CBMA (Centre of Molecular and Environmental Biology), Department of Biology, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
AMB Express. 2013 Feb 5;3(1):11. doi: 10.1186/2191-0855-3-11.
Silk-elastin-like polymers (SELPs) are protein-based polymers composed of repetitive amino acid sequence motifs found in silk fibroin (GAGAGS) and mammalian elastin (VPGVG). These polymers are of much interest, both from a fundamental and applied point of view, finding potential application in biomedicine, nanotechnology and as materials. The successful employment of such polymers in such diverse fields, however, requires the ready availability of a variety of different forms with novel enhanced properties and which can be simply prepared in large quantities on an industrial scale. In an attempt to create new polymer designs with improved properties and applicability, we have developed four novel SELPs wherein the elastomer forming sequence poly(VPGVG) is replaced with a plastic-like forming sequence, poly(VPAVG), and combined in varying proportions with the silk motif. Furthermore, we optimised a simplified production procedure for these, making use of an autoinduction medium to reduce process intervention and with the production level obtained being 6-fold higher than previously reported for other SELPs, with volumetric productivities above 150 mg/L. Finally, we took advantage of the known enhanced stability of these polymers in developing an abridged, non-chromatographic downstream processing and purification protocol. A simple acid treatment allowed for cell disruption and the obtention of relative pure SELP in one-step, with ammonium sulphate precipitation being subsequently used to enable improved purity. These simplified production and purification procedures improve process efficiency and reduce costs in the preparation of these novel polymers and enhances their potential for application.
丝弹性蛋白类似聚合物（SELPs）是由丝纤维蛋白（GAGAGS）和哺乳动物弹性蛋白（VPGVG）中发现的重复氨基酸序列基元组成的基于蛋白质的聚合物。这些聚合物从基础和应用的角度来看都非常有趣，在生物医学、纳米技术和材料方面都有潜在的应用。然而，为了在如此多样化的领域成功应用这些聚合物，需要随时提供各种具有新颖增强性能的不同形式，并且可以在工业规模上大量简单地制备。为了创造具有改进性能和适用性的新型聚合物设计，我们开发了四种新型 SELPs，其中弹性体形成序列聚（VPGVG）被类似塑料的形成序列聚（VPAVG）取代，并与丝基元以不同比例结合。此外，我们优化了这些聚合物的简化生产工艺，利用自动诱导培养基减少工艺干预，获得的产量是以前报道的其他 SELPs 的 6 倍，体积生产率超过 150mg/L。最后，我们利用这些聚合物已知的增强稳定性来开发一种简化的、非色谱的下游处理和纯化方案。简单的酸处理可用于细胞破碎，并在一步中获得相对纯的 SELP，随后使用硫酸铵沉淀以提高纯度。这些简化的生产和纯化程序提高了这些新型聚合物的制备过程效率并降低了成本，增强了它们的应用潜力。
