Hybrid Minimal Core Streptavidin-Obelin as a Versatile Reporter for Bioluminescence-based Bioassay.

Ca2+ -regulated photoprotein obelin was genetically fused with a minimum-sized core streptavidin. Hybrid protein (SAV-OL) was produced by bacterial expression and applied as a specific bioluminescent probe in diverse solid-phase assays. The obtained results clearly demonstrate specific activity of each domain indicating its proper folding with favorable space orientation. SAV-OL has been shown to be a much more sensitive label than the chemical conjugate of a full-length streptavidin with obelin.