Method for controlling protein dimerization using an intramolecular to intermolecular conformational switch

A method of analyte detection comprising:

• mixing a sample containing an analyte with a test solution;
• and
• detecting a signal, and
• wherein the test solution comprises:
• a first polypeptide comprising a first and second alpha helix forming amino acid sequences configured to form a first intramolecular coiled coil when bound, a first subunit of a split enzyme, and an analyte binding component;
• and
• a second polypeptide comprising a third and fourth alpha helix forming amino acid sequences configured to form a second intramolecular coiled coil when bound, and a second subunit of a split enzyme,
• wherein the first and third alpha helix forming amino acid sequences are configured to form a first intermolecular coiled coil when the first intramolecular coiled coil is not formed and the second and fourth alpha helix forming amino acid sequences are configured to form a second intermolecular coiled coil when the second intramolecular coiled coil is not formed,
• wherein each of the first and second intermolecular coiled coils are more energetically favorable than each of the first and second intramolecular coiled coils,
• wherein the first, second, third, and fourth alpha helix forming amino acid sequences are different, and
• wherein the first and second subunits of the split enzyme are configured to generate a signal when bound.