Selective Labeling of Proteins on Living Cell Membranes Using Fluorescent Nanodiamond Probes.
The impeccable photostability of fluorescent nanodiamonds (FNDs) is an ideal property for use in fluorescence imaging of proteins in living cells. However, such an application requires highly specific labeling of the target proteins with FNDs. Furthermore, the surface of unmodified FNDs tends to adsorb biomolecules nonspecifically, which hinders the reliable targeting of proteins with FNDs. Here, we combined hyperbranched polyglycerol modification of FNDs with the β-lactamase-tag system to develop a strategy for selective imaging of the protein of interest in cells. The combination of these techniques enabled site-specific labeling of Interleukin-18 receptor alpha chain, a membrane receptor, with FNDs, which eventually enabled tracking of the diffusion trajectory of FND-labeled proteins on the membrane surface.
Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan. sotoma.shingo.5x@kyoto-u.ac.jp.
Shingo
S
Sotoma
Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan. jniimr@gmail.com.
Jun
J
Iimura
Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan. igarashi.ryuji.78r@st.kyoto-u.ac.jp.|PRESTO, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan. igarashi.ryuji.78r@st.kyoto-u.ac.jp.
Ryuji
R
Igarashi
Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Kyoto 615-8501, Japan. hirosawa@frontier.kyoto-u.ac.jp.
Koichiro M
KM
Hirosawa
Department of Pediatrics, Graduate School of Medicine, Gifu University, Yanagido 1-1, Gifu 501-1194, Japan. ohnishih@gifu-u.ac.jp.
Hidenori
H
Ohnishi
Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871, Japan. smizukami@mls.eng.osaka-u.ac.jp.|Immunology Frontier Research Center, Osaka University, Yamadaoka 3-1, Suita, Osaka 565-0871, Japan. smizukami@mls.eng.osaka-u.ac.jp.
Shin
S
Mizukami
Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871, Japan. kkikuchi@mls.eng.osaka-u.ac.jp.|Immunology Frontier Research Center, Osaka University, Yamadaoka 3-1, Suita, Osaka 565-0871, Japan. kkikuchi@mls.eng.osaka-u.ac.jp.
Kazuya
K
Kikuchi
Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Kyoto 615-8501, Japan. tfujiwara@icems.kyoto-u.ac.jp.
Takahiro K
TK
Fujiwara
Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan. shirakawa@moleng.kyoto-u.ac.jp.
Masahiro
M
Shirakawa
Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake, Sakyo-ku, Kyoto 606-8502, Japan. tochio@mb.biophys.kyoto-u.ac.jp.
Hidehito
H
Tochio
membrane protein; nanodiamond; nitrogen-vacancy center; polyglycerol; β-lactamase tag