Site-directed ligand discovery.

Article Details

Citation

Erlanson DA, Braisted AC, Raphael DR, Randal M, Stroud RM, Gordon EM, Wells JA

Site-directed ligand discovery.

Proc Natl Acad Sci U S A. 2000 Aug 15;97(17):9367-72.

PubMed ID
10944209 [ View in PubMed
]
Abstract

We report a strategy (called "tethering") to discover low molecular weight ligands ( approximately 250 Da) that bind weakly to targeted sites on proteins through an intermediary disulfide tether. A native or engineered cysteine in a protein is allowed to react reversibly with a small library of disulfide-containing molecules ( approximately 1,200 compounds) at concentrations typically used in drug screening (10 to 200 microM). The cysteine-captured ligands, which are readily identified by MS, are among the most stable complexes, even though in the absence of the covalent tether the ligands may bind very weakly. This method was applied to generate a potent inhibitor for thymidylate synthase, an essential enzyme in pyrimidine metabolism with therapeutic applications in cancer and infectious diseases. The affinity of the untethered ligand (K(i) approximately 1 mM) was improved 3,000-fold by synthesis of a small set of analogs with the aid of crystallographic structures of the tethered complex. Such site-directed ligand discovery allows one to nucleate drug design from a spatially targeted lead fragment.

DrugBank Data that Cites this Article

Polypeptides
NameUniProt ID
Thymidylate synthaseP0A884Details