Development of a Synthetic Biosensor for Chemical Exchange MRI Utilizing In Silico Optimized Peptides.
Development of a Synthetic Biosensor for Chemical Exchange MRI Utilizing In Silico Optimized Peptides.
复制标题
利用计算机优化的肽开发用于化学交换 MRI 的合成生物传感器。
DOI：
10.1101/2023.03.08.531737
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Gilad,AssafA
中科院分区：
文献类型：
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作者：
Fillion,AdamJ;Bricco,AlexanderR;Lee,HarveyD;Korenchan,David;Farrar,ChristianT;Gilad,AssafA
化学交换饱和转移（CEST）MRI已被确定为一种新的替代经典的诊断成像。在过去的几十年里，已经进行了许多研究来确定可能的CEST试剂，例如内源性表达的化合物或蛋白质，这些试剂可用于与微创手术形成对比，并降低或消除毒性水平。近年来，人们对基因工程CEST造影剂的产生越来越感兴趣，通常基于具有CEST造影剂的现有蛋白质或经修饰以产生CEST造影剂。我们已经开发了一种用于肽序列进化的计算机模拟方法，以优化CEST对比度，并表明这些肽可以组合起来创建用于CEST MRI的从头生物传感器。一个单一的蛋白质，superCESTide，被设计为198个氨基酸。SuperCESTide在E.大肠杆菌中，并通过尺寸排阻色谱法纯化。由superCESTide产生的磁转移率不对称性与在先前CEST报告子中观察到的水平相当，例如硫酸鱼精蛋白（鲑鱼鱼精蛋白）和人鱼精蛋白。这些数据表明，具有针对CEST对比度计算机优化的序列的新型肽，其利用更全面的氨基酸范围，当组装成在复杂的生活环境中表达的蛋白质单元时，仍然可以产生对比度。
Chemical exchange saturation transfer (CEST) MRI has been identified as a novel alternative to classical diagnostic imaging. Over the last several decades, many studies have been conducted to determine possible CEST agents, such as endogenously expressed compounds or proteins, that can be utilized to produce contrast with minimally invasive procedures and reduced or non‐existent levels of toxicity. In recent years there has been an increased interest in the generation of genetically engineered CEST contrast agents, typically based on existing proteins with CEST contrast or modified to produce CEST contrast. We have developed an in silico method for the evolution of peptide sequences to optimize CEST contrast and showed that these peptides could be combined to create de novo biosensors for CEST MRI. A single protein, superCESTide, was designed to be 198 amino acids. SuperCESTide was expressed inE. coliand purified with size exclusion chromatography. The magnetic transfer ratio asymmetry generated by superCESTide was comparable to levels seen in previous CEST reporters, such as protamine sulfate (salmon protamine) and human protamine. These data show that novel peptides with sequences optimized in silico for CEST contrast that utilize a more comprehensive range of amino acids can still produce contrast when assembled into protein units expressed in complex living environments.