Apoptosis proteins

Protein ubiquitination is an enzymatic post-translational modification in which an ubiquitin protein is attached to a substrate protein. Ubiquitination involves three main steps: activation, conjugation, and ligation, performed by ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s), and ubiquitin ligases (E3s), respectively. Ubiquitination affects cellular processes such as apoptosis, cell cycle, DNA damage repair, and membrane transportation, etc. by regulating the degradation of proteins (via the proteasome and lysosome), altering the cellular localization of proteins, affecting proteins activity, and promoting or preventing protein-protein interactions. Deregulation of ubiquitin pathway leads to many diseases such as neurodegeneration, cancer, infection and immunity, etc.

MCE offers a unique collection of 269 small molecule modulators with biological activity used for ubiquitination research. Compounds in this library target the key enzymes in ubiquitin pathway. MCE Ubiquitination Compound Library is a useful tool for the research of ubiquitination regulation and the corresponding diseases.

Protein serine/threonine kinases (PSKs) are protein kinases that use ATP as a high-energy donor molecule to transfer phosphate groups to serine/threonine residues of target protein. As an important signal transduction regulator, serine/threonine kinases can affect the function of target proteins by disrupting enzyme activity or binding of target proteins to other proteins. Serine/threonine kinases are involved in the regulation of immune response, cell proliferation, differentiation, apoptosis and other physiological processes. Serine/threonine kinase inhibitors are an important class of compounds that have been widely studied in cancer, chronic inflammation, autoimmune diseases, aging and other diseases.

MCE designs a unique collection of 1,360 serine/threonine kinase inhibitors, mainly targeting the receptor PKA, Akt, PKC, MAPK/ERK, etc, which is an effective tool for development and research of anti-cancer, anti-chronic inflammatory diseases, anti-autoimmune diseases and anti-aging compounds.

Proteolysis-targeting chimera (PROTAC) has been developed to be a useful technology for targeted protein degradation. PROTACs consist of a ligand for E3 ligase (E3 ligase binder), a linker and a ligand (mostly small-molecule inhibitor) for protein of interest（target binder）. Upon binding to the target protein, the PROTACs can recruit E3 for target protein ubiquitination, which is subjected to proteasome-mediated degradation.

Although there are more than 600 E3 ubiquitin ligases, only several with small molecule ligands have been used for designing PROTACs, including Skp1-Cullin-F box complex containing Hrt1 (SCF), Von Hippel-Lindau tumor suppressor (VHL), Cereblon (CRBN), inhibitor of apoptosis proteins (IAPs), and mouse double minute 2 homolog (MDM2).

MCE carefully prepared a unique collection of 57 ligands for E3 ligase, which have been reported to be used in PROTAC design. MCE E3 ligase ligand library is a useful tool for PROTAC development.

Copper is an important co-factor of all biological enzymes, but if the concentration exceeds the threshold of maintaining the homeostasis mechanism, copper will lead to cytotoxicity. This death mechanism has been named "Cuproptosis".

The mechanism of cuproptosis distinct from all other known mechanisms of regulated cell death, including apoptosis, pyroptosis, necroptosis, and ferroptosis.

Copper combine with the lipoylated components of the tricarboxylic acid cycle (TCA), leading to lipoylated protein aggregation and subsequent loss of iron-sulfur cluster proteins, ultimately resulting in protein toxicity stress and cell death. Studies have shown that the necessary factors for cuproptosis include the presence of glutathione, mitochondrial metabolism of galactose and pyruvate, and glutamine metabolism.

Targeted regulation of cuproptosis is a potential choice to treat cancer, rheumatoid arthritis, and other diseases. For example, up-regulation of LIPT1 may inhibit the occurrence and development of tumors by destroying TCA in mitochondria and then inducing cuproptosis.

MCE supplies a unique collection of 217 cuproptosis-related compounds, all of which act on the targets or signaling pathways related to cuproptosis and may have in inhibitory or activated effect on cuproptosis. MCE Cuproptosis Library is a useful tool for drug research related to cancer, rheumatoid arthritis, and other diseases.

The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway is central to signaling by cytokine receptors, a superfamily of more than 30 transmembrane proteins that recognize specific cytokines, and is critical in blood formation and immune response. Canonical JAK/STAT signaling begins with the association of cytokines and their corresponding transmembrane receptors. Activated JAKs then phosphorylate latent STAT monomers, leading to dimerization, nuclear translocation, and DNA binding. In mammals, there are four JAKs (JAK1, JAK2, JAK3, TYK2) and seven STATs (STAT1, STAT2, STAT3, STAT4, STAT5a, STAT5b, STAT6). Since the JAK/STAT pathway plays a major role in many fundamental processes, such as apoptosis and inflammation, dysfunctional proteins in the pathway may lead to a number of diseases. For example, alterations in JAK/STAT signalling can result in cancer and diseases affecting the immune system, such as severe combined immunodeficiency disorder (SCID).

MCE provides 464 compounds that can be used in the study of the JAK/STAT signaling pathway and related diseases.

With the progress of modern cancer therapy, the life of cancer patients has been extended. However, after initial treatment and recovery, the development of secondary tumors often leads to cancer recurrence. Cancer stem cells are a small number of cells that tumor growth and reproduction depend on.

Cancer stem cells have strong self-renewal ability, which is the direct cause of tumor occurrence. In addition, cancer stem cells also have the ability to differentiate into different cell types, playing a crucial role in tumor metastasis and development. Chemotherapy and radiotherapy induced DNA damage and apoptosis are common cancer treatments. However, cancer stem cells can effectively protect cancer cells from apoptosis by activating DNA repair ability. Cancer stem cells are regarded as the key "seed" of tumor occurrence, development, metastasis and recurrence. Since its first discovery in leukemia in 1994, cancer stem cells have been considered a promising therapeutic target for cancer treatment.

MCE supplies a unique collection of 2,284 compounds targeting key proteins in cancer stem cells. MCE Cancer Stem Cells Compound Library is a useful tool for cancer stem cells related research and anti-cancer drug development.

Programmed cell death pathways, including apoptosis, pyroptosis and necroptosis, are regulated by unique sets of host proteins that coordinate a variety of biological outcomes. Pyroptosis is a highly inflammatory form of programmed cell death that occurs most frequently upon infection with intracellular pathogens and is likely to form part of the antimicrobial response. This process promotes the rapid clearance of various bacterial, viral, fungal and protozoan infections by removing intracellular replication niches and enhancing the host's defensive responses. Pyroptosis has been widely studied in inflammatory and infection disease models. Recently, there are growing evidences that pyroptosis also plays an important role in the development of cancer, cardiovascular diseases and Metabolic disorder, etc.

MCE designs a unique collection of 1,352 pyroptosis-related compounds mainly focusing on the key targets in the pyroptosis signaling pathway and can be used in the research of pyroptosis signal pathway and related diseases.

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 243 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.

MAPK families play an important role in complex cellular programs like proliferation, differentiation, development, transformation, and apoptosis. In mammalian cells, four MAPK families have been clearly characterized: ERK1/2, C-Jun N-terminal kinse/stress-activated protein kinase (JNK/SAPK) , p38 kinase and ERK5. They respond to different signals. Each MAPK-related cascade consists of three enzymes that are activated in series: a MAPK kinase kinase (MAPKKK), a MAPK kinase (MAPKK) and a MAP kinase (MAPK). MAPK signaling pathways has been implicated in the development of many human diseases including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and various types of cancers.

MCE designs a unique collection of 560 MAPK signaling pathway inhibitors that act as a useful tool for MAPK-related drug screening and disease research.

The PI3K/Akt/mTOR pathway controls many cellular processes that are important for the formation and progression of cancer, including apoptosis, transcription, translation, metabolism, angiogenesis, and cell cycle progression. Every major node of this signaling network is activated in a wide range of human tumors. Mechanisms for the pathway activation include activation of receptor tyrosine kinases (RTKs) upstream of PI3K, mutation or amplification of PIK3CA encoding p110α catalytic subunit of PI3K, mutation or loss of PTEN tumor suppressor gene, and mutation or amplification of Akt1. Once the pathway is activated, signaling through Akt can stimulate a series of substrates including mTOR which is involved in protein synthesis. Thus, inhibition of this pathway is an attractive concept for cancer prevention and/or therapy. Currently some mTOR inhibitors are approved for several indications, and there are several novel PI3K/Akt/mTOR inhibitors in clinical trials.

MCE owns a unique collection of 613 compounds that can be used for PI3K/Akt/mTOR pathway research. PI3K/Akt/mTOR Compound Library also acts as a useful tool for anti-cancer drug discovery.