TY - JOUR
T1 - Synthesis of [ 11C]interleukin 8 using a cell-free translation system and l-[ 11C]methionine
AU - Harada, Ryuichi
AU - Furumoto, Shozo
AU - Yoshikawa, Takeo
AU - Ishikawa, Yoichi
AU - Shibuya, Katsuhiko
AU - Okamura, Nobuyuki
AU - Iwata, Ren
AU - Yanai, Kazuhiko
N1 - Funding Information:
The authors appreciate Post Genome Institute Co. Ltd. (Japan) for giving precise technical information on PURESYSTEM. This work was supported by Grants-in-Aid for scientific research (nos. 21390171 and 21650088 ) from the Japan Society of Promotion of Science and the Ministry of Education, Culture, Sports, Science, and Technology in Japan. The authors also thank J. Tsubata, M. Kato and T. Ohnuki for their assistance.
PY - 2012/1
Y1 - 2012/1
N2 - Positron emission tomography (PET), which requires a compound labeled with a positron emitter radioisotope as an imaging probe, is one of the most useful and valuable imaging modalities in molecular imaging. It has several advantages over other imaging modalities, particularly in sensitive and quantitative investigations of molecular functions and processes in vivo. Recent advances in biopharmaceuticals development have increased interest in practical methods for proteins and peptides labeling with positron emitter radioisotope for PET molecular imaging. Here, we propose a novel approach for preparing positron emitter-labeled proteins and peptides based on biochemical synthesis using a reconstituted cell-free translation system. In this study, [ 11C]interleukin 8 (IL-8; MW 9.2 kDa) was successfully synthesized by the cell-free system in combination with l-[ 11C]methionine. The in vitro biochemical reaction proceeded smoothly and gave maximum radioactivity of [ 11C]IL-8 at 20 min with a radiochemical yield of 63%. Purification of [ 11C]IL-8 was achieved by conventional cation exchange and ultrafiltration methods, resulting in enough amount of radioactivity with excellent radiochemical purity (>95%) for small-animal imaging. This study clearly demonstrates that cell-free protein production system combined with positron emitter-labeled amino acid holds great promise as a novel approach to prepare radiolabeled proteins and peptides for PET imaging.
AB - Positron emission tomography (PET), which requires a compound labeled with a positron emitter radioisotope as an imaging probe, is one of the most useful and valuable imaging modalities in molecular imaging. It has several advantages over other imaging modalities, particularly in sensitive and quantitative investigations of molecular functions and processes in vivo. Recent advances in biopharmaceuticals development have increased interest in practical methods for proteins and peptides labeling with positron emitter radioisotope for PET molecular imaging. Here, we propose a novel approach for preparing positron emitter-labeled proteins and peptides based on biochemical synthesis using a reconstituted cell-free translation system. In this study, [ 11C]interleukin 8 (IL-8; MW 9.2 kDa) was successfully synthesized by the cell-free system in combination with l-[ 11C]methionine. The in vitro biochemical reaction proceeded smoothly and gave maximum radioactivity of [ 11C]IL-8 at 20 min with a radiochemical yield of 63%. Purification of [ 11C]IL-8 was achieved by conventional cation exchange and ultrafiltration methods, resulting in enough amount of radioactivity with excellent radiochemical purity (>95%) for small-animal imaging. This study clearly demonstrates that cell-free protein production system combined with positron emitter-labeled amino acid holds great promise as a novel approach to prepare radiolabeled proteins and peptides for PET imaging.
KW - Carbon-11
KW - Cell-free protein synthesis
KW - Imaging
KW - Interleukin 8
KW - Positron
KW - Unnatural amino acid
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U2 - 10.1016/j.nucmedbio.2011.07.005
DO - 10.1016/j.nucmedbio.2011.07.005
M3 - Article
C2 - 21958850
AN - SCOPUS:84855311827
VL - 39
SP - 155
EP - 160
JO - International journal of radiation applications and instrumentation. Part B, Nuclear medicine and biology
JF - International journal of radiation applications and instrumentation. Part B, Nuclear medicine and biology
SN - 0969-8051
IS - 1
ER -