Fingerprint signatures of lanthanide circularly polarized luminescence from proteins covalently labeled with a β-diketonate europium(III) chelate.

Fingerprint signatures of circularly polarized luminescence (CPL) are observed from Staphylococcus aureus nuclease (SNase), bovine serum albumin (BSA), and insulin (Ins) labeled with europium(III) complexes containing a β-diketonate ligand, where SNase shows a virtually opposite CPL sign compared to those of BSA and Ins.

Systematic alanine insertion reveals the essential regions that encode structure formation and activity of dihydrofolate reductase.

Decoding sequence information is equivalent to elucidating the design principles of proteins. For this purpose, we conducted systematic alanine insertion analysis to reveal the regions in the primary structure where the sequence continuity cannot be disrupted. We applied this method to dihydrofolate reductase (DHFR), and examined the effects of alanine insertion on structure and the enzymatic activity by solubility assay and trimethoprim resistance, respectively.