Current research in chemical biology最新文献

The family of AURORA kinases is essential for cell cycle progression and dysregulation of AURORA-A in cancer led to a large number of clinical and pre-clinical inhibitors. However, ATP competitive AURORA-A inhibitors usually do not target non-catalytic functions that have also been identified as mechanisms promoting tumorigenesis. To target non-catalytic as well as catalytic functions, we developed a series of PROTACs (PROteolysis TArgeting Chimeras) based on the selective AURORA-A kinase inhibitor MK-5108 (VX-689) and the CEREBLON E3-ligase ligand thalidomide. The most potent PROTAC, JB301, had good physicochemical properties and cell penetration resulting in degradation of AURORA-A in leukemic cells at single digit nM concentration.

Molecular Glues, here defined as small molecules that interact with two protein surfaces to induce or enhance affinity of these two proteins to each other, have received substantial interest as new drug modalities that can unlock otherwise inaccessible pharmacology. The recent serendipitous identification of several new molecular glues suggests that this mode of action is more prevalent than previously thought. However, the identification of molecular glues from scratch and their subsequent optimization still represent a formidable challenge. Here we review the recently discovered molecular glues, general features and insights that can be derived from them as well as from naturally occurring molecular glues, and the implications for drug discovery directed towards molecular glues.

Building on our previous work on ibrutinib-based reversible covalent Bruton's tyrosine kinase (BTK) PROTACs, we explored a different irreversible BTK inhibitor poseltinib as the BTK binder for PROTAC development. Different from ibrutinib, converting the irreversible cysteine reacting acrylamide group of poseltinib to a reversible covalent cyano-acrylamide group dramatically decreases the binding affinity to BTK by over 700 folds. Interestingly, one of the reversible covalent BTK PROTACs based on poseltinib with a rigid linker, dubbed as PS-RC-1, is highly potent (IC₅₀ ​= ​∼10 ​nM) in Mino cells but not in other mantle cell lymphoma (MCL) cell lines, such as Jeko-1 and Rec-R cells. We showed that PS-RC-1 potently induces degradation of IKZF1 and IKZF3 but not BTK or GSPT1, accounting for its toxicity in Mino cells. We further decreased the molecular size of PS-RC-1 by shrinking the BTK binding moiety and developed PS-2 as a potent BTK and IKZF1/3 triple degrader with high specificity.

Photoenzymes are potentially attractive biocatalysts for chemicals synthesis and biomanufacturing. They do not require coenzymes such as NAD(P)H, or high energy molecules like ATP, and their activity can be controlled precisely in a temporal and spatial manner by light. The light-activated fatty acid photodecarboxylase (FAP) was discovered in 2017. Since its discovery, biophysical, structural, and computational methods have been used to understand how FAP uses blue light to catalyze the decarboxylation of fatty acid substrates. As a natural photobiocatalyst, FAP could offer insights into the design of new photoenzymes. Here, we provide a perspective on the structure, mechanism and biotechnological applications of FAP enzymes, and understanding from which new photobiocatalysts could be developed. We review early success in the engineering of FAPs but also identify major challenges for wider use of this recently discovered enzyme family in biotechnology and the chemical sciences. Based on these early insights, the reader is invited to consider if the use of FAPs will continue to flourish, or whether current limitations signify a false dawn.

Off-target binding is one of the primary causes of toxic side effects of drugs in clinical development, resulting in failures of clinical trials. While off-target drug binding is a known phenomenon, experimental identification of the undesired protein binders can be prohibitively expensive due to the large pool of possible biological targets. Here, we propose a new strategy combining chemical similarity principle and deep learning to enable proteome-wide mapping of compound-protein interactions. We have developed a pipeline to identify the targets of bioactive molecules by matching them with chemically similar annotated “bait” compounds and ranking them with deep learning. We have constructed a user-friendly web server for drug-target identification based on chemical similarity (DRIFT) to perform searches across annotated bioactive compound datasets, thus enabling high-throughput, multi-ligand target identification, as well as chemical fragmentation of target-binding moieties.

Viral diseases are prominent among the widely spread infections threatening human well-being. Real-life clinical successes of the few available therapeutics are challenged by pathogenic resistance and suboptimal delivery to target sites. Nanotechnology has aided the design of functionalised and non-functionalised Au and Ag nanobiomaterials through physical, chemical and biological (green synthesis) methods with improved antiviral efficacy and delivery. In this review, innovative designs as well as interesting antiviral activities of the nanotechnology-inclined biomaterials of Au and Ag, reported in the last 5 years were critically overviewed against several viral diseases affecting man. These include influenza, respiratory syncytial, adenovirus, severe acute respiratory syndromes (SARS), rotavirus, norovirus, measles, chikungunya, HIV, herpes simplex virus, dengue, polio, enterovirus and rift valley fever virus. Notably identified among the nanotechnologically designed promising antiviral agents include AuNP-M2e peptide vaccine, AgNP of cinnamon bark extract and AgNP of oseltamivir for influenza, PVP coated AgNP for RSV, PVP-AgNPs for SARS-CoV-2, AuNRs of a peptide pregnancy-induced hypertension and AuNP nanocarriers of antigen for MERS-CoV and SARS-CoV respectively. Others are AgNPs of collagen and Bacillus subtilis for rotavirus, AgNPs labelled Ag30–SiO₂ for murine norovirus in water, AuNPs of Allium sativum and AgNPs of ribavirin for measles, AgNPs of Citrus limetta and Andrographis Paniculata for Chikungunya, AuNPs of efavirenz and stavudine, and AgNPs-curcumin for HIV, NPAuG3-S8 for HSV, AgNPs of Moringa oleifera and Bruguiera cylindrica for dengue while AgNPs of polyethyleneimine and siRNA analogues displayed potency against enterovirus. The highlighted candidates are recommended for further translational studies towards antiviral therapeutic designs.

Co-localising enzymes can drastically affect their properties, such as stability, specificity, and activity, thus influencing reaction kinetics. In this review, we present a brief overview of the main methods developed for enzyme immobilisation, co-localisation, and conjugation and discuss how and why they affect the enzyme properties. We also describe the effects emerging from bringing two sequential enzymes of a cascade reaction together, particularly if and when it speeds up reaction velocity. Furthermore, we discuss enzyme compartmentalisation, or clustering of several enzymes of a cascade, and present theoretical approaches developed to optimise synthetic enzyme clusters. We also point out the plenitude of open questions, which exist despite the enormous research effort channelled into understanding enzyme co-localisation.

Human Dihydroorotate dehydrogenase, which catalyses de novo pyrimidine biosynthesis, is an emerging target for treatment of infectious diseases, arthritis and cancer. In order to provide a chemical tool studying this key enzyme, we characterized IPP/CNRS-A017, a highly potent, selective, and cell-active inhibitor of the human Dihydroorotate dehydrogenase (hDHODH). In this report, we describe the crystal structure of IPP/CNRS-A017 in complex with hDHODH, providing inside into its binding mode. Additionally, further off-target profiling in a kinome-wide screen and a G-Protein-Coupled Receptors screen as well as investigated cell viability effects in three different cell lines (HEK293T, U2OS, human fibroblasts) confirmed that IPP/CNRS-A017 is a highly selective chemical tool to study the biology of hDHODH. Specific sensitivity to IPP/CNRS-A017 was observed in patient-derived colorectal cancer organoids.

Glycogen phosphorylase kinase (PhK) converts by phosphorylation, the inactive glycogen phosphorylase (GPb) into active GPa in the glycogenolytic pathway. It is a complex enzyme comprising of the catalytic (γ) and three regulatory subunits (α, β, δ) forming a hexadecamer with stoichiometry (αβγδ)_4. Several studies have indicated PhK as a promising target for the development of antihyperglycemics as its inhibition blocks glycogenolysis in liver and a potential therapeutic target for cancer against pathological angiogenesis and tumor progression. The identification of compounds that inhibit the kinase through their direct binding to its catalytic site is an effective approach to identify bioactive molecules of therapeutic significance. Towards this, the structure of the N-terminal kinase domain (residues 1–298) of the catalytic γ subunit of PhK (PhKγtrnc) has been determined by X-ray crystallography while staurosporine and indirubin analogues have been characterized as potent inhibitors targeting the ATP binding site. In this study, a series of 38 synthetic analogues of naturally occurring coumarins were screened for inhibition of PhKγtrnc, in vitro, using a photometric assay. The IC₅₀ values of the two most potent compounds were determined for PhKγtrnc and the pharmacologically relevant target, human liver isoform (PHKG2A). Their cellular efficacy and toxicity in HepG2 cells were further assessed ex vivo. Docking experiments and the structural comparison with previously described inhibitors reveal the binding mode of the coumarin scaffold at a no hinge region of the ATP site of PhK and the role of a conserved β3-Lys in binding. The experimental findings provide structural insights with implications to the kinase targeting and drug design.