Metal-substituted protein MRI contrast agents engineered for enhanced relaxivity and ligand sensitivity.
Metal-substituted protein MRI contrast agents engineered for enhanced relaxivity and ligand sensitivity.
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DOI：
10.1021/ja107936d
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发表时间：
2011-02-02
影响因子：
15
通讯作者：
Jasanoff A
中科院分区：
文献类型：
--
作者：
Lelyveld VS;Brustad E;Arnold FH;Jasanoff A
工程金属蛋白是一种灵活的新型分析物敏感分子显像剂，可通过磁共振成像（MRI）检测到，但其造影剂的造影剂效果通常弱于人工合成的。为了增强来自细胞色素P450 BM3 （BM3h）血红素结构域的物质的质子弛豫性，我们形成了含有锰（III）的蛋白质，其电子自旋比天然铁元素高。通过在大肠杆菌中与细菌血红素转运蛋白ChuA共表达BM3h变异体，并在生长培养基中添加Mn3+-原卟啉IX，实现了金属取代。在4.7 t时，与天然BM3h相比，锰BM3h突变体的T1弛缓度高出2.6倍。将chua介导的卟啉取代到一系列耐热嵌合P450结构域上，得到了稳定的高弛缓度BM3h衍生物，在与花生四烯酸（P450酶的天然配体和生物信号通路的重要组成部分）结合时，其弛缓度变化达到63%。这项工作表明，通过在蛋白质工程师可用的方法工具包中包括金属替代，可以轻松地创建具有强大配体敏感性的基于蛋白质的MRI传感器。
Engineered metalloproteins constitute a flexible new class of analyte-sensitive molecular imaging agents detectable by magnetic resonance imaging (MRI), but their contrast effects are generally weaker than synthetic agents. To augment the proton relaxivity of agents derived from the heme domain of cytochrome P450 BM3 (BM3h), we formed manganese(III)-containing proteins that have higher electron spin than their native ferric iron counterparts. Metal substitution was achieved by coexpressing BM3h variants with the bacterial heme transporter ChuA in Escherichia coli and supplementing the growth medium with Mn3+-protoporphyrin IX. Manganic BM3h variants exhibited up to 2.6-fold higher T1 relaxivities relative to native BM3h at 4.7 T. Application of ChuA-mediated porphyrin substitution to a collection of thermostable chimeric P450 domains resulted in a stable, high-relaxivity BM3h derivative displaying a 63% relaxivity change upon binding of arachidonic acid, a natural ligand for the P450 enzyme and an important component of biological signaling pathways. This work demonstrates that protein-based MRI sensors with robust ligand sensitivity may be created with ease by including metal substitution among the toolkit of methods available to the protein engineer.
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影响因子：
3.3
作者：
Lelyveld, Victor S.;Atanasijevic, Tatjana;Jasanoff, Alan
通讯作者：
Jasanoff, Alan
DOI：
10.1073/pnas.79.19.5758
发表时间：
1982-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
GELB, MH;TOSCANO, WA;SLIGAR, SG
通讯作者：
SLIGAR, SG
影响因子：
3.3
作者：
Sun, PZ;Schoening, ZB;Jasanoff, A
通讯作者：
Jasanoff, A
影响因子：
1.6
作者：
Varnado, CL;Goodwin, DC
通讯作者：
Goodwin, DC
影响因子：
3.3
作者：
Vymazal, J;Zak, O;Brooks, RA
通讯作者：
Brooks, RA