Silk fibroin (SF)

Silk fibroin is the main structural protein component of silk fibers produced by silkworms and certain other insects. It consists primarily of heavy and light polypeptide chains (the heavy chain ~390 kDa and the light chain ~26 kDa, joined by a disulfide bond) and is associated with a glycoprotein (P25, ~25-30 kDa) in a 6:6:1 molar ratio. The protein’s sequence is highly repetitive and rich in glycine, alanine, and serine, which contribute to its highly organized anti-parallel β-sheet secondary structure. This structure imparts silk fibroin with remarkable mechanical properties, including strength, elasticity, and biocompatibility. Silk fibroin is widely studied and used as a biomaterial for medical and engineering applications—such as tissue scaffolds, wound dressing, and drug delivery matrices—because of its mechanical performance and biocompatibility. It is not, however, an endogenous signaling protein or molecular target in human pharmacology, nor is it involved in canonical disease signaling pathways.

Other names

FibroinSilk proteinBombyx mori silk fibroin