Characterization of interactions between local anesthetics and histamine H1 receptor by cell membrane chromatography model

Construction and application of H1R ligand screening materials based on SMA stabilization and his-tag covalent immobilization of membrane proteins

The histamine H1 receptor (H1R) plays a pivotal role in allergy initiation and undergoes the necessity of devising a high-throughput screening approach centered on H1R to screen novel ligands effectively. This study suggests a method employing styrene maleic acid (SMA) extraction and His-tag covalent bonding to immobilize H1R membrane proteins, minimizing the interference of nonspecific proteins interference while preserving native protein structure and maximizing target exposure. This approach was utilized to develop a novel material for high-throughput ligand screening and implemented in cell membrane chromatography (CMC). An H1R-His-SMALPs/CMC model was established and its chromatographic performance (selectivity, specificity and lifespan) validated, demonstrating a significant enhancement in lifespan compared to previous CMC models. Subsequently, this model facilitated high-throughput screening of H1R ligands in the compound library and preliminary activity verification of potential H1R antagonists. Identification of a novel H1R antagonist laid the foundation for further development in this area.

Discovery of a novel series of pyridone amides as NaV1.8 inhibitors

The NaV1.8 channel, mainly found in the peripheral nervous system, is recognized as one of the key factors in chronic pain. The molecule VX-150 was initially promising in targeting this channel, but the phase II trials of VX-150 did not show expected pain relief results. By analyzing the interaction mode of VX-150 and NaV1.8, we developed two series with a total of 19 molecules and examined their binding affinity to NaV1.8 in vitro and analgesic effect in vivo. One compound, named 2j, stood out with notable activity against the NaV1.8 channel and showed effective pain relief in models of chronic inflammatory pain and neuropathic pain. Our research points to 2j as a strong contender for developing safer pain-relief treatments.

A new MAS-related G protein-coupled receptor X2 cell membrane chromatography analysis model based on HALO-tag technology and its applications

Cell membrane chromatography (CMC) is an effective method for studying receptors with multiple transmembrane structure such as MAS-related G protein-coupled receptor X2 (MrgX2). CMC relies on the maintenance of the complete biological structure of a membrane receptor; however, it needs to be further improved to obtain a more convenient and stable CMC model. In the present study, the haloalkane dehalogenase protein tag (HALO-tag) technology was used to construct a new MrgX2/CMC model. The fusion receptors of MrgX2 with HALO-tag at the C terminus were expressed in HEK293 cells. The silica gel was modified with a substrate of HALO-tag (chloroalkanes) via one-step acylation for the rapid capture of fusion receptors. The new CMC model (MrgX2-HALO-tag/CMC model) was not only quicker to prepare but also more stable and had a longer lifespan than a previous MrgX2-SNAP-tag/CMC model. In combination with the high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) system, the MrgX2-HALO-tag/CMC model was used to screen and identify bioactive components in traditional Chinese medicine. Using this combination, sanggenon C and morusin were identified from Mori Cortex as anti-pseudo-allergic components. The MrgX2-HALO-tag/CMC model alone was also applied to analyze ligand-receptor interaction. The affinity order of four ligands to MrgX2 was as follows: desipramine < imipramine < amitriptyline < clomipramine. This was consistent with the results obtained using the MrgX2-SNAP-tag/CMC model. The MrgX2-HALO-tag/CMC model provides ideas and application prospects for the immobilization of cell membrane that contains receptors with more transmembrane structures.

[Applications of chromatography in giant complex drug-organism system]

Chromatography is an important branch of analytical chemistry that focuses on the separation and analysis of complex structures. Following more than 100 years of development and improvement, chromatography theory and technology have gradually become sophisticated. It has become a coalition of science, technology, and art. Recently, chromatography has been successfully used in combination with mass spectrometry, nuclear magnetic resonance spectroscopy, and atomic emission spectroscopy. Chromatography and the combination with other techniques has significantly improved the analysis of complex systems, such as the environment, food, petrochemicals, biological specimens, and medicine. As one of the oldest healing systems, Traditional Chinese Medicine (TCM) has served to maintain the health of people in China and worldwide for thousands of years. Therefore, it has become a core representative of traditional Chinese culture. In the past two years, TCM has been widely used to treat COVID-19, especially in patients with mild symptoms. Recently, Chinese government emphasized the inheritance and innovation of TCM and stepped up efforts to promote its modernization. TCM includes herbal medicine, acupuncture, moxibustion, massage, food therapy, and physical exercise, such as Tai Chi. In most cases, the patients are administered a mixture of TCM formulas containing more than two herbal medicines, resulting in a highly complicated compound mixture. There is no doubt that long-term clinical practices have demonstrated the safety and therapeutic effect of TCM. However, the compound mixture must be simplified to identify the active compounds. This is mainly because of the existence of carcinogenic compounds, pesticides, and heavy metal residues introduced through plantation and production processes. Moreover, enzymes within the human system generate further new compounds in response to the entry of the TCM containing thousands of components. Consequently, the complex TCM and organism systems interact with each other, constituting a giant complex drug-organism system. The analysis of this giant complex system is acknowledged as a key aspect in the modernization process of TCM. In the last 20 years, many studies have been conducted to screen and identify effective compounds in TCM. These effective compounds can be either the original compounds or new metabolic components generated in vivo. All these efforts are aimed at simplifying the components of TCM and elucidating the therapeutic mechanism. It is well known that chromatography can provide technical support for complex systems owing to its unique advantage of outstanding separation and analysis capabilities. Therefore, chromatography and its combination with other technologies have become mainstream technologies for promoting the compilation of molecular structure, information, digitalization, and modernization of TCM. This paper reviews the research and application of chromatography and combination technologies in a giant complex TCM formula-organism system. Furthermore, the authors briefly introduce and summarize the understanding, research ideas, and activities of the authors' team on the modernization of TCM. "Liang Guanxi" and "He strategy" are proposed as novel strategies for studying the giant complex drug-organism system. A distinguished technology integrated with mathematical model of causal relation, combined receptor chromatography, identification of chemical molecular structure and evaluating of pharmacological activities was established. It was successfully employed to determine the core effector-response substances of "Liang Guanxi" herb pairs in a giant complex drug-organism system. Subsequently, utilizing the proposed technology of Combination of Traditional Chinese Medicine Molecular Chemistry, the author's team designed and developed four series of innovative drugs. Inspired by the hundred years of chromatography history and thousands of years of TCM culture, the future development of chromatographic technology is expected. Furthermore, the mechanisms of TCM in medical healthcare, prevention, and treatment of diseases are likely be explained through chromatography, leading to a new strategy to realize the molecularization and digitalization of TCM, which is beneficial to the development of original new drugs.