An atto-dye-labeled MyrB (Myrcludex B). Myrcludex B is an inhibitor of HBV and HDV infections.
Myrcludex B atto is a peptide API. This synthetic peptide is specifically designed to target the sodium taurocholate cotransporting polypeptide (NTCP) and is generated by conjugating Myrcludex B to the fluorescent dye Atto. Myrcludex B is a 47 amino acid synthetic peptide that mimics the preS1 domain of the large envelope protein of the hepatitis B virus (HBV). It effectively binds to the bile acid transporter NTCP on hepatocytes and inhibits HBV entry into hepatocytes. The attachment of the Atto dye allows researchers to visualize and track the distribution and cellular interactions of the peptide. The binding to the Atto fluorescent dye provides additional critical information. Using advanced microscopy techniques, researchers can monitor the real-time dynamics of Myrcludex B atto in the cellular environment. The specificity of this protein for NTCP and the fluorescent labeling make it a powerful tool for real-time studies of viral entry, drug distribution, receptor-ligand interactions, and pharmacokinetic behavior. Applications of Myrcludex B atto in drug discovery include:
1. Hepatitis B and D antiviral research: The primary application of Myrcludex B atto is antiviral research, particularly on HBV and hepatitis D virus (HDV). HBV is a major global health challenge that leads to chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Myrcludex B acts as an entry inhibitor, preventing the virus from infecting liver cells by blocking NTCP, which is also a receptor for HDV. Myrcludex B atto has dual functionality—it not only acts as a therapeutic agent to inhibit viral entry, but also as a fluorescent probe that allows researchers to track its effectiveness in real time. By observing how Myrcludex B atto distributes and interacts with host cells, researchers can optimize dosing strategies and more thoroughly understand the interaction dynamics of the drug, thereby improving the efficacy of subsequent treatment options.
2. Tracking liver-specific delivery: Understanding drug delivery and distribution within the liver is critical for developing liver disease therapies. Myrcludex B atto has significant advantages due to its liver-targeted properties. By specifically binding to NTCP on the surface of hepatocytes, Myrcludex B atto ensures selective delivery. In addition, the fluorescent properties of the Atto tag enable detailed microscopic visualization, allowing researchers to observe the distribution, retention, and hepatocyte engagement of compounds in real time. This is of great significance for evaluating the efficiency and specificity of drug delivery systems, optimizing formulations, and reducing off-target effects, thereby improving the safety and efficacy of treatments.
3. Receptor-ligand interaction studies: Drug discovery often relies on understanding receptor-ligand interactions at the molecular level. The fluorescent labeling of Myrcludex B atto allows precise visualization of these interactions. Researchers use techniques such as fluorescence microscopy, FRET (Förster resonance energy transfer), and FRAP (fluorescence recovery after photobleaching) to study binding kinetics, receptor internalization, and recycling processes. This in-depth visualization helps to depict the structural conformation of receptors, changes in affinity, and dynamic changes upon ligand binding.
4. Pharmacokinetic and biodistribution studies: Preclinical evaluation of novel therapeutic peptides requires rigorous pharmacokinetic and biodistribution studies. Myrcludex B atto achieves these goals by providing real-time, non-invasive tracking of the behavior of peptides in vivo. In animal models, researchers can use techniques such as live animal imaging to monitor the distribution of peptides in different tissues and organs. These studies derive key pharmacokinetic parameters such as absorption rate, bioavailability, metabolic stability and clearance, guiding the modification and enhancement of peptide drugs. Ultimately, this will lead to better drug candidates entering clinical development.
5. Study pathophysiological mechanisms: In addition to drug discovery, Myrcludex B atto is also a powerful research tool for exploring pathophysiological mechanisms involving NTCP and hepatocytes. For example, in liver disease models such as cholestasis, steatosis or fibrosis, the behavior of NTCP and its regulation can be observed using Myrcludex B atto.