CR 665

CR 665 is a synthetic peptide compound recognized for its potent and highly selective agonism of peripheral kappa opioid receptors (KORs). Structurally engineered to restrict central nervous system penetration, this peptide exhibits a distinct pharmacological profile that has made it a valuable tool in the investigation of peripheral opioid signaling pathways. Its unique selectivity and limited blood-brain barrier permeability allow researchers to dissect peripheral versus central opioid effects, advancing the understanding of pain modulation and receptor pharmacodynamics. As a research-use-only peptide, CR 665 has garnered significant interest in the fields of neuropharmacology, peptide chemistry, and receptor biology.

Receptor Pharmacology: CR 665 is widely utilized in studies exploring the pharmacological properties of kappa opioid receptors, particularly in peripheral tissues. By acting as a selective KOR agonist, it enables researchers to elucidate the downstream signaling mechanisms and physiological responses mediated by peripheral opioid receptor activation. Such studies are critical for mapping receptor distribution, characterizing ligand-binding profiles, and understanding the modulation of nociceptive pathways outside the central nervous system.

Peptide Structure-Activity Relationship (SAR) Analysis: The compound's synthetic peptide backbone and tailored amino acid sequence make it a valuable reference molecule for structure-activity relationship investigations. Researchers employ CR 665 as a benchmark in the rational design and optimization of peptide-based ligands targeting opioid receptors. Comparative SAR studies help identify key structural motifs responsible for receptor selectivity, potency, and peripheral restriction, informing the development of novel peptide therapeutics and research probes.

In Vivo Peripheral Selectivity Studies: Due to its minimal central nervous system penetration, CR 665 serves as a model compound in animal studies designed to differentiate peripheral from central opioid effects. Experimental protocols often use this peptide to assess peripheral nociception, inflammation, and other physiological processes modulated by KORs. The ability to selectively target peripheral receptors without confounding central side effects provides researchers with a powerful tool for evaluating the therapeutic potential and safety profiles of new opioid ligands.

Peptide Stability and Metabolism Research: The metabolic stability and enzymatic degradation of synthetic peptides are critical considerations in drug design and pharmacology. CR 665 is employed in studies investigating the stability, bioavailability, and metabolic fate of peripherally restricted peptide agonists. By analyzing its degradation kinetics and resistance to proteolytic enzymes, researchers gain insight into strategies for enhancing peptide durability and optimizing pharmacokinetic properties in related analogs.

Analytical Method Development: As a well-characterized peptide standard, CR 665 is used in the development and validation of analytical techniques such as high-performance liquid chromatography (HPLC) and mass spectrometry. These methods are essential for quantifying peptide concentrations, assessing purity, and ensuring batch-to-batch consistency in research and development settings. Its defined chemical structure and robust detection characteristics make it a preferred reference compound for calibrating and troubleshooting analytical workflows in peptide research laboratories.

1. Identification, Localization in the Central Nervous System and Novel Myostimulatory Effect of Allatostatins in Tenebrio molitor Beetle

2. GLP-1, exendin-4 and C-peptide regulate pancreatic islet microcirculation, insulin secretion and glucose tolerance in rats

3. Cell-based adhesion assays for isolation of snake venom’s integrin antagonists

4. High fat diet and GLP-1 drugs induce pancreatic injury in mice

5. Urinary Metabolites Associated with Blood Pressure on a Low-or High-Sodium Die