Shikonin, a natural product from the root of Lithospermum erythrorhizon, is a cytotoxic DNA-binding agent.

To search for compounds that disrupt binding of the EWS-FLI1 fusion protein to its cognate targets, we developed a homogeneous high-throughput proximity assay and screened 5200 small molecule compounds. Many well-known DNA-binding chemotherapeutic agents, such as actinomycin D, cisplatin, doxorubicin, daunorubicin, and epirubicin scored in the assay and not surprising also disrupted the binding of other transcription factors. Unexpectedly, we found that Shikonin, a natural product from the root of Lithospermum erythrorhizon, similarly disrupted protein-DNA interactions.

In silico discovery of androgen receptor antagonists with activity in castration resistant prostate cancer.

Previously available androgen receptor (AR) antagonists (bicalutamide, flutamide, and nilutamide) have limited activity against AR in prostate cancers that relapse after castration [castration resistant prostate cancer (CRPC)]. However, recent AR competitive antagonists such as MDV3100, generated through chemical modifications to the current AR ligands, appear to have increased activity in CRPC and have novel mechanisms of action. Using pharmacophore models and a refined homology model of the antagonist-liganded AR ligand binding domain, we carried out in silico screens of small molecule libraries and report here on the identification of a series of structurally distinct nonsteroidal small molecule competitive AR antagonists.

Small molecule-induced cytosolic activation of protein kinase Akt rescues ischemia-elicited neuronal death.

Elevating Akt activation is an obvious clinical strategy to prevent progressive neuronal death in neurological diseases. However, this endeavor has been hindered because of the lack of specific Akt activators. Here, from a cell-based high-throughput chemical genetic screening, we identified a small molecule SC79 that inhibits Akt membrane translocation, but paradoxically activates Akt in the cytosol.

Solution structure of the guanine nucleotide-binding STAS domain of SLC26-related SulP protein Rv1739c from Mycobacterium tuberculosis.

The structure and intrinsic activities of conserved STAS domains of the ubiquitous SulP/SLC26 anion transporter superfamily have until recently remained unknown. Here we report the heteronuclear, multidimensional NMR spectroscopy solution structure of the STAS domain from the SulP/SLC26 putative anion transporter Rv1739c of Mycobacterium tuberculosis. The 0.

Exploring novel target space: a need to partner high throughput docking and ligand-based similarity searches?

Recent advances in combinatorial chemistry (CC) and High throughput screening (HTS) approaches for use in drug discovery have made it possible to synthesize and/or screen large repositories of chemically diverse scaffolds in search of small molecules that disrupt or regulate macromolecular function. Although successful in the discovery of novel therapeutics this approach is both costly and time consuming. In silico computer aided drug discovery (CADD) approaches including; structure based virtual screening (SBVS) or high throughput docking (HTD) and/or ligand based virtual screening (LBVS) are areas experiencing renewed interest both in the pharmaceutical industry and academia.

Heparin-induced cis- and trans-dimerization modes of the thrombospondin-1 N-terminal domain.

Through its interactions with proteins and proteoglycans, thrombospondin-1 (TSP-1) functions at the interface of the cell membrane and the extracellular matrix to regulate matrix structure and cellular phenotype. We have previously determined the structure of the high affinity heparin-binding domain of TSP-1, designated TSPN-1, in association with the synthetic heparin, Arixtra. To establish that the binding of TSPN-1 to Arixtra is representative of the association with naturally occurring heparins, we have determined the structures of TSPN-1 in complex with heparin oligosaccharides containing eight (dp8) and ten (dp10) subunits, by x-ray crystallography.

Conotoxin therapeutics: a pipeline for success?

The pharmacopoeia of conotoxins from the marine snail Conus has evolved with time, providing a myriad of molecular scaffolds on which critical, molecular pharmacophoric descriptors, responsible for mediating conotoxin receptor-target specificity and selectivity have been grafted. Several reports have defined how these critical determinants contribute to refined, subtype-selective receptor recognition. However, the clinical utility of conotoxins is debatable with a single conotoxin, ω-MVIIA (ziconotide), approved by the US FDA.