College of Food Science and Technology and MOE Key Laboratory of Environment Correlative Dietology, Huazhong Agricultural University, Wuhan 430070, PR China; Collaborative Innovation Center for Efficient and Health Production of Fisheries in Hunan Province, Hunan, Changde 415000, PR China.
Key Laboratory of Sensing Technology and Biomedical Instrument of Guangdong Province, School of Biomedical Engineering, Sun Yat-sen University, Guangzhou 510006, PR China.
Mater Sci Eng C Mater Biol Appl. 2019 Mar;96:446-457. doi: 10.1016/j.msec.2018.11.043. Epub 2018 Nov 27.
This work aimed to improve yield of collagen from the grass carp skin by employing different strategies (acid-acid method, pepsin-pepsin method and acid-pepsin method, denoted as A-A, P-P, A-P, respectively). And further to conduct quantitative characterization on structural properties, self-assembly kinetics and gelation properties of these collagens. Herein, a two-step collagen extraction method (pepsin-pepsin) was established with the high yield. Meanwhile, structural measurements of high-yield collagen (pepsin-soluble collagen, PSC) and acid-soluble collagen (ASC) indicated that both collagens maintained the typical triple helical conformation of collagen type I. Moreover, the fibrillogenesis tests of PSC and ASC at the various temperatures confirmed that self-assembly were the entropy-driven process. The gelation time of both ASC and PSC was determined by the dynamic time sweep at the different frequencies combined with Winter's criterion. The self-assembly kinetics results showed that fibrillogenesis rate for ASC solution was faster, and more liable to gelation relative to PSC. Mechanical measurements suggested that ASC showed the more resistance ability to deformation than PSC due to more complicated architecture, confirmed by higher fractal dimension. However, the equivalent typical assemblies of PSC to ASC at the various stages can still be expected via controlling incubation time or temperature under the guidance of Arrhenius equation. This study would provide some strategies for achieving maximum utilization of waste biomass and significant insights into the mechanisms underlying the quantitative differences in multiple hierarchy conformation (molecule, fibrillogenesis and hydrogel) of ASC and PSC, which may benefit for subsequent design, development and optimization of collagen-based hydrogels in biomedical industries.
本工作旨在通过采用不同策略（酸-酸法、胃蛋白酶-胃蛋白酶法和酸-胃蛋白酶法，分别表示为 A-A、P-P 和 A-P）来提高草鱼皮胶原蛋白的得率。并进一步对这些胶原蛋白的结构特性、自组装动力学和胶凝性质进行定量表征。在此，建立了一种两步胶原蛋白提取方法（胃蛋白酶-胃蛋白酶），具有较高的产率。同时，高产量胶原蛋白（胃蛋白酶可溶胶原蛋白，PSC）和酸可溶胶原蛋白（ASC）的结构测量表明，两种胶原蛋白均保持了 I 型胶原蛋白的典型三螺旋构象。此外，在不同温度下 PSC 和 ASC 的原纤维形成测试证实，自组装是熵驱动的过程。ASC 和 PSC 的凝胶时间通过不同频率下的动态时间扫描结合 Winter 准则确定。自组装动力学结果表明，ASC 溶液的原纤维形成速率更快，相对于 PSC 更容易凝胶化。力学测量表明，由于 ASC 具有更复杂的结构，其抵抗变形的能力比 PSC 更强，这一点可以通过更高的分形维数来证实。然而，通过 Arrhenius 方程的指导，控制孵育时间或温度，仍可以期望 PSC 达到与 ASC 各个阶段相当的典型组装体。本研究为实现最大利用废物生物质提供了一些策略，并深入了解 ASC 和 PSC 在多层次构象（分子、原纤维形成和水凝胶）方面的定量差异的机制，这可能有利于随后在生物医学工业中对基于胶原蛋白的水凝胶进行设计、开发和优化。
