Kinetic profiling of novel spirobenzo-oxazinepiperidinone derivatives as equilibrative nucleoside transporter 1 inhibitors.

Evaluation of kinetic parameters of drug-target binding, k, k, and residence time (RT), in addition to the traditional in vitro parameter of affinity is receiving increasing attention in the early stages of drug discovery. Target binding kinetics emerges as a meaningful concept for the evaluation of a ligand's duration of action and more generally drug efficacy and safety. We report the biological evaluation of a novel series of spirobenzo-oxazinepiperidinone derivatives as inhibitors of the human equilibrative nucleoside transporter 1 (hENT1, SLC29A1).

Molecular Basis of Ligand Dissociation from G Protein-Coupled Receptors and Predicting Residence Time.

G protein-coupled receptors (GPCRs) are integral membrane proteins and represent the largest class of drug targets. During the past decades progress in structural biology has enabled the crystallographic elucidation of the architecture of these important macromolecules. It also provided atomic-level visualization of ligand-receptor interactions, dramatically boosting the impact of structure-based approaches in drug discovery.

A covalent antagonist for the human adenosine A receptor.

The structure of the human A adenosine receptor has been elucidated by X-ray crystallography with a high affinity non-xanthine antagonist, ZM241385, bound to it. This template molecule served as a starting point for the incorporation of reactive moieties that cause the ligand to covalently bind to the receptor. In particular, we incorporated a fluorosulfonyl moiety onto ZM241385, which yielded LUF7445 (4-((3-((7-amino-2-(furan-2-yl)-[1, 2, 4]triazolo[1,5-a][1, 3, 5]triazin-5-yl)amino)propyl)carbamoyl)benzene sulfonyl fluoride).

In search of novel ligands using a structure-based approach: a case study on the adenosine A receptor.

In this work, we present a case study to explore the challenges associated with finding novel molecules for a receptor that has been studied in depth and has a wealth of chemical information available. Specifically, we apply a previously described protocol that incorporates explicit water molecules in the ligand binding site to prospectively screen over 2.5 million drug-like and lead-like compounds from the commercially available eMolecules database in search of novel binders to the adenosine A receptor (AAR).

Scintillation proximity assay (SPA) as a new approach to determine a ligand's kinetic profile. A case in point for the adenosine A1 receptor.

Scintillation proximity assay (SPA) is a radio-isotopic technology format used to measure a wide range of biological interactions, including drug-target binding affinity studies. The assay is homogeneous in nature, as it relies on a "mix and measure" format. It does not involve a filtration step to separate bound from free ligand as is the case in a traditional receptor-binding assay.

The Role of Target Binding Kinetics in Drug Discovery.

Traditionally structure-activity/affinity relationships (SAR) have dominated research in medicinal chemistry. However, structure-kinetics relationships (SKR) can be very informative too. In this viewpoint we explore the molecular determinants of binding kinetics and discuss challenges for future binding kinetics studies.

Mass spectrometry-based ligand binding assays on adenosine A1 and A2A receptors.

Conventional methods to measure ligand-receptor binding parameters typically require radiolabeled ligands as probes. Despite the robustness of radioligand binding assays, they carry inherent disadvantages in terms of safety precautions, expensive synthesis, special lab requirements, and waste disposal. Mass spectrometry (MS) is a method that can selectively detect ligands without the need of a label.

Evaluation of (4-Arylpiperidin-1-yl)cyclopentanecarboxamides As High-Affinity and Long-Residence-Time Antagonists for the CCR2 Receptor.

Animal models suggest that the chemokine ligand 2/CC-chemokine receptor 2 (CCL2/CCR2) axis plays an important role in the development of inflammatory diseases. However, CCR2 antagonists have failed in clinical trials because of a lack of efficacy. We previously described a new approach for the design of CCR2 antagonists by the use of structure-kinetics relationships (SKRs).

Allosteric modulation of G protein-coupled receptors.

Allosteric modulation of G protein-coupled receptors is a relatively novel and unexplored pharmacological concept that may lead to more selective and more 'natural' drugs for these receptors. In particular, allosteric enhancers may serve as tools to intensify selectively a weakened hormone or neurotransmitter signal caused by a localized deficit, such as in Alzheimer's or Parkinson's disease. In this paper, attention is paid to the adenosine A1 receptor, for which novel allosteric enhancers were synthesized and characterized that proved superior to the prototypic allosteric enhancer PD 81,723.