Page 118 - ebook

[A. Biochemistry/Molecular Biology] A-59

Metal-Mediated Protein Assembly Using a Genetically

Incorporated Metal-Chelating Amino Acid

Hyun Soo Lee¹*

¹Chemistry, Sogang University, Seoul 04107, Korea

Many proteins function in oligomeric forms for their sophisticated functions. The construction of protein assemblies
has great potential for biosensors, enzyme catalysis, and biomedical applications. In designing protein assemblies,

a critical process is to create protein–protein interaction (PPI) networks at defined sites of a target protein. In this
report, a metal-chelating amino acid, 2,2′-bipyridylalanine (BPA), was genetically introduced into defined sites of a

monomeric protein and used to form protein oligomers. Depending on the number of BPAs introduced into the
protein and the species of metal ions (Ni2+ and Cu2+), dimers or oligomers with different oligomerization patterns

were formed by complexation with a metal ion. Oligomer sizes could also be controlled by incorporating two BPAs
at different locations with varied angles to the center of the protein. When three BPAs were introduced, the

monomeric protein formed a large complex with Ni2+. In addition, when Cu2+ was used for complex formation
with the protein containing two BPAs, a linear complex was formed. The method proposed in this report is technically

simple and generally applicable to various proteins with interesting functions. Therefore, this method would be
useful for the design and construction of functional protein assemblies.