Exploring the functional variations in fibroin and sericin: Insights into amino acid composition and biomedical applications

Abstract

The amino acid composition of fibroin and sericin, two primary silk proteins, plays a pivotal role in determining their functional and structural properties. Cocoon fibroin and posterior silk gland fibroin exhibit similar amino acid profiles, with glycine (43.70% and 42.90%, respectively) and alanine (28.80% and 30.00%, respectively) being the most abundant, providing flexibility and structural stability. In contrast, sericin has a distinct composition, with glycine content significantly lower (10.00%), while serine is notably higher (33.40%). This study reveals that while both fibroins share similar amino acid distributions, sericin’s high serine concentration enhances its adhesive properties. Other amino acids, such as tyrosine, valine, aspartic acid, and glutamic acid, were also found to vary across the proteins, indicating their role in the unique functionalities of each. The results underline the specialized roles these proteins play, with fibroin contributing primarily to structural integrity and sericin to adhesion. Understanding these variations provides valuable insights for the development of silk-based biomaterials with tailored properties for various industrial and biomedical applications.