Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata 700 009, India.
J Biosci. 2020;45.
Silkwormsilk protein fibroin is widely exploited to develop novel silk-based biomaterials due to its stable β-sheet structure, providing high crystallinity and tensile strength. The polymorphic behaviour of silk fibroin provides a window to modulate its structural transitions during self-assembly for different functional outcomes. Most studies are therefore mainly focused on formation of well-developed β-sheet structure and self-assembly of silk fibroin which are regulated by many parameters. Glyoxal, a highly reactive α-oxoaldehyde, reacts with different proteins to form advanced glycation end products (AGEs) following Maillard-like reaction. Considering the significance of protein modification by glyoxal-derived AGEs, in the present study the effect of glyoxal (250, 500 and 1000 μM) on the structure of silk fibroin has been investigated. CD and fluorescence studies reveal that higher concentrations of the α-oxoaldehyde induce considerable alterations of secondary and tertiary structure of the protein leading to aggregation following incubation with for 3 weeks. The aggregates exhibit fibrillar morphology with amyloidal nature as evident from SEM, FTIR and XRD experiments. The findings highlight that glycationinduced modification can be a possible approach for modulating the conformation of the silk protein which may be relevant in connection to clinical, biomedical or synthetic biology based applications.
蚕丝蛋白丝素由于其稳定的β-折叠结构，提供了高结晶度和拉伸强度，因此被广泛用于开发新型的基于丝的生物材料。丝素的多晶型行为为调节其自组装过程中的结构转变提供了一个窗口，以实现不同的功能结果。因此，大多数研究主要集中在形成发达的β-折叠结构和丝素的自组装上，这是由许多参数调节的。乙二醛是一种高反应性的α-氧代醛，它与不同的蛋白质反应，形成类似于美拉德反应的晚期糖基化终产物（AGEs）。考虑到乙二醛衍生的 AGEs 对蛋白质修饰的重要性，在本研究中，研究了乙二醛（250、500 和 1000μM）对丝素结构的影响。CD 和荧光研究表明，较高浓度的α-氧代醛会导致蛋白质的二级和三级结构发生相当大的变化，导致在孵育 3 周后发生聚集。这些聚集物表现出纤维状形态，具有淀粉样性质，这从 SEM、FTIR 和 XRD 实验中可以明显看出。研究结果表明，糖基化诱导的修饰可能是调节丝蛋白构象的一种方法，这可能与临床、生物医学或合成生物学相关的应用有关。
