Biomedical subjects

Marina Veronesi

Publications and source records attributed to Marina Veronesi.

5 recordsLinked to original sources

PubMed2003

A general NMR method for rapid, efficient, and reliable biochemical screening.

High-throughput screening is usually the method of drug-lead discovery. It is now well accepted that, for a functional assay, quality is more important than quantity. The ligand-based or protein-based NMR screening methodologies for detecting compounds binding to the macromolecular target of interest are now well established. A novel and sensitive NMR method for rapid, efficient, and reliable biochemical screening is presented. The method named 3-FABS (three fluorine atoms for biochemical screening) requires the labeling of the substrate with a CF(3) moiety and utilizes (19)F NMR spectroscopy for the detection of the starting and enzymatically modified substrates. The method allows for high-quality screening of large compound or natural product extract collections and for measuring their IC(50) values. Applications of this technique to the screening of inhibitors of the Ser/Thr kinase AKT1 and the protease trypsin are presented. In addition, an interesting application of 3-FABS to functional genomics is also presented.

Enzyme Inhibitors↗

PubMed2002

High-throughput NMR-based screening with competition binding experiments.

The Achilles heel of ligand-based NMR screening methods is their failure to detect high-affinity ligands and molecules that bind covalently to the receptor. We have developed a novel approach for performing high-throughput screening with NMR spectroscopy that overcomes this limitation. The method also permits detection of potential high-affinity molecules that are only marginally soluble, thus significantly enlarging the diversity of compounds amenable to NMR screening. The techniques developed utilize transverse and/or selective longitudinal relaxation parameters in combination with competition binding experiments. Mathematical expressions are derived for proper setup of the NMR experiments and for extracting an approximate value of the binding constant for the identified ligand from a single-point measurement. With this approach it is possible to screen thousands of compounds in a short period of time against protein or DNA and RNA fragments. The methodology can also be applied for screening plant and fungi extracts.

Binding, Competitive↗

PubMed2002

NMR-Based screening with competition water-ligand observed via gradient spectroscopy experiments: detection of high-affinity ligands.

Water-ligand observed via gradient spectroscopy (WaterLOGSY) represents a powerful method for primary NMR screening in the identification of compounds interacting with macromolecules, including proteins and DNA or RNA fragments. The method is useful for the detection of compounds binding to a receptor with binding affinity in the micromolar range. The Achille's heel of the method, as with all the techniques that detect the ligand resonances, is its inability to identify strong ligands with slow dissociation rates. We show here that the use of a reference compound with a known K(D) in the micromolar range together with properly designed competition binding experiments (c-WaterLOGSY) permits the detection of strong binders. A derived mathematical expression is used for the selection of the appropriate setup NMR experimental conditions and for an approximate determination of the binding constant. The experiment requires low ligand concentration, therefore allowing its application in the identification of potential strong inhibitors that are only marginally soluble. The technique is particularly suitable for rapid screening of chemical mixtures and plant or fungi extracts.

Algorithms↗

PubMed2002

Competition binding experiments for rapidly ranking lead molecules for their binding affinity to human serum albumin.

Many lead molecules that have high affinity for a therapeutic target in vitro exhibit a reduced efficacy in vivo. Drug binding to human serum albumin is a major contributor to this reduction in potency, and many drug discovery programs expand significant resources preparing compounds that have decreased albumin binding. As rational and structure-based approaches have already been demonstrated to design compounds that have reduced affinity for albumin, the ability to rapidly and accurately assess protein binding will be valuable in lead optimization. This review will summarize some of the NMR-based efforts towards developing universal, rapid, accurate, and site-specific assays for estimating protein binding.

Binding Sites↗

PubMed2002

Fluorine-NMR competition binding experiments for high-throughput screening of large compound mixtures.

High-throughput ligand-based NMR screening with competition binding experiments is extended to (19)F detection. Fluorine is a favorable nucleus for these experiments because of the significant contribution of the Chemical Shift Anisotropy (CSA) to the (19)F transverse relaxation of the ligand signal when bound to a macromolecular target. A low to moderate affinity ligand containing a fluorine atom is used as a reference molecule for the detection and characterization of new ligands. Titration NMR experiments with the selected reference compound are performed for finding the optimal set-up conditions for HTS and for deriving the binding constants of the identified NMR hits. Rapid HTS of large chemical mixtures and plant or fungi extracts against the receptor of interest is possible due to the high sensitivity of the (19)F nucleus and the absence of overlap with the signals of the mixtures to be screened. Finally, a novel approach for HTS using a reference molecule in combination with a control molecule is presented.

Anisotropy↗