Poly(Lys, Tyr) hydrobromide - Lys:Tyr (1:1), mol wt 50,000-150,000 , CAS No.41705-04-8

CAS: 41705-04-8 Cat. No.: P477638

GRADE & PURITY Lys:Tyr (1:1), mol wt 50,000-150,000

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

Specifications

Specifications & Purity

Lys:Tyr (1:1), mol wt 50,000-150,000

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

This product requires cold chain shipping. Ground and other economy services are not available.

Chemical and Physical Properties

• x_flash_point_drop_fahrenheit: Not applicable
• x_flash_point_drop_centigrade: Not applicable

Application Protocols

The following research-oriented procedures are general literature practices for polycationic polypeptides and should be optimized per experiment. They are not item-specific specifications.

• Preparation of stock solutions

  • Weigh polymer quickly to minimize moisture uptake. Dissolve in sterile water or buffer (e.g., PBS) at 1–10 mg/mL. If needed, acidify to pH ~6 with acetate to accelerate dissolution. Filter-sterilize (0.22 µm). Store aliquots at −20°C.

• Surface coating (electrostatic adsorption)

  • Clean substrates (glass/plastic) and, if desired, pre-treat to enhance negative charge (e.g., oxygen plasma for research devices). Immerse in 0.01–0.1% w/v polymer solution for 10–60 min at room temperature. Rinse gently with buffer to remove unbound material. Dry or keep hydrated depending on use.

• Layer-by-layer film assembly

  • Alternate dips/spins between 0.01–0.1% w/v Poly(Lys, Tyr)·HBr and a polyanion (e.g., alginate, PSS, hyaluronate) in matching ionic strength buffer (10–150 mM salt), 5–10 min per layer, with buffer rinses between steps.

• NHS ester dye/probe labeling

  • Adjust polymer solution to pH 7.8–8.2 (HEPES). Add NHS reagent (5–20 mol per amine equivalent estimate) in DMSO stock dropwise with stirring. React 1–2 h at RT, protect from light. Quench residual NHS with Tris or ethanolamine. Purify by dialysis or size-exclusion.

• Nucleic acid complexation (research)

  • Mix polymer and DNA/RNA in low-salt buffer at defined N/P ratios (optimize empirically). Incubate 15–30 min before use. Verify complex size/charge by DLS/zeta potential.

Ensure sterility and endotoxin levels appropriate for your assay. Dispose of solutions per institutional guidelines.

Biological Roles

This product is a synthetic polypeptide for research use; it does not have intrinsic biological “function” in organisms. Nonetheless, its constituent residues confer behaviors relevant to biochemical systems (literature/general):

• Electrostatic interactions

  • Protonated lysine side chains bind to negatively charged biomolecules (e.g., nucleic acids, glycosaminoglycans) and surfaces via Coulombic attraction, enabling adsorption and complexation.

• Aromatic/phenolic chemistry

  • Tyrosine residues present phenolic groups capable of hydrogen bonding, π–π interactions, and oxidative coupling (e.g., dityrosine formation) under appropriate conditions.

• Protein-mimetic features

  • The peptide backbone and chiral L-residues provide a biomimetic scaffold that can influence secondary structure and interactions with proteins or membranes, depending on chain length and environment.

• Spectroscopic utility

  • Tyrosine absorbance and intrinsic fluorescence (weak, near 303 nm emission when excited ~275 nm; literature) can assist in qualitative monitoring of adsorption or conjugation events, with the caveat that polymer composition affects signal.

Note: Any biological observations are context-dependent and should be validated within the specific experimental system. This product is for research use only and is not intended for use in humans or animals.

Buffer Applications

Poly(Lys, Tyr) hydrobromide is not a buffer component in the conventional Henderson–Hasselbalch sense. It lacks a well-defined pKa pair for precision buffering and is not typically used to maintain solution pH.

• Practical guidance
  • Use standard biological buffers (e.g., phosphate, HEPES, MES, acetate) to control pH while dissolving or formulating this polymer.
  • Inclusion of low ionic strength acid (e.g., 1–10 mM HCl or acetate) can aid dissolution by maintaining amine protonation without significantly impacting buffer capacity.
  • Avoid strong base buffers that drive deprotonation of amines/phenols and can reduce solubility or promote side reactions.

For applications, refer to Solvent Selection and Application Protocols for dissolution and formulation suggestions.

Green Alternatives

From a green chemistry perspective, Poly(Lys, Tyr) hydrobromide is amenable to aqueous processing, which can reduce reliance on harmful organic solvents.

• Greener processing choices (general)

  • Use water or mild aqueous buffers as the primary solvent for dissolution, coating, self-assembly, and conjugation.
  • Favor carbodiimide (EDC/NHS) coupling in water over organic-phase activation when possible.
  • Employ enzymatic crosslinking (e.g., peroxidase-mediated dityrosine formation) as a milder alternative to chemical oxidants, acknowledging the need to control byproducts.

• Comparison of options (general)

  • Poly(Lys, Tyr)·HBr vs organic-soluble polymers: enables water-based fabrication of films and conjugates, reducing VOC emissions.
  • Alternative polycations
    • Polyethylenimine (PEI): efficient nucleic acid complexation but can be more cytotoxic; often requires buffering and careful waste handling.
    • Poly(L-lysine) (PLL): simpler composition; fewer conjugation handles versus Tyr-containing copolymer; both are readily processed in water.

• Tradeoffs

  • Aqueous systems may necessitate buffers/salts that increase wastewater ionic load; ensure appropriate waste segregation and treatment.
  • Enzymatic or photo-crosslinking strategies can minimize harsh reagents but may introduce specialized catalysts or light sources.

• Practical tip

  • Design workflows to avoid halogenated solvents; if HFIP/TFA are used for specialized processing, recover and neutralize waste and switch back to aqueous media promptly.

Pharmaceutical Uses

This product is supplied strictly for research use only. It is not formulated to any pharmacopeial standard and is not intended for therapeutic or diagnostic applications.

• Research formulation roles (general/literature)

  • Coating of labware or device prototypes to enhance adsorption/immobilization of biomolecules during analytical method development.
  • Component of experimental polyelectrolyte complexes or hydrogels assembled in aqueous media for materials research.
  • Research-only complexation agent for nucleic acids in nonclinical studies.

• Regulatory note

  • No USP/EP/JP monograph applicability is stated. Endotoxin, sterility, and residual solvent specifications suitable for clinical use are not provided.

• Documentation

  • For any work that requires defined quality attributes (endotoxin, bioburden, residuals), request and review the lot-specific CoA/Spec Sheet. Otherwise, standard laboratory research-grade handling applies.

Physical Properties

Item-specific physicochemical specifications (e.g., exact average molecular weight, degree of polymerization, dispersity, water content) are not provided for this catalog entry and may vary by lot.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight (Mn/Mw): Not specified for this item; refer to CoA/Spec Sheet. (Polymeric; typically reported as an average range in kDa in literature.)
• Solubility (general/literature behavior)
  • Water: generally soluble as the hydrobromide due to protonated lysine ε-amines; solubility increases at lower pH.
  • Aqueous buffers: soluble in common biological buffers (e.g., phosphate, HEPES) when pH ≤ ~8; avoid high pH that deprotonates amines and phenols.
  • Organic solvents: limited solubility in most nonpolar/aprotic solvents; may swell or be partially soluble in HFIP or TFA-containing mixtures (literature).
• pKa values (literature, monomeric residues)
  • Lysine ε-NH3+: ~10.3–10.7
  • Tyrosine phenolic OH: ~10.0
  • Note: Apparent pKa can shift in polymers.
• LogP: Not applicable to polymers; behavior is dominated by charge and hydrogen bonding.
• Melting point / glass transition: Not typically defined for polypeptide salts; may show broad thermal transitions (literature). Not specified for this item; refer to CoA/Spec Sheet.
• Density, refractive index: Not specified for this item; refer to CoA/Spec Sheet.
• UV-vis (literature)
  • Tyr aromatic absorbance near 275 nm; useful for qualitative concentration estimates using empirical ε values adjusted for composition and MW.

Quality and Grades

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

• What to look for with polymeric polypeptides (general guidance)

  • Average molecular weight and dispersity (Đ): influences viscosity, film/coating formation, and biological interactions.
  • Composition: molar ratio of Lys:Tyr directly affects charge density and aromatic/phenolic content; verify by supplier data (e.g., elemental analysis, amino acid analysis, NMR, or UV metrics).
  • Counterion identity and residual salts: this product is a hydrobromide; check for residual inorganic bromide content if it impacts your assay.
  • Endotoxin/bioburden: for sensitive biological assays, request low endotoxin lots where applicable.
  • Residual solvents/moisture: moisture uptake can be significant for polycations; confirm by KF/LOD if critical.

• Implications of the hydrobromide form (general)

  • Enhanced aqueous solubility from protonated ε-amines; solution pH may be slightly acidic depending on concentration.
  • Bromide does not absorb strongly in the UV-vis region used for tyrosine monitoring, but high ionic strength may affect certain assays.

• Documentation

  • CoA/Spec Sheet typically provides average MW, composition, and quality metrics. For this item, specific values are not listed above; please consult the lot-specific CoA for experimental planning.

Reaction and Applications

This copolypeptide combines a high density of primary amines (lysine) with phenolic aromatics (tyrosine), enabling diverse conjugation and materials applications.

• Applications (general/literature)

  • Surface coatings: electrostatic adsorption to negatively charged substrates (e.g., glass, tissue-culture plastics pretreated for negative surface charge) to enhance biomolecule immobilization.
  • Layer-by-layer (LbL) films: alternation with polyanions (e.g., alginate, hyaluronate, PSS) to build polyelectrolyte multilayers.
  • Bioconjugation scaffold: multiple amines for NHS ester coupling; tyrosine phenols for diazo coupling, enzymatic crosslinking (e.g., HRP/H2O2), or halogenation/photochemistry.
  • Nucleic acid complexation (research): polycationic complex formation with DNA/RNA for nonviral transfection studies; composition modulates charge density and aromatic interactions.

• Practical notes

  • Dissolution: hydrate in water or buffer at pH 5.5–7.4; gentle stirring; avoid vigorous vortexing that can introduce bubbles and shear.
  • pH control: for NHS ester chemistry, use pH 7.4–8.3 buffers; for EDC/NHS on carboxyl surfaces, activate at acidic pH then couple near neutral pH.
  • Oxidation sensitivity: tyrosine can oxidize; minimize exposure to strong oxidants and intense UV; include antioxidants if compatible.
  • Quantitation: exploit tyrosine absorbance (~275 nm, literature) combined with amino acid analysis or ninhydrin assays to estimate concentration/composition.

• Related named methodologies

  • EDC/NHS carbodiimide coupling, Schiff base/reductive amination (after aldehyde introduction), diazonium coupling to tyrosine, and LbL assembly per Decher’s method (literature).

Reaction Conditions

Typical conditions below are general literature guidance for reactions on poly(Lys, Tyr) backbones; optimize for your specific lot and application. These are not product specifications.

• Amine-targeted conjugation (NHS ester)

  • Solvent: aqueous PBS or HEPES, pH 7.4–8.3
  • Temperature: 4–25°C
  • Time: 0.5–4 h
  • Molar excess: 2–20× of NHS ester per available amine, depending on desired substitution
  • Notes: minimize hydrolysis by adding NHS reagent in portions; maintain mild ionic strength.

• Carbodiimide coupling (EDC/NHS) to carboxyl surfaces

  • Activation: pH 4.5–6.0 (MES buffer)
  • Coupling: pH 7.0–7.4
  • Temperature: ambient
  • Notes: remove excess EDC/NHS thoroughly to avoid crosslinking in bulk solution.

• Reductive amination (after aldehyde introduction)

  • Buffer: sodium phosphate, pH 6.0–7.0
  • Reductant: sodium cyanoborohydride or picoline borane (aqueous-compatible)
  • Time/Temp: 2–16 h, 4–25°C

• Tyrosine diazo coupling (aryl diazonium salts)

  • Solvent: aqueous buffer, pH 8.5–9.5 (to form phenolate)
  • Temperature: 0–10°C for diazonium generation; couple at 0–25°C
  • Caution: control stoichiometry to avoid over-modification; manage azo byproduct safety.

• Enzymatic dityrosine crosslinking

  • Reagents: horseradish peroxidase + H2O2 (µM–mM)
  • Buffer: pH 6–7.4
  • Outcome: gelation/crosslinking; monitor rheology/UV changes.

All conditions should be validated empirically with appropriate controls; monitor substitution by UV, NMR (if feasible), or colorimetric assays.

Safety and Handling

• GHS classification (item-specific)

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

• General laboratory precautions (good practice)

  • Handle as a research reagent; avoid inhalation of powders and contact with eyes/skin.
  • Use appropriate PPE: lab coat, safety glasses, and nitrile gloves; wear a dust mask/respirator if aerosolization of powder is possible.
  • Work in a clean, dry environment; prepare solutions with sterile, filtered water/buffer if sterility is required for your application.

• Incompatibilities and stability (general)

  • Avoid strong oxidizing agents that can modify tyrosine phenols (e.g., peroxides, hypochlorite) and degrade the peptide backbone.
  • Avoid prolonged exposure to strong bases (risk of backbone hydrolysis and phenolate-mediated side reactions) and to elevated temperatures.
  • Light/air: Tyrosine residues can undergo photo-oxidation; minimize exposure to intense UV and store protected from light when in solution.

• First-aid overview (non-authoritative; consult SDS)

  • Inhalation: move to fresh air; seek medical attention if symptoms persist.
  • Skin/eye contact: rinse with water for several minutes; remove contaminated clothing; seek medical attention if irritation persists.
  • Ingestion: rinse mouth; do not induce vomiting; seek medical advice.

Always defer to the product-specific SDS for authoritative hazard and response information.

Solvent Selection

Poly(Lys, Tyr) hydrobromide is a water-compatible polycationic polypeptide; solvent choice is driven by intended application and the need to preserve charge and integrity.

• Polarity and miscibility (general/literature)

  • Polar protic media: water and common biological buffers are preferred; maintain pH below ~8 to keep lysine amines protonated and maximize solubility.
  • Aprotic/organic media: generally insoluble; partial solubility in strong hydrogen-bonding solvents such as HFIP or TFA-containing mixtures can occur for processing/coating, but may modify the polymer.

• Practical choices

  • Aqueous buffers: PBS, HEPES, acetate, or MES at ionic strengths suitable for your assay; filter-sterilize (0.22 µm) after dissolution if sterility is required.
  • Acidified water (e.g., 1–10 mM HCl or acetate) can facilitate rapid dissolution at higher concentrations.
  • Avoid strong base and high-pH carbonate buffers that deprotonate phenols/amines, potentially reducing solubility and promoting side reactions.

• Comparison (general)

  • Poly(Lys)·HBr: higher charge density; greater solubility across pH but lacks phenolic functionality.
  • Poly(Lys, Tyr)·HBr: retains cationic behavior with added phenolic/aromatic character, useful for conjugation or redox/photochemical strategies.

• When to choose

  • Select aqueous media for coatings, electrostatic assemblies, and bioconjugation.
  • Consider volatile acid systems (e.g., TFA/H2O) only for specialized processing, followed by thorough removal to restore neutral/physiological conditions.

Storage and Reconstitution

• Storage conditions (item-specific)

  • Store at −20°C (per Product Data). Keep container tightly closed. Protect from moisture and light. Shipped in an ice chest with ice pads.

• Handling

  • Allow the container to equilibrate to room temperature in a desiccator before opening to minimize moisture condensation.
  • Reseal promptly after use. Consider storing under dry inert gas if repeatedly accessed.

• Reconstitution (general guidance)

  • Solvent: sterile water or appropriate buffer (e.g., PBS, acetate, HEPES). Begin at pH 5.5–7.0 to facilitate dissolution, then adjust to working pH as needed.
  • Concentration: common working stocks are 1–10 mg/mL; higher concentrations may be viscous—stir gently until fully dissolved.
  • Sterilization: filter through 0.22 µm if sterility is required; avoid heat sterilization.

• Aliquoting and stability

  • Prepare single-use aliquots to avoid repeated freeze–thaw. Store frozen at −20°C. For short-term use, 2–8°C storage for several days is typical in literature, but verify stability empirically.
  • Avoid prolonged exposure to >25°C, strong light, or high pH to limit backbone hydrolysis and tyrosine oxidation.

• Documentation

  • Appearance, precise solubility limits, and molecular weight for this item are not specified; refer to the lot-specific CoA/Spec Sheet and SDS for authoritative details.

Structure and Identity

Poly(Lys, Tyr) hydrobromide is a synthetic polypeptide salt composed of lysine and tyrosine residues arranged in a random (statistical) copolymer backbone. It is typically provided as the hydrobromide (HBr) counterion form to neutralize cationic amino groups.

• Item-specific identifiers

  • CAS: 41705-04-8
  • SKU: P477638
  • Molecular Formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet. (Polymeric; average MW varies by lot.)
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.
  • InChIKey: Not specified for this item; refer to CoA/Spec Sheet.

• Structural features (general/literature description)

  • Backbone: peptide (–NH–CHR–CO–)n derived from α-amino acids.
  • Side chains:
    • Lysine: –(CH2)4–NH2 (primary ε-amine; cationic when protonated).
    • Tyrosine: –CH2–C6H4–OH (phenolic hydroxyl; aromatic ring).
  • Ionic form: hydrobromide salt; ε-amines (and possibly α-amines) are protonated with Br− as counterion.
  • Functional groups: primary amines, phenols, amide bonds, aromatic rings.
  • Stereochemistry: typically composed of L-amino acids (literature), yielding an optically active polypeptide; specific configuration/ratio not specified for this item.

• 2D structure (verbal depiction)

  • A repeating peptide chain with alternating/random lysine and tyrosine residues; each repeat bears either a pendant four-methylene primary amine (Lys) or a phenolic para-hydroxybenzyl (Tyr) substituent. The polymer is charge-dense under acidic/neutral conditions due to protonated amines, balanced by bromide anions.

Synthetic Utility

Poly(Lys, Tyr) hydrobromide offers a multifunctional scaffold for conjugation and materials synthesis in aqueous media.

• Functional handles

  • Primary amines (Lys): nucleophilic coupling to NHS esters, isothiocyanates, aldehydes (via Schiff base → reductive amination), and activated carbonates; can be acylated, sulfonylated, or carbamylated.
  • Phenolic hydroxyls (Tyr): sites for electrophilic aromatic substitution (e.g., diazonium coupling), enzymatic oxidative crosslinking (dityrosine), and halogenation/iodination under controlled conditions.

• Scaffolding and multivalency

  • High site density enables multivalent display of ligands, dyes, or affinity tags to create polymer–biomolecule conjugates, responsive films, or nanocomplexes.

• Immobilization strategies

  • Carbodiimide coupling to carboxylated surfaces; glutaraldehyde crosslinking after amine activation; oxidative coupling on phenol-derivatized interfaces to exploit tyrosine chemistry.

• Analytical considerations

  • Composition heterogeneity and average MW influence stoichiometry; use functional group assays (TNBS for amines, Folin–Ciocalteu or UV for phenols) to estimate available sites.

• Retrosynthetic perspective

  • The polymer acts as a macromolecular reagent and carrier rather than a building block toward small-molecule synthesis, streamlining assembly of complex, water-processable materials.

Target Specificity

This product is a synthetic polypeptide and is not an antibody, enzyme, or ligand with defined molecular targets. No item-specific target data are provided.

• Antigen/epitope: Not applicable.
• Species reactivity: Not applicable.
• Clone/isotype: Not applicable.

Use-cases depend on nonspecific electrostatic and adsorption interactions rather than specific biochemical binding.

Frequently Asked Questions

How should this product be stored?

Store at ?20 °C. Freezer storage is required to maintain the specified shelf life.

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 are the CAS number, molecular formula and molecular weight?

The CAS Number is 41705-04-8.

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.