Dynorphin A (1-9) , CAS No.77259-54-2

CAS: 77259-54-2 Cat. No.: D934876 PubChem CID: 3081578

Storage

Room temperature

Specifications

Storage

Room temperature

Names and Identifiers

• Canonical Smiles: CCC(C)C(C(=O)NC(CCCN=C(N)N)C(=O)O)NC(=O)C(CCCN=C(N)N)NC(=O)C(CCCN=C(N)N)NC(=O)C(CC(C)C)NC(=O)C(CC1=CC=CC=C1)NC(=O)CNC(=O)CNC(=O)C(CC2=CC=C(C=C2)O)N
• IUPAC Name: (2S)-2-[[(2S,3S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[2-[[(2S)-2-amino-3-(4-hydroxyphenyl)propanoyl]amino]acetyl]amino]acetyl]amino]-3-phenylpropanoyl]amino]-4-methylpentanoyl]amino]-5-(diaminomethylideneamino)pentanoyl]amino]-5-(diaminomethylideneamino)pentanoyl]amino]-3-methylpentanoyl]amino]-5-(diaminomethylideneamino)pentanoic acid
• InChIKey: CZWWJMLXKYUVTQ-VCZUSBFASA-N
• INCHI: 1S/C52H84N18O11/c1-5-30(4)42(48(79)68-37(49(80)81)16-11-23-62-52(58)59)70-45(76)36(15-10-22-61-51(56)57)66-44(75)35(14-9-21-60-50(54)55)67-46(77)38(24-29(2)3)69-47(78)39(26-31-12-7-6-8-13-31)65-41(73)28-63-40(72)27-64-43(74)34(53)25-32-17-19-33(71)20-18-32/h6-8,12-13,17-20,29-30,34-39,42,71H,5,9-11,14-16,21-28,53H2,1-4H3,(H,63,72)(H,64,74)(H,65,73)(H,66,75)(H,67,77)(H,68,79)(H,69,78)(H,70,76)(H,80,81)(H4,54,55,60)(H4,56,57,61)(H4,58,59,62)/t30-,34-,35-,36-,37-,38-,39-,42-/m0/s1
• Isomeric SMILES: CC[C@H](C)[C@@H](C(=O)N[C@@H](CCCN=C(N)N)C(=O)O)NC(=O)[C@H](CCCN=C(N)N)NC(=O)[C@H](CCCN=C(N)N)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CC1=CC=CC=C1)NC(=O)CNC(=O)CNC(=O)[C@H](CC2=CC=C(C=C2)O)N
• Alternate CAS: 77259-54-2
• PubChem CID: 3081578
• MeSH Entry Terms: dynorphin A (1-9)

Taxonomic Classification

Taxonomy Tree

• Kingdom Organic compounds
  • Superclass Organic acids and derivatives
    • Class Carboxylic acids and derivatives
      • Subclass Amino acids, peptides, and analogues
        • Level5 Peptides
          • Level6 Oligopeptides

• Kingdom: Organic compounds
• Superclass: Organic acids and derivatives
• Class: Carboxylic acids and derivatives
• Subclass: Amino acids, peptides, and analogues
• Intermediate Tree Nodes: Peptides
• Direct Parent: Oligopeptides
• Alternative Parents: Tyrosine and derivatives Phenylalanine and derivatives Isoleucine and derivatives Leucine and derivatives N-acyl-L-alpha-amino acids Alpha amino acid amides Amphetamines and derivatives 1-hydroxy-2-unsubstituted benzenoids Aralkylamines N-acyl amines Secondary carboxylic acid amides Guanidines Amino acids Monocarboxylic acids and derivatives Propargyl-type 1,3-dipolar organic compounds Carboxylic acids Carboximidamides Monoalkylamines Hydrocarbon derivatives Carbonyl compounds Organic oxides
• Molecular Framework: Aromatic homomonocyclic compounds
• Substituents: Alpha-oligopeptide - Tyrosine or derivatives - Phenylalanine or derivatives - Leucine or derivatives - Isoleucine or derivatives - N-acyl-alpha-amino acid - N-acyl-alpha amino acid or derivatives - N-acyl-l-alpha-amino acid - Alpha-amino acid amide - N-substituted-alpha-amino acid - Alpha-amino acid or derivatives - Amphetamine or derivatives - 1-hydroxy-2-unsubstituted benzenoid - Phenol - Aralkylamine - N-acyl-amine - Fatty acyl - Fatty amide - Benzenoid - Monocyclic benzene moiety - Amino acid - Secondary carboxylic acid amide - Carboxamide group - Guanidine - Amino acid or derivatives - Organic 1,3-dipolar compound - Propargyl-type 1,3-dipolar organic compound - Carboximidamide - Carboxylic acid - Monocarboxylic acid or derivatives - Amine - Organic oxide - Carbonyl group - Organic oxygen compound - Organic nitrogen compound - Primary amine - Organooxygen compound - Primary aliphatic amine - Hydrocarbon derivative - Organonitrogen compound - Aromatic homomonocyclic compound
• Description: This compound belongs to the class of organic compounds known as oligopeptides. These are organic compounds containing a sequence of between three and ten alpha-amino acids joined by peptide bonds.
• External Descriptors: Not available

Data sources

1. Djoumbou Feunang Y, Eisner R, Knox C, Chepelev L, Hastings J, Owen G, Fahy E, Steinbeck C, Subramanian S, Bolton E, Greiner R, and Wishart DS. ClassyFire: Automated Chemical Classification With A Comprehensive, Computable Taxonomy. Journal of Cheminformatics, 2016, 8:61.

DOI: 10.1186/s13321-016-0174-y

Chemical and Physical Properties

• Molecular Weight: 1137.300 g/mol
• XLogP3: -5.200
• Hydrogen Bond Donor Count: 17
• Hydrogen Bond Acceptor Count: 15
• Rotatable Bond Count: 37
• Exact Mass: 1136.66 Da
• Monoisotopic Mass: 1136.66 Da
• Topological Polar Surface Area: 510.000 Ų
• Heavy Atom Count: 81
• Formal Charge: 0
• Complexity: 2120.000
• Isotope Atom Count: 0
• Defined Atom Stereocenter Count: 8
• Undefined Atom Stereocenter Count: 0
• Defined Bond Stereocenter Count: 0
• Undefined Bond Stereocenter Count: 0
• The total count of all stereochemical bonds: 0
• Covalently-Bonded Unit Count: 1

Application Protocols

Item-specific validated applications, recommended dilutions, and controls: Not specified for this item; refer to CoA/Spec Sheet.

General usage examples (literature/practice) for Dynorphin A (1-9):

• Radioligand binding: Prepare serial dilutions (e.g., 0.1–1000 nM) in assay buffer; incubate membranes expressing KOR with a fixed tracer and increasing peptide concentrations; separate bound/free by filtration and quantify displacement.
• Functional signaling assays: Use cAMP inhibition, GTPγS binding, or β-arrestin recruitment platforms; generate concentration–response curves to estimate EC50/IC50.
• LC–MS reference: Spike a known amount into a matrix to evaluate recovery, retention time stability, and MS response factors; use isotopically labeled internal standards where available.

Practical notes:

• Minimize nonspecific adsorption by using low-binding plastics and adding carrier proteins if compatible.
• Validate tolerance to any co-solvent (e.g., DMSO ≤1% v/v) in cell-based assays.
• Employ fresh aliquots to avoid repeated freeze–thaw cycles.

These examples are provided as general guidance only; optimize conditions for your specific system.

Biological Roles

Literature/general background:

• Origin: Dynorphin A peptides are endogenously produced through proteolytic processing of prodynorphin (preproenkephalin B). The (1–9) fragment comprises the N-terminal nonapeptide YGGFLRRIR.
• Receptor interactions: Dynorphin A fragments act primarily at opioid receptors. The full-length Dyn A(1–17) shows high affinity and selectivity for the kappa opioid receptor (KOR). The (1–9) truncation retains substantial KOR activity, with reduced length-dependent potency relative to longer fragments; cross-reactivity with mu (MOR) and delta (DOR) receptors is generally lower than for KOR, but assay- and species-dependent (literature).
• Structural determinants: The N-terminal YGGF motif is a conserved opioid pharmacophore essential for receptor recognition, while the basic residues (RR…R) contribute to receptor selectivity and binding kinetics (literature).
• Functional outcomes in research systems: Engagement of KOR typically leads to Gi/o signaling, inhibition of adenylyl cyclase, modulation of ion channels, and recruitment of β-arrestins, measurable via cAMP, GTPγS binding, calcium flux, or BRET-based assays (literature).
• Metabolism and stability: Peptidases readily cleave dynorphin fragments; common sites include the Tyr–Gly junction and basic residue pairs. Stabilization strategies (e.g., terminal protection, D-amino acid substitutions) are often explored in SAR but are not implied for this specific item unless stated on the CoA (not specified here).

Note: The above reflects general biological context to guide experimental design; it does not constitute clinical or therapeutic claims.

Buffer Applications

Item-specific buffer recommendations: Not specified for this item; refer to CoA/Spec Sheet.

General guidance for preparing Dynorphin A (1-9) solutions (literature/practice):

• Stock solutions: Dissolve in water, PBS, or HEPES buffer. If initial dissolution is difficult, wet with 0.1% acetic acid or 0.1% TFA, then dilute into the target buffer to the desired pH.
• Working concentrations: Typical ranges for receptor assays span 0.1–1000 nM for binding and functional response curves; exact concentrations are assay- and system-dependent (literature).
• pH: Maintain near-neutral pH (≈6.8–7.4) for live-cell assays. Slightly acidic pH can improve solubility for stock but should be adjusted prior to biological application.
• Additives: To mitigate adsorption, consider 0.1% BSA or 0.01–0.1% Tween-20 if compatible with the assay. Include protease inhibitors for stability in complex matrices (e.g., plasma or tissue homogenates).
• Filtration/sterility: Sterile filter through a 0.22 µm low-protein-binding membrane for cell-based experiments. Avoid repeated freeze–thaw by aliquoting.

Recipe hints (general):

• Example solvent system: 10 mM HEPES, 150 mM NaCl, pH 7.4.
• For analytical LC–MS: Use volatile buffers (e.g., 0.1% formic acid in water), avoiding non-volatile salts that suppress ionization.

All parameters should be validated for the intended assay; consult the CoA/SDS for item-specific constraints.

Green Alternatives

Peptides such as Dynorphin A (1-9) are generally handled in aqueous media, which aligns well with green chemistry principles. Key considerations (literature/general):

• Prefer water-based buffers over organic solvents whenever possible. Most assays can be executed in PBS, HEPES, or similar physiological buffers.
• If a co-solvent is needed, minimize DMSO content and validate its effect on the biological assay. Ethanol can sometimes substitute at low percentages, but may denature proteins in receptor/cell systems.
• Avoid halogenated solvents; they provide no advantage for dissolving this basic peptide and add disposal burdens.

Comparison (general):

• Water/buffer: Highest EHS profile; minimal waste hazard; compatible with bioassays.
• 0.1% acetic acid: Slightly more corrosive but enhances solubility of basic peptides; readily neutralized on dilution.
• DMSO: Effective for concentrated stocks; use sparingly due to persistence and biological effects.

Waste minimization:

• Prepare only the quantity needed for near-term use to reduce disposal of expired solutions.
• Use small-volume aliquots to prevent repeated freeze–thaw and premature disposal of degraded material.

These recommendations are general. For this specific item, no special green-chemistry hazards are indicated in the Product Data; consult the SDS for disposal guidance.

Pharmaceutical Uses

No therapeutic or clinical use is claimed or implied for this product. For research use only.

General formulation/manufacturing context (literature/practice):

• Analytical reference: Dynorphin A fragments may serve as reference standards for method development and system suitability testing in peptide analytics (e.g., RP‑HPLC, LC–MS), aiding identity and retention time verification.
• Excipient status: Not applicable; this peptide is an active sequence, not used as an excipient in typical formulations.
• Impurity profiling: In peptide manufacturing research, short dynorphin fragments can be used as process controls to evaluate purification efficiency, ion-pairing effects, and chromatographic selectivity.
• Stability studies: Model peptide to benchmark degradation pathways (oxidation of Tyr, backbone cleavage) under ICH-like stress conditions, though such studies are research-oriented and not product-specific.

Item-specific pharmacopeial status, GMP compliance, endotoxin/bioburden limits, and release specifications are not provided for this item; refer to the CoA/Spec Sheet if applicable.

Physical Properties

Item-specific properties: Not specified for this item; refer to CoA/Spec Sheet.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular Formula: Not specified for this item; refer to CoA/Spec Sheet.
• Melting point, density, refractive index, pKa values: Not specified for this item; refer to CoA/Spec Sheet.

Literature/general characteristics for Dynorphin A fragments:

• Physical state: Typically a white to off-white amorphous solid/lyophilized powder (peptide standard; literature, general).
• Solubility: Short basic peptides like Dyn A (1-9) are generally soluble in water and aqueous buffers; initial wetting with a small volume of 0.1% acetic acid or 0.1% TFA can facilitate dissolution. If needed, DMSO can be used to prepare a concentrated stock prior to dilution into buffer (literature, general). Actual solubility depends on counter-ions and salt form.
• Hygroscopicity: Many peptides are hygroscopic and can absorb moisture, impacting weighings and stability (literature, general).
• Ionization: Strongly basic due to multiple arginine residues; net charge is positive under physiological pH when termini are unprotected (literature, general).

Notes:

• Precise numeric values (e.g., extinction coefficient, pI, logP) are sequence- and salt-form dependent and are not specified for this product. Consult the CoA/Spec Sheet for item-specific analytical data.

Quality & Grades

Item-specific quality details (grade/purity, stabilizers, analytical specs): Not specified for this item; refer to CoA/Spec Sheet.

General guidance for peptide quality (literature/practice):

• Peptide grade terminology: Research grade typically indicates identity confirmed by MS and purity assessed by HPLC (often reported as area %). Higher grades may include additional tests (e.g., residual solvents, water content, counter‑ion analysis, TFA content, peptide content by AAA, bacterial endotoxin, and bioburden).
• Purity reporting: HPLC purity is commonly provided as % by UV at a specified wavelength and gradient. MS provides molecular identity; supplemental characterization may include HRMS, MALDI-TOF, and sometimes NMR for small peptides.
• Counter-ions and salt form: TFA salt vs acetate vs hydrochloride can influence solubility, pH upon dissolution, and mass balance. Item-specific counter‑ion content is best obtained from the CoA.
• Impurities: Typical peptide-related impurities include truncations, deletions, oxidized variants (e.g., Tyr oxidation), and residual protecting group remnants. Analytical methods such as RP‑HPLC and LC–MS are used to quantify.
• Use considerations: For bioassays (e.g., receptor binding), higher purity and low TFA content may reduce background effects. For analytical standards, well-defined salt form and counter-ion quantification improve reproducibility.

For this specific catalog entry, please consult the CoA/Spec Sheet for definitive grade, purity (%), salt form, and analytical acceptance criteria.

Reaction & Applications

This product is a bioactive peptide fragment and is not typically used as a chemical reagent or solvent in synthetic transformations. Therefore, traditional reaction families (e.g., cross-couplings, oxidations, organometallic formations) are not applicable.

Relevant research applications (literature/general) include:

• Receptor pharmacology: Dynorphin A fragments are used as reference ligands in kappa opioid receptor (KOR) binding and signaling assays (e.g., radioligand displacement, G-protein or β-arrestin readouts).
• Peptide benchmarking: Positive control in assay development and validation for opioid peptide detection (LC–MS) and for chromatographic method development.
• Structure–activity relationship (SAR): Comparative studies of truncations and analogs to map residues critical for receptor affinity and efficacy.
• Proteolysis studies: Substrate in peptidase assays to assess stability, degradation pathways, and metabolite profiling.

Practical tips (general):

• Prepare fresh working solutions and minimize adsorption to plastics by using low-binding tubes; addition of carrier protein (e.g., 0.1% BSA) can reduce nonspecific binding if compatible with the assay.
• Control for counter-ions (TFA/acetate) and pH, as these can influence receptor responses and assay baselines.
• For quantitative work, verify concentration by amino acid analysis or UV (if extinction coefficient at 280 nm for Tyr is used), adjusting for counter‑ion/water content when available from the CoA.

Reaction Conditions

Not typically applicable: Dynorphin A (1-9) is a finished peptide reagent intended for bioassays and analytical use, not for participation as a reagent/solvent in classical organic reactions.

General, literature-based handling conditions for peptide manipulations:

• Dissolution: Water or aqueous buffers; if needed, pre-wet with 0.1% acetic acid or TFA. DMSO acceptable for concentrated stocks before aqueous dilution.
• Temperature: Prepare and handle at ambient temperature; for long incubations in biological systems, maintain physiological temperatures (e.g., 37 °C) as dictated by the assay.
• Light/Oxygen: Protect from prolonged exposure to light and air if oxidative degradation (e.g., Tyr oxidation) is a concern; consider degassing buffers for sensitive studies.
• Stability windows: Working solutions are best prepared fresh. Time-dependent degradation can occur due to proteolysis or hydrolysis; inclusion of protease inhibitors is recommended in complex biological matrices.

If chemical modification of the peptide is undertaken as a separate research activity (not product-specified), standard peptide conjugation conditions (e.g., NHS ester labeling at pH 7.5–8.5 for N‑terminus/lysine, CuAAC when an azide/alkyne handle is present) apply, with careful control to avoid arginine side-chain interference.

Safety & Handling

Item-specific hazard information:

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

General laboratory safety for research peptides (literature/good practice):

• Avoid inhalation of dust and contact with skin/eyes. Handle powders in a fume hood or with local exhaust ventilation to minimize aerosolization.
• Personal protective equipment (PPE): laboratory coat, safety glasses, and suitable disposable gloves (e.g., nitrile). Change gloves regularly.
• Incompatibilities: Strong oxidizers may degrade peptides; avoid extreme pH for prolonged periods (acidic or basic hydrolysis can occur). Protect from moisture to prevent clumping or hydrolysis.
• First aid (overview; defer to SDS): If inhaled, move to fresh air; if on skin, wash with soap and water; if in eyes, rinse cautiously with water for several minutes; if ingested, rinse mouth with water. Seek medical attention if irritation persists.
• Spills: Gently dampen to avoid dust, collect with disposable towels, and dispose of as laboratory chemical waste. Clean area with water/appropriate detergent.
• Stability considerations: Peptides may undergo deamidation, oxidation (e.g., Tyr), or backbone cleavage under harsh conditions; store as directed and minimize freeze–thaw of solutions.

Always consult the product SDS for authoritative and item-specific safety guidance.

Solvent Selection

Item-specific solvent/solubility data: Not specified for this item; refer to CoA/Spec Sheet.

General guidance for dissolving Dynorphin A (1-9) (literature/practice):

• Primary choice: Water or aqueous buffers (e.g., PBS, HEPES) at neutral to slightly acidic pH. Initial wetting with 0.1% acetic acid or 0.1% TFA can help dissolve basic peptides by forming soluble salts.
• Co-solvents: If required, prepare a concentrated stock in DMSO (e.g., 10–50 mM), then dilute into aqueous media with vigorous mixing to minimize precipitation. Keep final DMSO below assay tolerance (commonly ≤0.1–1% v/v, assay-dependent).
• pH considerations: Highly basic peptides are more soluble at mildly acidic pH where cationic side chains are protonated. Avoid strong base; prolonged high pH can promote degradation.
• Ionic strength: Addition of salts can screen charge–charge interactions and reduce aggregation, but excessive ionic strength may cause salting-out in some buffers.
• Filtration: Use low-protein-binding filters (e.g., PVDF, PTFE, PES) for sterilization. Avoid cellulose acetate if peptide binding is suspected.

Comparison (general):

• Water/buffer: Greenest, biocompatible; best first choice for bioassays.
• Dilute acetic acid/TFA: Effective for initial dissolution; ensure compatible with downstream assays and neutralize/dilute as needed.
• DMSO: Useful for high-concentration stocks; consider potential biological effects and maintain low final percentages.

Storage & Reconstitution

Item-specific storage (from Product Data):

• Storage Conditions: Room temperature
• Shipped In: Not specified for this item; refer to CoA/Spec Sheet.

General reconstitution guidance for peptides (literature/practice):

• Reconstitution: Start with sterile water or buffer. If needed, pre-wet with 0.1% acetic acid or 0.1% TFA to aid solubilization before adjusting to final buffer/pH. Gentle vortexing and brief sonication can help.
• Concentrated stocks: Optionally prepare in DMSO, then dilute into aqueous media immediately before use. Verify assay compatibility.
• Aliquoting: Divide reconstituted solution into single-use aliquots to prevent repeated freeze–thaw.

Storage after reconstitution (general best practice):

• Short term (hours–days): 2–8 °C, protected from light.
• Long term (weeks–months): −20 °C or below; avoid frost-free cycles. Include antimicrobial agents only if compatible with downstream assays.
• Stability: Peptide stability is sequence- and matrix-dependent; monitor by HPLC/LC–MS as needed. Avoid prolonged exposure to high pH and strong oxidants.

Note: The above solution storage recommendations are general best practices for peptides and do not override the Product Data. Always consult the product CoA/SDS for item-specific guidance on storage, shelf life, and reconstitution conditions.

Structure & Identity

Brief description: Dynorphin A (1-9) is a 9-residue N-terminal fragment of the endogenous opioid peptide dynorphin A, commonly used as a research ligand/standard in opioid receptor studies.

Item-specific (from Product Data):

• SKU: D934876
• Product Name: Dynorphin A (1-9)
• CAS: 77259-54-2
• InChIKey: 57961 (as provided)
• Storage Conditions: Room temperature
• Research Use Note: For research use only

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

Literature/general identity (for context):

• Common amino acid sequence for Dynorphin A (1-9): Tyr–Gly–Gly–Phe–Leu–Arg–Arg–Ile–Arg (YGGFLRRIR).
• Class: Endogenous opioid neuropeptide fragment derived from prodynorphin.
• Structural features (2D description): linear peptide with an N-terminal phenolic aromatic ring (Tyr), a Gly–Gly motif, a hydrophobic/aromatic core (Phe, Leu, Ile), and a highly basic C-terminal region containing three Arg residues (guanidinium groups). The peptide contains a free N-terminus (–NH2/–NH3+ depending on pH) and a free C-terminus (–COOH/–COO− depending on pH), unless otherwise modified (not specified here).
• Stereochemistry: L-amino acids in the natural sequence (literature).

Synthetic Utility

As a defined bioactive peptide, this product is typically an assay ligand or analytical standard rather than a building block for further chemical synthesis. Nevertheless, it has utility in peptide science and method development (literature/general):

• SPPS benchmarking: Serves as a test sequence for solid-phase peptide synthesis (SPPS) optimization, particularly for handling multiple arginine residues and hydrophobic insertions (Phe, Leu, Ile). Useful for evaluating coupling reagents (e.g., HBTU/HATU/DIC–Oxyma) and guanidinium-protecting group removal.
• Chromatographic development: A model cationic peptide for optimizing RP‑HPLC gradients, ion-pairing conditions (e.g., TFA vs formic acid), and stationary phase selection.
• Enzymology substrate: Probe for protease specificity and kinetics in endopeptidase/exopeptidase assays, generating defined fragments detectable by LC–MS.
• Derivatization studies: Platform for N‑terminal or side-chain selective modifications (e.g., NHS esters, click handles) to create labeled analogs for imaging or assay readout, performed as separate research transformations (not modifications implied for this catalog item).

Limitations:

• Sequence-specific properties (aggregation, adsorption) may complicate reactions and purifications; use low-binding plastics and validate recovery.
• For covalent chemistry on this peptide, control pH to preserve arginine guanidinium functionality and avoid undesired side reactions.

Target Specificity

Item-specific target data (antigen, epitope, clone/isotype, species reactivity, Kd/Ki/EC50): Not specified for this item; refer to CoA/Spec Sheet.

Literature/general context:

• Dynorphin A fragments are widely used as ligands for the kappa opioid receptor (KOR), with varying selectivity and potency depending on fragment length and assay system. The (1–9) fragment retains significant KOR affinity relative to longer dynorphin peptides but typically exhibits reduced potency versus Dyn A(1–13)/(1–17). Cross-reactivity with MOR/DOR is possible and should be empirically determined for the specific assay conditions.

For definitive, item-specific binding constants or selectivity profiles, consult experimental data generated under your laboratory conditions or any assay data provided on the CoA.