The specific labelling of proteins in recent years has made use of self-labelling proteins, such as the SNAP-tag^® and the Halotag^®. These enzymes, by their nature or suitably engineered, have the ability to specifically react with their respective substrates, but covalently retaining a part of them in the catalytic site upon reaction. This led to the synthesis of substrates conjugated with, e.g., fluorophores (proposing them as alternatives to fluorescent proteins), but also with others chemical groups, for numerous biotechnological applications. Recently, a mutant of the OGT from Saccharolobus solfataricus (H⁵) very stable to high temperatures and in the presence of physical and chemical denaturing agents has been proposed as a thermostable SNAP-tag^® for in vivo and in vitro harsh reaction conditions. Here, we show two new thermostable OGTs from Thermotoga neapolitana and Pyrococcus furiosus, which, respectively, display a higher catalytic activity and thermostability respect to H⁵, proposing them as alternatives for in vivo studies in these extreme model organisms.

中文翻译：

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下地狱之旅：用于高温生物技术的新型耐热蛋白质标签。

近年来蛋白质的特异性标记利用了自标记蛋白，如SNAP-tag ^®和Halotag ^®。这些酶，根据它们的性质或经过适当设计，具有与它们各自的底物特异性反应的能力，但在反应时将它们的一部分共价保留在催化位点。这导致了与例如荧光团（提出它们作为荧光蛋白的替代品）以及与其他化学基团缀合的底物的合成，用于许多生物技术应用。最近，来自Saccharolobus solfataricus (H ⁵) 对高温和在存在物理和化学变性剂的情况下非常稳定，已被提议作为热稳定的 SNAP-tag ^®用于体内和体外苛刻的反应条件。在这里，我们展示了来自Thermotoga neapolitana和Pyrococcus furiosus的两种新的热稳定 OGT ，它们分别显示出对 H ⁵更高的催化活性和热稳定性，建议将它们作为这些极端模型生物体内研究的替代品。