G protein

GPCRs are a large family of cell surface receptors that respond to a variety of external signals. Binding of a signaling molecule to a GPCR results in G protein activation, which in turn triggers the production of any number of second messengers. GPCRs play an important role in the human body, and increased understanding of these receptors has greatly affected modern medicine. In fact, researchers estimate that between one-third to one-half of all approved drugs act by binding to GPCRs. GPCRs are a large group of drug targets in drug discovery.

MCE provides a unique collection of 3,070 small molecules targeting GPCRs that can be used in the screening for various GPCRs-related research and drug development projects.

Peptidomimetics are compounds whose essential elements (pharmacophore) mimic a natural peptide or protein in 3D space and which retain the ability to interact with the biological target and produce the same biological effect. Peptidomimetics are designed to circumvent some of the problems associated with a natural peptide: e.g. stability against proteolysis (duration of activity) and poor bioavailability. Certain other properties, such as receptor selectivity or potency, often can be substantially improved. The design and synthesis of peptidomimetics are most important because of the dominant position peptide and protein-protein interactions play in molecular recognition and signaling, especially in living systems. Hence mimics have great potential in drug discovery.

MCE Peptidomimetic Library contains 370 compounds including peptoid, α-helix mimetics, β-turn/sheets mimetics, etc. This library is an indispensable tool of structure-activity relationships in drug discovery.

Boronic acid and boronic ester represent a relatively novel and promising chemical structure in drug design. Boronic acid exists in an sp²-hybridized state, possessing an empty p-orbital that can act as a Lewis acid to accept lone pairs from heteroatoms (O, N, or S). This Lewis acidity enables it to form reversible covalent bonds with amino acid residues such as lysine, serine, threonine, and histidine. Currently, five FDA-approved drugs containing boronic acid or boronic ester predominantly involve such covalent binding mechanisms in their interactions with target proteins. Furthermore, boronic acid can serve as a bioisostere for carboxylic acids, phosphates, and phenolic groups, utilized to improve pharmacokinetic properties and enhance drug efficacy.

To date, five boron-containing drugs have been approved by the FDA. The unique properties of boronic acids and boronic esters confer significant potential in drug design, with applications spanning cancer therapy (e.g., multiple myeloma), anti-infectives (e.g., fungal infections, tuberculosis), anti-inflammatory treatments (e.g., atopic dermatitis), antibacterial agents (e.g., carbapenem-resistant bacterial infections), and Reactive Oxygen Species (ROS)-responsive prodrugs, among others. The MCE Boronic Acid/Boronic Ester Fragment Library, which contains over 1600 compounds, serves as a valuable tool for the development of boron-containing drugs.

Neurotransmitter (NT) receptors, also known as neuroreceptors, are a broadly diverse group of membrane proteins that bind neurotransmitters for neuronal signaling. There are two major types of neurotransmitter receptors: ionotropic and metabotropic. Ionotropic receptors are ligand-gated ion channels, meaning that the receptor protein includes both a neurotransmitter binding site and an ion channel. The binding of a neurotransmitter molecule (the ligand) to the binding site induces a conformational change in the receptor structure, which opens, or gates, the ion channel. The term “metabotropic receptors” is typically used to refer to transmembrane G-protein-coupled receptors. Metabotropic receptors trigger second messenger-mediated effects within cells after neurotransmitter binding.

In some neurological diseases, the neurotransmitter receptor itself appears to be the target of the disease process. Many neuroactive drugs act by modifying neurotransmitter receptors. A better understanding of neurotransmitter receptor changes in disease may lead to improvements in therapy.

MCE designs a unique collection of 2,278 compounds targeting a variety of neurotransmitter receptors. MCE Neurotransmitter Receptor Compound Library is a useful tool for neurological diseases drug discovery.

GABA receptors are a class of receptors that respond to the neurotransmitter gamma-aminobutyric acid (GABA), the chief inhibitory neurotransmitter in the vertebrate central nervous system. There are two classes of GABA receptors: GABAA and GABAB. GABAA receptors are ligand-gated ion channels (also known as ionotropic receptors), whereas GABAB receptors are G protein-coupled receptors (also known asmetabotropic receptors). GABA receptors are significant drug targets in the treatment of neuropsychiatric disorders such as epilepsy, insomnia, and anxiety, as well as in anesthesia in surgical operations.

MCE offers a unique collection of 182 GABA receptors inhibitors and activators, which is an efficient tool for neuropsychiatric disorders drugs discovery.

Membrane receptors, also known cell surface receptors or transmembrane receptors, are transmembrane proteins embedded into the plasma membrane which play an essential role in maintaining communication between the internal processes within the cell and various types of extracellular signals. They act in cell signaling by receiving (binding to) extracellular molecules, which are also called ligands. These extracellular molecules include hormones, cytokines, growth factors, neurotransmitters, lipophilic signaling molecules such as prostaglandins, and cell recognition molecules.

There are three kinds of membrane receptors: ion channel-linked receptors, enzyme-linked receptors and G-protein-linked receptors. They play important roles in keeping human normal physiologic processes. GPCRs and ion channels are important drug targets in drug discovery.

MCE provides a unique collection of 6,186 compounds targeting a variety of membrane receptors. MCE Membrane reeptor-targeted Compound Library can be used for membrane receptor-focused screening and drug discovery.

Dopamine receptor (DAR), widely distributed in the brain, plays a key role in regulating motor function, motivation, driving force and cognition. The role of DA is mediated by D1-type (D1, D5) and D2-type receptors (D2S, D2L, D3, D4), which are distributed in presynaptic, postsynaptic and extrasynaptic, projection neurons and interneurons. Each receptor has a different function. D1 and D5 receptors couple with G stimulation sites and activate Adenylyl cyclase. The activation of Adenylyl cyclase leads to the production of the second messenger cAMP, which leads to the production of protein kinase A (PKA), which leads to further transcription in the nucleus. D2 to D4 receptors are coupled to G inhibitory sites to inhibit adenylyl cyclase and activate potassium Ion channel. These receptors utilize phosphorylation cascades or direct membrane interactions to affect the functions of voltage-gated and neurotransmitter-gated channels, cytoplasmic enzymes, and transcription factors. Dopamine receptor plays an important role in daily life.

MCE designs a unique collection of 244 small molecules related to dopamine receptor. It is a good tool for screening drugs from nervous system disease.

Chemokines, or chemotactic cytokines, are small cytokines or signaling proteins secreted by cells. They are a component of intercellular communication, controlling the directional movement of immune cells especially leukocytes, as well as other cell types, for instance, endothelial and epithelial cells, which are essential to maintain human health and the function of the immune system.

The biological effects of chemokines are achieved by binding to chemokine receptors, which are G protein-coupled receptors found on the surface of leukocytes. Some chemokine receptors are involved in directing tumor metastasis and over-expression by certain tumors. So inhibiting the interaction between chemokine and chemokine receptors on the surface of tumor cells may be a new possible therapeutic approach. Some chemokine receptors are coreceptors for HIV entry, and related inhibitors have been approved by the FDA to treat patients with HIV. Obviously, chemokines and chemokine receptors have become new targets for studying cancer, HIV, inflammation, and other diseases.

MCE supplies a unique collection of 210 chemokine or chemokine receptor inhibitors and activators, all of which have the identified inhibitory or activated effect on chemokine or chemokine receptors. MCE Chemokine Library is a useful tool for drug research related to cancer, AIDS, and wound therapy.

Drug-induced liver injury (DILI; also known as drug-induced hepatotoxicity) is caused by medications (prescription or OTC), herbal and dietary supplements (HDS), or other xenobiotics that result in abnormalities in liver tests or in hepatic dysfunction that cannot be explained by other causes. Drugs are an important cause of liver injury. Drug-induced hepatic injury is the most common reason cited for withdrawal of an approved drug.

DILI is thought to occur via several different mechanisms. Among these are direct impairment of the structural (e.g., mitochondrial dysfunction) and functional integrity of the liver; production of a metabolite that alters hepatocellular structure and function; production of a reactive drug metabolite that binds to hepatic proteins to produce new antigenic drug-protein adducts, which are targeted by hosts’ defenses (the hapten hypothesis); and initiation of a systemic hypersensitivity response (i.e., drug allergy) that damages the liver.

MCE Drug-induced Liver Injury (DILI) Compound Library contains a unique collection of 1,480 hepatotoxicity causing compounds and is a powerful tool to research DILI and other drug toxicities. This library can be used to understand the mechanisms of DILI, identify biomarkers for early DILI prediction, and allow timely recognition during drug development, thus finally achieving successful DILI prevention and assessment in the pre-marketing phase.

The transforming growth factor beta (TGF-β) signaling pathway is involved in many cellular processes in both the adult organism and the developing embryo including cell growth, cell differentiation, apoptosis, cellular homeostasis and other cellular functions. The TGF-β superfamily comprises TGF-βs, bone morphogenetic proteins (BMPs), activins and related proteins. Signaling begins with the binding of a TGF beta superfamily ligand to a TGF beta type II receptor. The type II receptor is a serine/threonine receptor kinase, which catalyzes the phosphorylation of the Type I receptor. The type I receptor then phosphorylates receptor-regulated SMADs (R-SMADs) which can now bind the coSMAD (e.g. SMAD4). R-SMAD/coSMAD complexes accumulate in the nucleus where they act as transcription factors and participate in the regulation of target gene expression. Deregulation of TGF-β signaling contributes to developmental defects and human diseases, including cancers, some bone diseases, chronic kidney disease, etc.

MCE designs a unique collection of 355 TGF-beta/Smad signaling pathway compounds. TGF-beta/Smad Compound Library acts as a useful tool for TGF-beta/Smad-related drug screening and disease research.

5-HT receptors, also called Serotonin receptors, are a group of G protein-coupled receptors (GPCRs) and ligand-gated ion channels (LGICs) found in the central and peripheral nervous systems. These receptors are now classified into seven families, 5-HT1–7, comprising a total of 14 structurally and pharmacologically distinct mammalian 5-HT receptor subtypes. The 5-HT receptors influence various biological and neurological processes such as aggression, anxiety, appetite, cognition, learning, memory, mood, nausea, sleep, andthermoregulation. The serotonin receptors are the target of a variety of pharmaceutical drugs, including many antidepressants, antipsychotics, anorectics, antiemetics, gastroprokinetic agents, antimigraine agents, hallucinogens, and entactogens.

MCE 5-HT Receptor Compound Library consists of 369 5-HT receptor inhibitors and activators, which can be used for neuropsychiatric disorders drugs discovery.

Neuronal Signaling is involved in the regulation of the mechanisms of the central nervous system (CNS) such as its structure, function, genetics and physiology as well as how this can be applied to understand diseases of the nervous system. Every information processing system in the CNS is composed of neurons and glia, neurons have evolved unique capabilities for intracellular signaling (communication within the cell) and intercellular signaling (communication between cells). G protein-coupled receptors (GPCRs), including 5-HT receptor, histamine receptor, opioid receptor, etc. are the largest class of sensory proteins and are important therapeutic targets in Neuronal Signaling. Besides, Notch signaling, such as β- and γ-secretase, also plays multiple roles in the development of the CNS including regulating neural stem cell (NSC) proliferation, survival, self-renewal and differentiation. GPCR dysfunction caused by receptor mutations and environmental challenges contributes to many neurological diseases. Notch signaling in neurons, glia, and NSCs is also involved in pathological changes that occur in disorders such as stroke, Alzheimer's disease and CNS tumors. Thus, targeting Neuronal Signaling, such as notch signaling and GPCRs, can be used as therapeutic interventions for several different CNS disorders.

MCE designs a unique collection of 3,389 Neuronal Signaling-related compounds that act as a useful tool for the research of neuronal regulation and neuronal diseases.

Ion channels are key proteins on the cell membrane that regulate the flow of ions across membranes. They participate in nearly all physiological processes, including nerve conduction, muscle contraction, heart rhythm, and pain perception. Abnormalities in their function can lead to various serious diseases such as arrhythmia, epilepsy, hypertension, neuropathic pain, and cancer. Therefore, ion channels are highly valuable drug targets—over 15% of approved drugs target ion channels currently, demonstrating their irreplaceable therapeutic value in cardiovascular, neurological, and analgesic fields.

MCE has collected a library of over 5,000 reported ion channel-related bioactive compounds targeting major sites such as Na+ channels, K+ channels, Ca2+ channels, GABA receptors, iGluRs, and others. Using AI models, these compounds are characterized through both 2D representations (molecular fingerprints, pharmacophores) and 3D representations (3D conformation) to screen for a collection of lead-like compounds highly similar to known active molecules. Additionally, an hERG channel prediction algorithm integrating XGB and ISE mapping strategy is employed to assess and exclude potential cardiotoxicity in the library.. This step significantly reduces safety risks in subsequent screenings, particularly for ion channel drug development related to cardiovascular systems (e.g., Nav1.5, Cav1.2), effectively minimizing failures due to hERG inhibition and serving as a valuable tool for ion channel drug screening.

MCE Protein G Agarose, a 4% highly cross-linked agarose reagent coupled with recombinant Protein G, effectively purifies mammalian monoclonal and polyclonal antibodies, such as human IgG3 and rat IgG2a.

MCE IP/Co-IP Kit (Protein A/G Magnetic Beads) can be used for protein purification, IP, Co-IP of target proteins or their protein complexes.

MCE Protein A/G Agarose is an affinity chromatography medium for separation and purification of immunoglobulins.

Protein G Magnetic Beads provide a fast and convenient method for Immunoprecipitation and Co-Immunoprecipitation and Chromatin Immunoprecipitation.

MCE Protein A/G Magnetic Beads provide a fast and convenient method for Immunoprecipitation, Co-Immunoprecipitation and Chromatin Immunoprecipitation.