[2P-2] Poster 2 (2P-38ー2P-88)

[2P-85*] Construction of an Artificial Protein Dimer for Selective Binding Biomolecule at Its Interface

^○Hiroaki Inaba¹, Yuma Shisaka¹, Garyo Ueda¹, Kazuto Suzuki¹, Shinya Ariyasu¹, Yuichiro Aiba¹, Hiroshi Sugimoto^2,3, Osami Shoji^1,2 (1.Dept. of Chem., Grad. Sch. of Sci., Nagoya Univ., 2.JST CREST, 3.RIKEN SPring-8 Center)

Heme substitution is one of the most powerful methods to control the function of heme proteins. Generally, the structures of the incorporated synthetic complexes are limited to those like heme. However, heme acquisition system protein A (HasA) can capture various synthetic complexes other than heme such as Ga-phthalocyanine because of its unique fashion of heme binding. Recently, we have found that HasA can capture Fe-tetraphenylporphyrin (Fe-TPP) and its phenyl groups are exposed to the solvent. Based on this knowledge, we anticipated that some function unit can be linked to the phenyl group. Therefore, we designed HasA dimer using metal coordination site linked with the phenyl group of Fe-TPP. This design regulates distance and movement of HasA dimer owing to the rigidity of its porphyrin and coordination site structure. The resulting HasA dimer can be expected to recognize biomolecules by its interface. We synthesized Fe-TPP with phenanthroline as coordination site (Fe-TPP-phen) and incorporated it to HasA. By adding Ni²⁺ ion to the solution of Fe-TPP-phen HasA monomer, HasA dimer formation was detected. Moreover, we attempted computational structure prediction to investigate this HasA dimer structure and its dynamic behavior.