Lypressin Acetate | CAS 50-57-7 | Vasopressin V1a/V2 Receptor Agonist (Research Use Only) | Knowlux

Product Description

Lypressin Acetate, CAS 50-57-7, is a synthetic cyclic nonapeptide analogue of vasopressin in which arginine at position 8 is replaced by lysine, supplied by Knowlux for laboratory research use. The sequence is H-Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Lys-Gly-NH2, with a disulfide bridge between Cys1 and Cys6. The molecular formula is C46H65N13O12S2 and the molecular weight is 1056.22 g/mol (free peptide basis). Each lot is released with a lot-specific COA, MSDS and analytical traceability.

CAS and Salt Form Clarification: CAS 50-57-7 is the registry for the Lypressin free peptide and is the identifier consistently used by KEGG, ChemicalBook, Santa Cruz Biotechnology, and AssayGenie. The compound is supplied commercially in the acetate salt form under the product name "Lypressin Acetate," but the free peptide CAS 50-57-7 is applied to both free and salt forms across most supplier listings. No single acetate-salt CAS analogous to those assigned to Atosiban or Felypressin is consistently adopted in the Lypressin literature. A separate point of confusion concerns the acetate molecular weight: Molcore lists C48H69N13O14S2 with MW 1116.27, which corresponds to the monoacetate form (1056.22 + 60.05); MuseChem lists C48H68N12O15S2 with MW 1117.26, but this formula contains one fewer nitrogen than the free peptide (N12 versus N13) and does not reconcile with the established sequence. Knowlux declares the salt stoichiometry, acetate content, and water content per lot on the COA. Buyers should confirm the declared counter-ion basis against the reported molecular weight rather than relying on catalogue values alone.

Sequence and Structural Verification: The 9-residue sequence H-Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Lys-Gly-NH2 with a disulfide bridge between Cys1 and Cys6 is confirmed by KEGG, ChemicalBook, Santa Cruz Biotechnology, and AssayGenie. The C-terminus is glycinamide (Gly-NH2), amidated against carboxypeptidase degradation. Lypressin is the lysine-8 analogue of arginine vasopressin (Argipressin); the single Arg8-to-Lys8 substitution is the defining structural difference between the two peptides.

Product Parameters

Product Details

1. Overview

Lypressin (lysine vasopressin) is a synthetic nonapeptide analogue of vasopressin in which the arginine residue at position 8 is replaced by lysine. This substitution is the sole structural difference from arginine vasopressin (Argipressin), and it produces a pharmacological profile that retains both antidiuretic (V2-mediated) and vasoconstrictor (V1a-mediated) activities while shifting the V1a/V2 selectivity ratio relative to the native hormone. KEGG classifies Lypressin as a vasopressin analogue within the cardiovascular agent group (ATC code H01BA03) and annotates its targets as AVPR1 and AVPR2, with pathway involvement in calcium signaling, neuroactive ligand-receptor interaction, vascular smooth muscle contraction, and vasopressin-regulated water reabsorption. In clinical medicine, Lypressin has been used as an antidiuretic for central diabetes insipidus. The material supplied under this specification is research-grade and is not intended for human administration. Knowlux supplies this compound strictly for laboratory investigation of vasopressin receptor pharmacology, water homeostasis, and the structure-activity relationships that distinguish Lys8 from Arg8 analogues.

2. Receptor Pharmacology and Selectivity

Lypressin binds both V1a and V2 vasopressin receptor subtypes, but with a selectivity profile distinct from that of Argipressin. BenchChem reports Ki values of approximately 1.8 nM for V1a and approximately 10.0 nM for V2 for Lypressin, compared with approximately 0.8 nM (V1a) and approximately 0.85 nM (V2) for Argipressin. This comparison indicates that Lypressin is roughly 5.6-fold V1a-preferring (V1a Ki 1.8 nM versus V2 Ki 10.0 nM), whereas Argipressin is essentially non-selective (V1a Ki 0.8 nM versus V2 Ki 0.85 nM). Functionally, Lypressin behaves as a partial agonist at V1a receptors (calcium mobilization) and a full agonist at V2 receptors (cAMP accumulation), according to the same source. V1a and V1b receptors couple to Gq/11, activating phospholipase C and mobilizing intracellular calcium; V2 couples to Gs, activating adenylyl cyclase and elevating cAMP. These pharmacological values are assay- and system-dependent and are provided for scientific reference only. Researchers designing selectivity experiments should establish V1a/V2 potency ratios in their own assay systems rather than relying exclusively on literature Ki values.

3. Research Applications

Published pharmacological characterizations and documented protocols describe the following research applications:

• V1a and V2 receptor binding assays using filtration-based radioligand binding with [3H]-AVP

• V2-mediated cAMP accumulation assays in cells stably expressing the human V2 receptor

• Vasopressin-regulated aquaporin-2 (AQP2) trafficking studies in renal collecting duct models

• Structure-activity relationship comparisons between Lys8 (Lypressin) and Arg8 (Argipressin) vasopressin analogues

• Reference standard development for HPLC and LC-MS analytical methods

These descriptions are derived from published research and are provided for scientific reference only. They do not constitute clinical guidance or dosing recommendations.

Quality Control

Solubility and Handling

Solubility: Lypressin Acetate is soluble in water and in dilute acetic acid, but the reported concentrations vary substantially by source and are not directly interchangeable. Santa Cruz Biotechnology lists solubility of 1 mg/mL in water and 20 mg/mL in 0.1M acetic acid. AssayGenie recommends reconstitution in sterile 18 megaohm-cm water at not less than 100 micrograms/mL, with further dilution into aqueous solutions, and notes that the peptide is also soluble in 1% acetic acid. Cell Sciences lists solubility in 1% acetic acid. The higher solubility in dilute acetic acid relative to neutral water is consistent with the peptide's basic character and should be considered when selecting a solvent system. For stock solutions, 0.1M acetic acid is preferable where the assay tolerates acidic pH; water is suitable for lower-concentration working solutions. Prepare solutions fresh and aliquot to avoid repeated freeze-thaw cycles.

Handling Precautions: Use powder-handling containment (glove box or fume hood with particulate control). Avoid inhalation of fine powder. ChemicalBook assigns GHS07 (warning, H332, harmful if inhaled) for CAS 50-57-7. Wear nitrile gloves, lab coat, and eye protection. The disulfide bridge is sensitive to reducing agents; avoid contact with dithiothreitol (DTT) or mercaptoethanol during handling. Follow institutional chemical hygiene plans for research peptides.

Storage and Stability

Documentation Support

Per lot: COA, MSDS, certificate of origin, HPLC chromatogram, and mass spectrometry data. Acetate content, water content, and peptide content data available on request. Custom specifications and third-party inspection can be arranged on a project basis.

About Knowlux

Knowlux Biotechnology is a GMP-oriented manufacturer and supplier of peptides, APIs and fine-chemical research compounds, operating from Hubei, China. We serve research groups, CDMOs and distributors in more than 40 countries, and support contract synthesis, custom packaging and technical documentation requests.

Compliance Statement

FOR RESEARCH USE ONLY. NOT FOR HUMAN USE. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE.

This product is supplied for laboratory research use only. It is not for human or animal administration, not for diagnostic or therapeutic use, not for retail sale, and not for personal use. Lypressin has been used clinically as an antidiuretic in certain jurisdictions; however, the material offered under this specification is research-grade and is not intended for clinical use. The purchaser is responsible for verifying product specifications against their specific research requirements and for compliance with all applicable institutional, local, and national regulations governing research chemical acquisition, storage, and use. Research context statements are for scientific reference only and do not constitute medical advice, promotional claims, or dosing guidance.

Data Verification Notes: The molecular formula C46H65N13O12S2 and molecular weight 1056.22 g/mol are confirmed by KEGG, ChemicalBook, Santa Cruz Biotechnology, AssayGenie, and multiple supplier COAs. The sequence Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Lys-Gly-NH2 with disulfide bridge Cys1-Cys6 is consistent across KEGG, ChemicalBook, Santa Cruz Biotechnology, and AssayGenie. The acetate salt molecular weight assignment is addressed explicitly: Molcore's 1116.27 (C48H69N13O14S2) is consistent with a monoacetate, while MuseChem's 1117.26 with formula C48H68N12O15S2 contains one fewer nitrogen than the free peptide and does not reconcile with the established sequence; the latter is treated as a data entry error and not adopted. The Ki values (Lypressin V1a ~1.8 nM, V2 ~10.0 nM; AVP V1a ~0.8 nM, V2 ~0.85 nM) are from BenchChem's compiled pharmacology tables and are approximate, assay-dependent values. The functional classification of Lypressin as a V1a partial agonist and V2 full agonist is likewise from BenchChem and should be confirmed in the user's assay system. Storage guidance divergence, particularly the AssayGenie do not freeze instruction, is reported as-is rather than reconciled into a single blanket recommendation, because the underlying stability datasets were generated under different conditions and for different product formats.

Formatting Note: All formulas, sequences, and comparison operators use plain ASCII notation to prevent character corruption on the platform. Section headings, table alignment, and spacing follow the approved product detail pattern. No trailing spaces or non-breaking characters are used; tables use consistent pipe alignment.