Abstract: Provided are compositions and methods related to heme transporters and high-throughput methods of identifying agents that can modulate heme transporters. An approach for identifying a modulator of a eukaryotic heme transporter involves adding a toxic heme analog and at least one test agent to a culture of cells, wherein the cells express a recombinant heterologous eukaryotic heme transporter. The cells are incubated with the toxic heme analog and the test agent for a period of time. A change in toxic effect of the toxic heme analog relative to a control is indicative that the test agent is a modulator of the eukaryotic heme transporter. Heme transporter agonists and antagonists can be identified. Also provided is a cell culture comprising a plurality of cells which express a recombinant heterologous eukaryotic heme transporter. The plurality of cells are divided into a plurality of reaction chambers, each of which may contain a test agent, and may further contain a toxic heme analog.

Abstract: Provided are compositions and methods related to heme transporters and high-throughput methods of identifying agents that can modulate heme transporters. An approach for identifying a modulator of a eukaryotic heme transporter involves adding a toxic heme analog and at least one test agent to a culture of cells, wherein the cells express a recombinant heterologous eukaryotic heme transporter. The cells are incubated with the toxic heme analog and the test agent for a period of time. A change in toxic effect of the toxic heme analog relative to a control is indicative that the test agent is a modulator of the eukaryotic heme transporter. Heme transporter agonists and antagonists can be identified. Also provided is a cell culture comprising a plurality of cells which express a recombinant heterologous eukaryotic heme transporter. The plurality of cells are divided into a plurality of reaction chambers, each of which may contain a test agent, and may further contain a toxic heme analog.

Abstract: A functional surface binding specificity of a PAS domain, wherein the PAS domain is predetermined, prefolded in its native state, and comprises a hydrophobic core that has no NMR-apparent a priori formed ligand cavity, is changed by (a) introducing into the hydrophobic core of the PAS domain a foreign ligand of the PAS domain; and (b) detecting a change in the functional surface binding specificity of the PAS domain.

Abstract: Specific binding of a foreign core ligand to a PAS domain, wherein the PAS domain is predetermined, prefolded in its native state, and comprises a hydrophobic core that has no NMR-apparent a priori formed ligand cavity, is determined by (a) detecting a first NMR spectrum of the PAS domain in the presence of a foreign ligand; and (b) comparing the first NMR spectrum with a second NMR spectrum of the PAS domain in the absence of the ligand to infer the presence the ligand specifically bound within the hydrophobic core of the PAS domain. A functional surface binding specificity of a PAS domain, wherein the PAS domain is predetermined, prefolded in its native state, and comprises a hydrophobic core that has no NMR-apparent a priori formed ligand cavity, is changed by (a) introducing into the hydrophobic core of the PAS domain a foreign ligand of the PAS domain; and (b) detecting a change in the functional surface binding specificity of the PAS domain.