Department of Applied Sciences and Mechatronics, Munich University of Applied Sciences, Lothstrasse 34, 80334, Munich, Germany.
Center for Nanoscience (CeNS), Schellingstrasse 4, 80799, Munich, Germany.
Angew Chem Int Ed Engl. 2019 Jul 15;58(29):9787-9790. doi: 10.1002/anie.201902752. Epub 2019 Jun 24.
Amide bonds, which include peptide bonds connecting amino acids in proteins and polypeptides, give proteins and synthetic polyamides their enormous strength. Although proteins and polyamides sustain mechanical force in nature and technology, how forces affect amide and peptide bond stability is still unknown. Using single-molecule force spectroscopy, we discover that forces of only a few hundred pN accelerate amide hydrolysis 10 -fold, an acceleration hitherto only known from proteolytic enzymes. The drastic acceleration at low force precedes a moderate additional acceleration at nN forces. Quantum mechanochemical ab initio calculations explain these experimental results mechanistically and kinetically. Our findings reveal that, in contrast to previous belief, amide stability is strongly force dependent. These calculations provide a fundamental understanding of the role of mechanical activation in amide hydrolysis and point the way to potential applications from the recycling of macromolecular waste to the design of bioengineered proteolytic enzymes.
酰胺键,包括连接蛋白质和多肽中氨基酸的肽键,赋予蛋白质和合成聚酰胺巨大的强度。尽管蛋白质和聚酰胺在自然界和技术中承受机械力,但力如何影响酰胺键和肽键的稳定性仍不清楚。使用单分子力谱学,我们发现只有几百皮牛顿的力就能使酰胺水解加速 10 倍,这种加速作用以前只在蛋白酶中才知道。在低力下的剧烈加速之前是 nN 力下的适度额外加速。量子机械化学从头计算从机械和动力学上解释了这些实验结果。我们的发现表明,与之前的观点相反,酰胺键的稳定性强烈依赖于力。这些计算为机械激活在酰胺水解中的作用提供了基本的理解,并为从大分子废物的回收利用到生物工程蛋白酶设计的潜在应用指明了方向。