TRIVALENT METAL MEDIATED HOMOGENEOUS LUMINESCENT PROXIMITY ASSAY

摘要

An in vitro protein kinase assay technology that (1) exhibits a high assay signal to background ratio (S/B) and range (S-B); (2) is homogenous; (3) is non-radioactive; and (4) does not require a phospho-specific antibody. Said assay involves complexing a trivalent metal ion (e.g. Ga3+ , Fe3+ , Al3+ , In3+ , Ru3+ , Sc3+ , Y3+) to the surface of amplified luminescent proximity assay acceptor or donor beads, e.g., via a suitable linker such as nitrilotriacetic acid (NTA; also referred to as carboxymethyl-lysine), iminodiacetic acid (IDA), or an appropriately substituted N-containing heterocycle, for example a triazoheterocycle, for example a triazocyclononaneononane, such as 1-propylamino-4-acetato-1,4,7-triazacyclononane. A protein (or constituent part) or other kinase substrate is bound to the surface of the other of an amplified luminescent proximity assay acceptor or donor bead and, if phosphory-lated, brought into proximity with the trivalent metal ion-complexed acceptor bead to generate a luminescent signal. Presence of a kinase inhibitor inhibits phosphorylation and therefore signal generation and, in this way, is detectable. As the invention described herein recognizes the presence or absence of phosphate groups on a protein, (or constituent part), or other biological macromolecule (e.g., mono, di, or trinucleotides, cyclic nucleotides or phosphate substituted inositols), it is broadly applicable to any phosphorly-lation or dephosphorylation reaction enzymes and provides a highly robust and flexible assay format for protein kinases and other enzyme classes, including lipid kinases, phosphatases, phosphodiesterases and others.