| abstract |
(57) [Abstract] [Purpose] Enzyme used in enzyme complementation assay for quantitative analysis of both high molecular weight and low molecular weight (molecular weight 150 to 30,000 dalton) samples with high (10 -15 M) sensitivity. Provided is a recombinant vector having a DNA sequence encoding a donor polypeptide. [Structure] The DNA sequence is properly arranged with an expression control sequence capable of causing replication and expression of the DNA sequence, and the enzyme donor is a reactive group selected from the group consisting of sulfhydryl, amino and carboxyl groups. Wherein the reactive group has no interference either by the interaction of the enzyme donor complex with the enzyme acceptor forming an active enzyme complex or by the competitive binding of the enzyme donor complex to the analyte binding protein and the enzyme acceptor. Recombinant vector having a DNA sequence encoding an enzyme donor polypeptide capable of forming an active enzyme complex having the activity characteristic of β-galactosidase by interaction with an enzyme acceptor, which can be covalently bound to a sample or a sample derivative .. |