Design of a binuclear Ni(II)-iminodiacetic acid (IDA) complex for selective recognition and covalent labeling of His-tag fused proteins.
Selective protein labeling with a small molecular probe is a versatile method for elucidating protein functions under live-cell conditions. In this Letter, we report the design of the binuclear Ni(II)-iminodiacetic acid (IDA) complex for selective recognition and covalent labeling of His-tag-fused proteins. We found that the Ni(II)-IDA complex 1-2Ni(II) binds to the His6-tag (HHHHHH) with a strong binding affinity (Kd=24 nM), the value of which is 16-fold higher than the conventional Ni(II)-NTA complex (Kd=390 nM). The strong binding affinity of the Ni(II)-IDA complex was successfully used in the covalent labeling and fluorescence bioimaging of a His-tag fused GPCR (G-protein coupled receptor) located on the surface of living cells.
Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Ikuko
I
Takahira
Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Hirokazu
H
Fuchida
Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Shigekazu
S
Tabata
Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Naoya
N
Shindo
Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
Shohei
S
Uchinomiya
Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
Itaru
I
Hamachi
Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: ojida@phar.kyushu-u.ac.jp.
Akio
A
Ojida
D015195:Drug Design; D057809:HEK293 Cells; D006639:Histidine / Q000737:chemistry*; D006801:Humans; D007098:Imino Acids / Q000737:chemistry*; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000737:chemistry*; D013194:Staining and Labeling; D013329:Structure-Activity Relationship
D007098:Imino Acids; D009942:Organometallic Compounds; D011993:Recombinant Fusion Proteins; D006639:Histidine; D009532:Nickel; C008109:iminodiacetic acid
Bioimaging; His tag; Molecular recognition; Ni complex; Protein labeling