School of Chemical Engineering and Analytical Sciences and Manchester Interdisciplinary Biocentre, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
Langmuir. 2010 Jul 6;26(13):11297-303. doi: 10.1021/la100623y.
We investigate the possibility of using the protease thermolysin to drive the synthesis and gelation of ionic-complementary peptides from nongelling precursors. In this system, short peptide fragments are continuously interconverted to form a dynamic peptide library, which eventually favors synthesis of peptides that are thermodynamically stabilized by molecular self-assembly. Thermolysin was added at a fixed concentration (0.3 mg mL(-1)) to solutions (0-300 mg mL(-1)) of the short tetrapeptide FEFK. Initially, the protease partially hydrolyzed the tetrapeptide into dipeptides in all samples. Subsequently, longer peptide sequences were found to form through reverse-hydrolysis. The stability of the different sequences was found to be dependent on their self-assembling properties. The sequences that self-assembled into antiparallel beta-sheet rich fibers became the stable products for the reverse hydrolysis reaction, while the others formed were unstable and disappeared with increasing incubation time. Ultimately, the main product of the system was octapeptide, which suggests that it represents the thermodynamically favored product of this dynamic library. Its concentration dictated the gelation behavior of the sample, and gels with moduli up to 25 kPa where obtained depending on the initial concentration of tetrapeptide.
我们研究了使用蛋白酶糜蛋白酶来驱动离子互补肽从非胶凝前体的合成和凝胶化的可能性。在这个系统中，短肽片段不断相互转化，形成一个动态的肽库，最终有利于热力学上通过分子自组装稳定的肽的合成。在浓度固定（0.3 mg mL(-1)）的情况下，将蛋白酶添加到短四肽 FEFK 的溶液（0-300 mg mL(-1)）中。最初，蛋白酶在所有样品中部分水解四肽成二肽。随后，发现较长的肽序列通过反向水解形成。不同序列的稳定性被发现取决于它们的自组装特性。那些自组装成富含反平行β-折叠的纤维的序列成为反向水解反应的稳定产物，而其他形成的序列不稳定，随着孵育时间的增加而消失。最终，该系统的主要产物是八肽，这表明它代表了这个动态库的热力学优势产物。其浓度决定了样品的凝胶行为，并且取决于四肽的初始浓度，可以得到模量高达 25 kPa 的凝胶。
