2–O)×n–
  • Linker: –O–C(=O)– or –NH–C(=O)– to a L‑glutamate skeleton
  • Pendant/terminal acidic group: one free –CO2H (if mono-substituted) enabling further conjugation (literature).

Synthetic Utility

• Functional group logic (literature)

  • mPEG terminus: Methoxy cap renders one end nonreactive, ensuring mono-directional chemistry from the glutamic acid side.
  • Glutamic acid functionality: Provides at least one carboxyl group for amide-bond formation to amines on surfaces, polymers, or biomolecules. Depending on linkage orientation (α vs γ), the remaining carboxyl can be free for further elaboration (e.g., forming dendritic or spacer architectures).

• Representative transformations

  • Carbodiimide-mediated coupling: EDC/NHS in water or DIC/EDC in DMF to generate amide bonds with primary amines (peptides, polymers, surface amines).
  • Active ester and acyl fluoride routes: Preforming NHS esters or using TFFH/TCAF (in anhydrous media) where water-sensitive substrates are involved.
  • Click-ready derivatization: Conversion of the free carboxyl to azide/alkyne-bearing linkers (e.g., via amino-PEG linkers) to enable CuAAC or SPAAC workflows.
  • Salt and block-copolymer formation: Neutralization to carboxylates for electrostatic assembly; grafting onto cationic polymers to form amphiphilic PEGylated copolymers.

• Retrosynthetic value

  • Treat as a mono-functional PEG macromer bearing an acidic handle; simplifies synthesis of asymmetric architectures by eliminating bidirectional PEG reactivity. Facilitates controlled spacing and hydrophilicity in conjugates.

Use lot-specific mmol CO2H per gram for stoichiometry; absent that, titration can determine functional loading.

Target Specificity

Not applicable. This product is a polymer–small molecule conjugate, not a biological affinity reagent (e.g., antibody or ligand with defined epitope specificity). No target, isotype, clone, or species reactivity applies.

Preguntas frecuentes

How should this product be stored?

Store at ?20 °C 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.