Detection of molecular interactions by β-lactamase reporter fragment complementation

A method of screening for binding of a first binding moiety with members of a plurality of different second putative binding moieties in a eukaryotic cell, the method comprising:

• a) providing a plurality of beta-lactamase enzyme complementation reporter systems each comprising:
• a first component comprising a first beta-lactamase enzyme fragment coupled to the first binding moiety wherein the first beta-lactamase enzyme fragment is about 19 kDa in size;
• and
• a second component comprising a second beta-lactamase enzyme fragment coupled to one of said plurality of different second putative binding moieties wherein the second beta-lactamase enzyme fragment is about 10 kDa in size;
• wherein the first beta-lactamase enzyme fragment and the second beta-lactamase enzyme fragment are complementing beta-lactamase enzyme fragments, wherein beta-lactamase enzyme complementation occurs when the first binding moiety and one of said different second putative binding moieties bind to one another;
• b) combining the first component and the second component of each of the plurality of beta-lactamase enzyme complementation reporter systems in a corresponding plurality eukaryotic cells, wherein each of the corresponding plurality of eukaryotic cells includes the first component and a corresponding different one of the second components, wherein the first component is in each of the corresponding plurality of eukaryotic cells;
• and
• c) detecting beta-lactamase enzyme complementation in each of the corresponding plurality of eukaryotic cells, wherein detection of beta-lactamase enzyme complementation and resultant beta-lactamase enzymatic activity in one of the corresponding plurality of eukaryotic cells indicates binding of the first binding moiety with the second putative binding moiety of the corresponding second component in the eukaryotic cell.