合成疗法与抗生素耐药性的抵抗

There are currently only a few synthetic agents that bind to and block the widespread membrane transport proteins, ATP-binding cassette transporters (ABC). Scientists at Goethe University and the University of Tokyo identified four of these macrocyclic peptides as models for a novel generation of active substances. They used methods for which the scientists involved are considered world leaders.

目前只有少数几种合成剂可以结合并阻断广泛的膜转运蛋白，即ATP结合盒转运蛋白(ABC)。歌德大学和东京大学的科学家们将其中的四种大环肽鉴定为新一代活性物质的模型。他们使用了被认为是世界领导者的科学家所采用的方法。

Thanks to deep sequencing, an extremely fast and efficient read-out procedure, the desired macrocyclic peptides could be filtered out of a "library" of macrocyclic peptides comprising trillions of variants (1 with 12 zeroes)—a number that exceeds the number of stars in the Milky Way. The fact that such an enormous amount exists at all is related to a novel procedure: By reprogramming the genetic code, amino acids can be used specifically as active components that are not otherwise used in the cell. In particular, their circular, closed structure distinguishes them from natural proteins.

通过深度测序，极其快速和高效的读出程序，可以从包含数万亿个变体(1个带有12个零)的大环肽的“库”中过滤出所需的大环肽——这个数字超过了银河系中的恒星数量。如此大量的氨基酸存在的事实与一个新颖的过程有关: 通过重新编码遗传密码，氨基酸可以被特别用作细胞中不会被其他方式使用的活性成分。特别是，它们的圆形封闭结构使它们区别于天然蛋白质。

Credit: Robert Tampé, Institute for Biochemistry, Biocentre, Goethe University Frankfurt

"Because these therapeutics are cyclic, they break down less rapidly in the cell," explains Robert Tampé, Director of the Institute of Biochemistry at Goethe University. "In addition, the ring-shaped active substances are restricted in their spatial structure, so they bind to the target molecule without major rearrangements." A third distinguishing feature makes macrocyclic peptides particularly attractive for scientists: When the active substances are produced, their building instructions are supplied as a "barcode." If certain therapeutics are selected from among a trillion synthetically produced ones, they carry their "name tags" with them, so to speak.

歌德大学生物化学研究所所长罗伯特·坦佩解释说: “因为这些疗法是周期性的，所以它们在细胞中分解的速度较慢。”“此外，环状活性物质的空间结构受到限制，因此它们与目标分子结合而不发生重大的重排。”第三个区别特征使得大环肽对科学家特别有吸引力: 当活性物质产生时，它们的构建指令以“条形码”的形式提供如果某种疗法是从一万亿个人工合成的药物中选出来的，那么可以这么说，它们随身带着它们的“名称标签”。

So what role do synthetic therapeutics play in antibiotic resistance in bacteria or multidrug resistance in tumor cells? What happens when they encounter the ATP-driven transport molecule that is responsible for resistance by carrying the chemotherapeutic agents out of the cell? In a nutshell, the drugs block the transporter by binding to it. This can happen at the beginning or at the end of a transport process, when the transporter is in a resting state. However, since the scientists can slow down the transport process so that it is carried out in slow motion, they can identify the agents that "enter" in the middle of the transport process and "hold" the membrane protein in its respective position. In this way, the researchers gain an insight into the choreography of the transport process as if through the images of a film strip.

那么，合成疗法在细菌的抗生素抗药性或肿瘤细胞的多药耐药性中扮演什么角色呢?当他们遇到 ATP 驱动的转运分子时会发生什么? 这种转运分子通过携带化疗药物离开细胞而产生耐药性?简而言之，药物通过与转运蛋白结合来阻断转运蛋白。这可能发生在运输过程的开始或结束时，当运输者处于休眠状态。然而，由于科学家们可以减缓运输过程，使其以慢动作进行，他们可以识别在运输过程中“进入”的介质，并“保持”膜蛋白在其各自的位置。通过这种方式，研究人员就像通过电影胶片的图像一样深入了解了传输过程的编排。

These insights have already led to a "paradigm shift" in science, as Tampé explains: "Until now, we have assumed that ATP hydrolysis (an energy-releasing splitting process) provides the energy for transport through the membrane. However, this is only indirectly the case. It is the event of the binding of the ATP molecule that pushes substances out of the cell. The energy of hydrolysis, on the other hand, is used to return the ABC transporter to its initial state." The research groups at Goethe University and the University of Tokyo are convinced that these and other insights into membrane processes will point to the development of future medicines.

这些观点已经导致了科学上的“范式转变”，正如坦佩解释的那样: “直到现在，我们一直假定 ATP 水解(一种能量释放分裂过程)提供了通过膜传输的能量。但是，这仅仅是间接的情况是，ATP分子的结合将物质从细胞中推出。另一方面，水解的能量被用来使 ABC 运输机恢复到初始状态。”歌德大学和东京大学的研究小组确信，这些和其他关于膜过程的观点将指向未来药物的发展。

Basic research on cellular membranes and membrane proteins already has a long tradition in Frankfurt. Robert Tampé elucidated essential mechanisms of ATP-driven transport proteins and cellular machinery of adaptive immune response and quality control, which together with this new publication can provide approaches for applied drug research. Tampé was head of the Collaborative Research Centre "Transport and Communication across Biological Membranes" (SFB 807), which expired at the end of 2020. Meanwhile the concept for a new research center on highly dynamic processes related to protein networks and machineries in cellular membranes is already under development. In the long term, the research results should reveal new possibilities for the therapy of molecular diseases, infections and cancer.

细胞膜和膜蛋白的基础研究在法兰克福已经有很长的历史了。罗伯特·坦佩阐明了 ATP 驱动的转运蛋白和细胞机制的适应性免疫反应和质量控制的基本机制，这一新的出版物可以提供应用药物研究的方法。坦佩是合作研究中心”跨越生物膜的运输和通信”(SFB 807)的负责人，该中心于2020年底到期。与此同时，一个关于蛋白质网络和细胞膜机制高度动态过程的新研究中心的概念已经在发展之中。从长远来看，研究结果将为分子疾病、感染和癌症的治疗提供新的可能性。