Methods for target molecule detection using siderophores and related compositions

A method for determining the presence of a target molecule in a sample, comprising:

• (a) contacting a sample with a capture agent, the agent comprising a siderophore and a transition metal cation, under conditions wherein the agent is capable of binding a target molecule to form a target molecule-capture agent complex, wherein the target molecule is selected from the group consisting of a phosphorylated molecule, a nitrotyrosine-containing molecule and a sulfated molecule, and
• (b) detecting formation of a target molecule-capture agent complex, thereby determining the presence of the target molecule in the sample.

A method for isolating a phosphorylated histidine containing molecule from a sample, comprising:

• (a) contacting a sample with a capture agent, the agent comprising a siderophore and copper (II) cation, under conditions wherein the agent is capable of binding a phosphorylated molecule to form a phosphorylated histidine containing molecule-capture agent complex, and
• (b) separating the phosphorylated histidine containing molecule-capture agent complex from the sample, thereby isolating the phosphorylated histidine containing molecule from the sample.

A commercial package, comprising an isolated siderophore and a transition metal salt.

A commercial package, comprising an isolated siderophore and a transition metal solution.

A method for identifying a capture agent, comprising:

• a. contacting a siderophore-transition metal cation-complex with a phosphorylated moiety, and
• b. determining the ability of the complex to bind to the phosphorylated moiety, thereby identifying a capture agent.

A composition, comprising a desferrioxamine complexed with a gallium (III) cation.