EXPRESSION OF A BIFUNCTIONAL CHIMERIC PROTEIN-A - VARGULA HILGENDORFII LUCIFERASE IN MAMMALIAN-CELLS

We have designed and constructed a novel chimeric protein that consist ed of a single domain of protein A and luciferase derived from sea-fir efly Vargula hilgendorfii with the goal of obtaining a heterofunctiona l immunological tool. The structural gene of luciferase was fused to t he 3' terminus of the D domain gene of protein A with/without a short linker of five amino acids. The resulting constructs under the transcr iptional regulation of the Rous sarcoma virus (RSV) promoter; were exp ressed transiently in simian COS-1 and stably in Chinese hamster ovary (CHO) cells. The properties of the the resultant chimeric protein wer e characterized. The results indicated that the dual properties of the chimeric protein could be retained only after the introduction of a l inker of (Gly)(4) Ser between the two conjugated moieties. Moreover th e chimeric protein was found to retain at least 50% of the specific ac tivity as compared with the non-fused luciferase. The future prospect of the usage of this chimeric protein in the field of diagnostics was further evaluated by performing bioluminescent immunoassays.