Bacteriophage gene 3 protein compositions and use as amyloid binding agents

A method of detecting or imaging an amyloid aggregate in a biological sample comprising

• a) exposing the biological sample to a composition comprising a detectable label attached to an amyloid binding polypeptide or to a fusion protein comprising the amyloid binding polypeptide;
• and
• b) detecting or imaging any labeled polypeptide-amyloid conjugate, wherein the amyloid binding polypeptide comprises:
• a wild type g3p,
• an amyloid binding fragment of wild type g3p, or
• a mutant or variant g3p that is at least 90% identical to
• (i) SEQ ID NO:1, or
• (ii) an amyloid binding fragment of SEQ ID NO:1;
• wherein the amyloid binding polypeptide does not comprise bacteriophage.

A method for diagnosing a disease or disorder associated with amyloid in a patient comprising the steps of:

• a) administering to the patient an imaging agent comprising
• a detectable label attached to an amyloid binding polypeptide or
• a fusion protein comprising an amyloid binding polypeptide;
• b) allowing the agent to bind to any amyloid that is present;
• and
• c) detecting any imaging agent that has bound to amyloid,
• wherein the amyloid binding polypeptide comprises:
• a wild type g3p,
• an amyloid binding fragment of wild type g3p, or
• a mutant or variant g3p that is at least 90% identical to SEQ ID NO:1 or at
• least 90% identical to an amyloid binding fragment SEQ ID NO:1, and wherein the amyloid binding polypeptide does not comprise bacteriophage.