Study of Nanofibrils Formation of Fibroin Protein in Specific Thermal and Acidity Conditions

Amyloid fibrils are insoluble arranged aggregates of proteins that are fibrillar in structure and related to many diseases (at least 20 types of illnesses) and also create many pathologic conditions. Therefore understanding the circumstance of fibril formation is very important. This study aims to work on fibrillar structure formation of fibroin (as a model protein). In this experimental study, fibroin was extracted from bombyx mori silk cocoon, and the concentration was obtained by Bradford method. The protein was incubated in a wide range of times (0 min to 7 days) in specific acidity and thermal conditions (pH=1.6, T=70 °C). The assays of UV-vis spectroscopy with congo red, field emission scanning electron microscopy, transmission electron microscopy, atomic force microscopy and circular dichroism spectroscopy were employed to monitor the fibrillation process. Fibroin assemblies were formed upon the process of aggregation and fibril formation with a variety of morphology ranging from nanoparticles to elongated fibrils. The results showed progressive pathway of fibril formation.