mPEG L-Lysine - MW 10000 Da

Cat. No.: m163995

GRADE & PURITY MW 10000 Da

Storage

Room temperature

Shipped In

Normal

Visão geral

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

Especificações e pureza

MW 10000 Da

Condições de armazenamento de armazenamento

Room temperature

Enviado em

Normal

Propriedades químicas e físicas

• Solubilidade: Lyophilized powder form;Soluble in regular aqeous solution and common organic solvents

Application Protocols

No vendor-validated protocols are provided for this specific item. It is not an immunoassay antibody or enzyme standard. For bioconjugation workflows, use general procedures such as:

• NHS-ester coupling in HEPES/PBS (pH 7.5–8.5), avoiding amine-containing buffers.
• EDC/NHS-mediated amide formation in MES buffer, pH 5–6 activation then neutral coupling.
• Reductive amination in acetate buffer with sodium cyanoborohydride.

Exact conditions and recommended dilutions/concentrations are application-dependent and should be optimized empirically. Refer to the literature examples under Reaction Conditions and Synthetic Utility.

Biological Roles

This product is intended for research use only. The following information is provided as general biochemical context.

• L-lysine (literature): an essential, positively charged amino acid at physiological pH; participates in protein structure (salt bridges), enzyme active sites, and post-translational modifications (acetylation, methylation, ubiquitination at ε-amino). Free lysine pKa values are ~9–10 for amine groups, conferring cationic behavior that mediates nucleic acid binding and cellular interactions when presented multivalently.
• PEG segment (literature): poly(ethylene glycol) is widely used as an inert, hydrophilic moiety that reduces protein adsorption and aggregation. Its chain hydration shell yields steric stabilization and decreased immunogenic interactions in surface coatings.
• Combined in mPEG–L-lysine: the conjugate serves as a hydrophilic spacer that can present one or more amines for covalent attachment of biomolecules, dyes, or haptens. The PEG domain enhances aqueous solubility and can mitigate nonspecific interactions in complex biological media, while lysine’s amine(s) enable site-selective derivatization.
• Charge state and binding: protonation of the lysine ε-NH2 under physiological conditions (pH ~7.4) imparts positive charge, which may promote electrostatic association with anionic biomacromolecules; the PEG shell often tempers this interaction to reduce irreversible binding (literature/general).

Note: No clinical or therapeutic claims are made. Performance in any biological system should be validated empirically for the intended research application.

Buffer Applications

mPEG–L-lysine is not itself a buffering reagent. However, its amine functionality and PEG solubility profile inform buffer selection for conjugation and handling.

Practical guidance (literature/general):

• Avoid primary amine-containing buffers (e.g., Tris, glycine) during NHS-ester or isothiocyanate couplings, as they compete with the lysine amines.
• Recommended buffers for amide couplings: 10–100 mM HEPES, PBS, phosphate, or bicarbonate/carbonate at pH 7.5–8.5. Ionic strength (100–200 mM NaCl) can help minimize nonspecific adsorption.
• For carbodiimide (EDC/NHS) chemistry targeting carboxyls: use MES buffer (pH 4.7–6.0) during activation; adjust to pH 7.2–7.5 for amine coupling step.
• Reductive amination: perform in sodium acetate (pH 5.0–6.0) with sodium cyanoborohydride; avoid phosphate at low pH if precipitation occurs.
• Stock solutions: prepare at 1–10 mg/mL in the chosen buffer; sterile-filter (0.22 μm) for cell-adjacent assays.

Compatibility notes:

• Divalent cations (Mg2+, Ca2+) are generally tolerated; transition metals can catalyze PEG oxidation—include 0.1–1 mM EDTA if oxidative discoloration is observed.
• Detergents: nonionic surfactants (Tween-20) are usually compatible but may alter adsorption phenomena on surfaces being modified.

All buffer recipes and pH ranges above are general literature guidance and should be optimized empirically for the specific bioconjugation chemistry.

Green Alternatives

mPEG–L-lysine enables aqueous-phase chemistry and can replace less benign hydrophobic linkers.

Sustainability considerations (literature/general):

• Solvent choice: favor water or aqueous buffers for amide-forming reactions (e.g., EDC/NHS couplings), minimizing organic solvent usage.
• Benign by design: PEG is widely regarded as low-toxicity and non-volatile; lysine is a natural amino acid. Together they lower VOC emissions relative to small hydrophobic spacers.
• Process simplification: water-miscible workups reduce halogenated waste and energy for solvent recovery.

Comparison of linker choices (general):

• mPEG–L-lysine vs hydrophobic alkyl diamines:
  • Solvent: water-compatible vs typically organic-only
  • Biocompatibility: high vs lower
  • Fouling: antifouling surface behavior vs prone to nonspecific adsorption
• mPEG–L-lysine vs PEG–succinamide (single handle):
  • Functional handles: two amines (α and ε) possible vs one
  • Orthogonality: better route planning vs limited diversity

Trade-offs:

• PEG persistence in the environment is higher than that of some biodegradable polypeptides; if biodegradability is critical, consider polypeptide-based spacers (e.g., poly(L-lysine)) or PEG–ester linkages that hydrolyze under defined conditions.
• High-MW PEGs increase solution viscosity—optimize MW to balance performance with processing energy.

Green tips:

• Use catalytic coupling strategies (HOBt-free EDC chemistry, enzymatic ligation where applicable).
• Employ saline/HEPES buffers and avoid tertiary amine buffers that impede carbodiimide chemistry, reducing need for pH corrections and rework.

Pharmaceutical Uses

For research use only. The following describes formulation and manufacturing roles in a non-clinical context (no therapeutic claims).

• Excipient concept (literature/general): PEGylated amino acids like mPEG–L-lysine can function as solubilizing carriers or hydrophilic spacers in investigational conjugates (e.g., PEG–linker–payload constructs) to improve aqueous processability during R&D scale preparation.
• Process aid: the PEG domain reduces aggregation and enhances filtration behavior of conjugates in downstream purification (e.g., tangential flow filtration), facilitating research-scale manufacturability.
• Platform chemistry: lysine provides orthogonal handles (α vs ε amine) enabling site-selective attachment of probes, affinity tags, or cleavable motifs for analytical method development.
• Compendial status: While various PEG grades are listed in pharmacopeias (e.g., USP/NF for PEGs of defined average MW), this specific conjugate’s pharmacopeial status is not established here. Not specified for this item; refer to CoA/Spec Sheet.
• Residuals and quality attributes to monitor in formulation research: average MW and PDI, residual solvents, amine titer, water content, endotoxin/bioburden when used near biological systems.

Scale-up considerations (general):

• Viscosity rises with MW and concentration; select MW to balance syringeability and mixing energy.
• Filterability: PEGylated constructs often pass 0.22 μm membranes readily; pre-wet with water/buffer to minimize adsorption losses.

Any use in regulated products requires independent qualification; this catalog item is supplied strictly for research use only.

Physical Properties

Polymer–amino acid conjugates like mPEG–L-lysine exhibit property distributions rather than single sharp values.

Item-specific values:

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Average molecular weight and PDI: Not specified for this item; refer to CoA/Spec Sheet.
• Density, refractive index, UV cutoff: Not specified for this item; refer to CoA/Spec Sheet.

General/literature characteristics for mPEG–amino acid conjugates:

• Physical state: typically a white to off-white solid, waxy solid, or viscous gum depending on PEG chain length (literature/generic).
• Thermal behavior: polymers lack a discrete boiling point; show a glass transition (Tg) and, for higher MW PEGs, a melting range (Tm) often 50–65 °C for neat PEG backbones around 2–6 kDa (literature, PEG reference). Conjugation and MW shift these ranges.
• Solubility: highly soluble in water and common polar solvents (PBS, saline, acetate/HEPES buffers, MeOH, EtOH), and miscible with DMSO and DMF (literature). Solubility decreases with very high PEG MW in alcohols; poor in nonpolar solvents (hexanes, toluene).
• Hygroscopicity: PEG segments are hygroscopic and readily absorb moisture (literature); handle quickly under dry air to maintain accurate mass.
• pKa: For the lysine ε-NH2 and α-NH2, typical pKa values are ~10.3 and ~9.0; the α-COOH ~2.2 (literature, free lysine). Actual apparent pKa can shift with linkage and microenvironment.
• LogP: PEGylation yields very low logP/“apparent hydrophilicity”; partitioning dominated by PEG–water interactions (literature).

Note: For quantitative specifications and test conditions, consult the product’s CoA/Spec Sheet.

Quality and Grades

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

How to interpret quality for PEG–amino acid conjugates (general guidance):

• Polymer metrics: Average molecular weight (Mn/Mw) and polydispersity index (PDI) are critical. Narrow PDI facilitates reproducible conjugation and material properties.
• Residuals: Trace catalyst, residual solvents (e.g., toluene, DMF), and unreacted small-molecule impurities are often controlled. For analytical applications, low UV-absorbing impurities are preferred.
• Functionality: Verified functional group availability on lysine (e.g., free ε-amine) is key. Vendors may report substitution level (e.g., mmol amine per g) determined by titration or TNBS assays.
• Inorganic content/metals: Not specified for this item; refer to CoA/Spec Sheet if applicable for sensitive applications (e.g., catalysis or bioassays).
• Bioburden/endotoxin: For bioconjugation or cell work, low endotoxin/bioburden can be essential; if required, request supporting data (Not specified for this item; refer to CoA/Spec Sheet).
• Stabilizers: PEG conjugates generally do not need stabilizers; any use of antioxidants or protecting groups should be disclosed (Not specified for this item; refer to CoA/Spec Sheet).

Documentation you should expect:

• CoA reporting average MW, PDI, assay/purity, functional group titer, water content (Karl Fischer) if applicable, and residual solvents. Chromatographic or NMR data may be provided to confirm lysine incorporation and end-group identity.

Reaction and Applications

mPEG–L-lysine serves as a hydrophilic spacer and multifunctional handle in bioconjugation and materials science.

Key application families (literature/general):

• Protein/peptide conjugation: use the lysine amines for selective capture of NHS esters, isothiocyanates, or activated carbonates, creating PEGylated constructs with improved solubility and reduced aggregation.
• Surface modification: graft to carboxylated or activated surfaces (e.g., EDC/NHS-activated carboxylic acids on nanoparticles, films) to yield antifouling, protein-resistant coatings with pendant amines for further functionalization.
• Drug delivery research: attach small molecules via amide/carbamate linkages to the lysine ε-NH2 while using the α-amine or carboxyl (if present) for orthogonal immobilization.
• Crosslinkable hydrogels: react amines with N-hydroxysuccinimidyl esters, aldehydes (Schiff base followed by reductive amination), or epoxides to form networks; gel properties tunable by PEG length and crosslinker density.
• Nanomaterial stabilization: coat metal/oxide nanoparticles, quantum dots, or carbon nanomaterials to impart colloidal stability in physiological buffers.

Practical tips:

• Maintain pH 7.5–8.5 for NHS-ester couplings to balance amine nucleophilicity and hydrolysis rate; use excess base (e.g., 10–50 mM) and buffer lacking primary amines (avoid Tris).
• For aldehyde coupling, perform at pH 5.5–6.5 with sodium cyanoborohydride for reductive amination.
• Quantify available amines by TNBS or fluorescamine assays to calibrate stoichiometry.
• Minimize oxidants; PEG backbones can undergo slow oxidative discoloration—work under inert or low-oxygen conditions for sensitive conjugations.

Reaction Conditions

General literature guidance for common couplings with PEG–lysine constructs (optimize for your system):

• NHS-ester coupling to lysine amines:

  • Solvent: aqueous buffer (HEPES or phosphate) or 1:1 buffer/DMF.
  • pH: 7.5–8.5 (balance amine nucleophilicity vs NHS hydrolysis).
  • Temperature: 20–25 °C; sensitive substrates may be reacted at 4 °C with longer times.
  • Time: 0.5–4 h typical; monitor by amine assays (TNBS/fluorescamine) or LC.
  • Stoichiometry: 1.2–5.0 equiv of NHS-ester per available amine depending on desired substitution.

• EDC/NHS coupling (if carboxyl on the conjugate or target):

  • Activation: MES buffer, pH 4.7–6.0, 10–50 mM EDC with 10–20 mM NHS, 5–30 min.
  • Coupling: adjust to pH 7.2–7.5; 1–2 h at RT.

• Reductive amination (to aldehyde-bearing partners):

  • Buffer: sodium acetate, pH 5.5–6.0; include 10–50 mM NaBH3CN.
  • Temperature: RT; 2–16 h.

• Epoxide opening:

  • Solvent: water/MeOH or water/DMF; base-catalyzed (e.g., Na2CO3, pH 9–10).
  • Temperature: RT–37 °C; 2–8 h.

• Purification: dialysis (MWCO chosen vs polymer MW), spin filtration, or size-exclusion chromatography. Avoid strong anion/cation exchange unless charge states are well controlled.

Notes:

• Avoid Tris/glycine buffers for amine-targeted couplings.
• Degas solutions if oxygen sensitivity is a concern; trace metals can catalyze PEG oxidation—include EDTA if needed.
• Reported yields vary widely (40–90% isolated) due to polydispersity and workup losses (literature/general).

Safety and Handling

Safe handling should follow standard practices for polymers and amino-functional reagents.

• GHS classification, Signal word, Pictograms, H-statements: Not specified for this item; consult the product SDS for authoritative safety information.
• General hazards (literature/generic): low volatility; dusts may cause mechanical irritation to eyes/respiratory tract. Amino functionality may cause mild skin/eye irritation. Not known for peroxide formation.
• Incompatibilities: avoid strong oxidizers (PEG backbone is oxidizable), strong acids/bases during storage, and reactive electrophiles (acyl halides, isocyanates, epoxides) unless intended for derivatization.
• PPE: lab coat, safety glasses, and appropriate chemically resistant gloves (e.g., nitrile). Use a dust mask or work in a fume hood if powders are airborne.
• Handling tips: minimize exposure to ambient moisture (PEG is hygroscopic). For accurate weighing, equilibrate closed container to room temperature to prevent condensation. Use clean, dry spatulas and glassware.
• First aid (overview; defer to SDS):
  • Eye contact: rinse cautiously with water for several minutes; remove contact lenses if present and easy; seek medical attention if irritation persists.
  • Skin contact: wash with soap and water; remove contaminated clothing.
  • Inhalation: move to fresh air; seek attention if symptoms occur.
  • Ingestion: rinse mouth; do not induce vomiting unless directed by medical personnel.
• Waste: dispose of aqueous/organic solutions per institutional and local regulations. PEG-containing aqueous waste is typically non-halogenated; segregate from oxidizers.

Storage conditions: Room temperature (per Product Data). Keep tightly closed, dry, and protected from light to limit oxidative discoloration.

Solvent Selection

mPEG–L-lysine combines a hydrophilic PEG chain with primary amine/carboxyl functionality, favoring polar media.

• Polarity class: highly polar, hydrogen-bonding; behaves as a neutral polymer with cationic character when amines are protonated.
• Preferred solvents (literature/generic):
  • Aqueous buffers (HEPES, PBS, acetate, bicarbonate), especially for bioconjugation.
  • Polar aprotics: DMSO, DMF, NMP for dissolving high-MW materials or conducting coupling reactions.
  • Alcohols: MeOH/EtOH can dissolve shorter-chain PEG conjugates; solubility declines with MW.
• Poor solvents: nonpolar hydrocarbons (hexanes, cyclohexane) and weakly polar aromatics (toluene) generally give low solubility.
• pH considerations: protonation state of lysine strongly affects solubility and reactivity. Keep amines deprotonated (pH 8–9) for nucleophilic coupling; protonate (pH ≤6) to suppress undesired side reactions.
• Salt effects: moderate ionic strength (e.g., 150 mM NaCl) can reduce nonspecific adsorption and aid handling in aqueous media.

Comparison (literature):

• mPEG–L-lysine vs mPEG–NH2: the lysine variant offers an additional amine handle and a defined chiral center, improving orthogonality for dual functionalization.
• mPEG–L-lysine vs mPEG–COOH: lysine provides nucleophilic amines for rapid NHS-ester capture; COOH variants require activation (e.g., EDC/NHS) before coupling.

Practical tip: prepare stock solutions in degassed water or buffer (0.5–10 mg/mL typical) or in dry DMSO for water-incompatible reactions; filter (0.22 μm) for sensitive bioassays to remove particulates.

Storage and Reconstitution

• Storage conditions (item-specific): Room temperature (per Product Data). Store tightly closed in a dry place. Protect from moisture and prolonged exposure to air/light to minimize oxidative discoloration.
• Shipping: Shipped under normal conditions (per Product Data).

Reconstitution (general guidance):

• Solvents: dissolve in ultrapure water, PBS/HEPES buffer, or polar aprotics (DMSO/DMF) depending on downstream chemistry. Start at 1–10 mg/mL.
• Technique: add solvent gradually with gentle vortexing and brief sonication if needed. Filter (0.22 μm) for sensitive biological assays.
• pH control: adjust buffer pH to match intended reaction (e.g., pH 7.5–8.5 for NHS couplings). Avoid amine-containing buffers (e.g., Tris) when targeting lysine amines.

Working solutions:

• Aqueous stocks are best stored refrigerated (2–8 °C) for short term (days) or frozen (–20 °C) for longer term (weeks to months) in aliquots to avoid repeated freeze–thaw. Protect from microbial growth by sterile filtration and, if appropriate, addition of 0.02% sodium azide for non-cell applications.

Specifications not provided in Product Data (assay, water content, functional group titer): Not specified for this item; refer to CoA/Spec Sheet.

Always allow containers to equilibrate to room temperature before opening to prevent condensation on hygroscopic solids.

Structure and Identity

A methoxy polyethylene glycol (mPEG) conjugated to the amino acid L-lysine; a versatile polymer–amino acid hybrid used as a spacer/handle for bioconjugation and materials assembly.

• Item-specific identifiers (CAS, CID, InChIKey, 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 (note: PEG products are typically polydisperse; report as average MW with PDI).

Structural features (general description; literature):

• Backbone: Poly(ethylene glycol) chain bearing a terminal methoxy (–OCH3) cap on one end, conferring non-reactivity/inertness at that terminus.
• Conjugated residue: L-lysine (chiral, L-configuration) featuring an α-amino and an ε-amino side chain on a (CH2)4 aliphatic spacer, plus a carboxylate at the α-position.
• Linkage motif: Common architectures include an amide or carbamate linkage between PEG and the lysine moiety (exact linkage for this item is not specified; consult CoA/Spec Sheet).
• Functional group inventory: ether repeat units (PEG), terminal methoxy, one or two available primary amines on lysine (depending on protection/substitution), and a carboxyl group if retained; stereocenter at the α-carbon of L-lysine.

2D structural description (verbal): a flexible –[CH2–CH2–O]n– chain terminated by –OCH3 on one end; the opposite end tethered via an amide/carbamate to an L-lysine residue bearing an α-CH(NH2)–COOH and a side-chain –(CH2)4–NH2. Exact substitution/protection pattern is product-specific and not provided here.

Synthetic Utility

mPEG–L-lysine is a modular building block merging a water-solubilizing PEG with nucleophilic amine functionality.

Functional group leverage (literature/general):

• Primary amines (ε- and/or α-): nucleophilic substitution on activated esters (NHS, PFP), activated carbonates, sulfonyl chlorides, and aryl fluorides (SNAr under appropriate activation). Enable urea/carbamate formation with isocyanates/carbonyl diimidazole (CDI)-activated alcohols.
• Carboxyl (if present): EDC/NHS coupling to amines on targets; formation of active esters for later use.
• PEG terminus: methoxy end is inert, providing a single reactive locus on the lysine side, valuable for directional coupling.

Named/typical transformations:

• Amide bond formation (EDC/NHS or HATU in aqueous-organic media) to peptides, dyes, or surfaces.
• Reductive amination with aldehyde-bearing biomolecules/polymers (NaBH3CN, pH ~6).
• Epoxide ring opening to introduce secondary/tertiary alcohols bearing PEG tails.
• Isothiocyanate chemistry to form thioureas with pendant isothiocyanate dyes/haptens.

Retrosynthetic value:

• Serves as a hydrophilic spacer that decouples target recognition elements from surfaces, reducing steric hindrance.
• Orthogonality: protecting-group strategies can differentiate α- and ε-amines (e.g., Boc/Fmoc chemistry) when sequential functionalization is needed.

Practical notes:

• Determine amine loading (mmol/g) experimentally to set stoichiometry; polymer polydispersity makes molar calculations sensitive to accurate assay.
• Use mixed aqueous/DMF systems to dissolve hydrophobic reactants while maintaining PEG solvation; control pH to favor desired selectivity.

Target Specificity

Not applicable. This product is a small-molecule/polymer conjugate, not an antibody or targeted biological reagent. No antigen, epitope, clone, isotype, or species reactivity information applies.

Perguntas frequentes

How should this product be stored?

Store at room temperature.

How is this product shipped?

This product ships under standard ambient conditions. No temperature-controlled packaging is required.

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.