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Hepatitis B virus (HBV) infection is a worldwide health problem. More than 400 million people are chronic HBV carriers in the world. Infected individuals are at a high risk of developing liver cirrhosis and hepatocellular carcinoma as the main consequences of HBV. The discoveries of fast diagnostic systems and new therapeutic applications are crucial in the fight against viral hepatitis. In this paper we present the generation of a single-chain variable fragment (scFv) from a mouse monoclonal antibody specific to the HBV surface antigen (HBsAg) and demonstrate its expression as a bacterial alkaline phosphatase (AP) fusion protein. In this study, we constructed scFvs from hybridoma cells expressing HBsAg-specific antibody using phage display technology and expressed them in Escherichia coli. The anti-HBsAg scFvs were inserted into pQE-2 vector to produce scFv antibody genetically fused to bacterial AP. Reproducibility of the recombinant HBsAg-scFv fusion protein was tested using Enzyme-linked Immunosorbent Assay (ELISA). Present preliminary findings indicate that the anti-HBsAg-scFv AP conjugate could be further used for the development of one-step ELISA for the detection of HBV.

Proteases are enzymes that perform important functions in organisms and are used for a variety of objectives in vitro. In recent years, proteases have been used for clinical, pharmaceutical (alimentary digestion, antiinflammatory, etc.) and industrial applications (cheese production, meat tenderizing, leather tanning). In this research, a protease has been purified from primrose (Primula vulgaris) and characterized. Primula vulgaris has been used for medicine since ancient times. The plant grows abundantly in certain regions of Turkey. Ammonium sulphate fractionation and a CM Sephadex column were used for purification of the enzyme. The purification enzyme has an optimum pH = 6.0 and its optimum temperature was 60 degrees C. The v(max) an and Km values determined by Lineweaver-Burk graphics were 6.6 mg/L dak and 0.19 mg/mL respectively. The purification degree and the molecular mass of the enzyme (30 kD alpha) were determined by SDS-PAGE and gel filtration chromatography. It was investigated whether the purified and characterized protease could cause milk to congeal or digest chicken and cow meat. The results show that protease can be used for industrial production.