In Silico Investigations of Silk Fibroin Peptides Highlight their Therapeutic Values towards Wound Healing

This work validates an in vitro observation that silk peptides derived from the α-chymotrypsin digestion of fibroin heavy chain promote wound healing properties. A molecular level evidence of binding of these peptide fragments to growth factors, their receptors and the corresponding ligand-receptor complexes has been provided. The strengths of interactions and possible conformational changes caused by binding of the select three fibroin peptide fragments to various (fifteen) target combinations have been evaluated. The analysis indicates that a number of target residues have been found to be involved in forming convincing hydrogen bonds and hydrophobic interactions with the three fibroin peptides, thus facilitating the wound healing process. Though very few of them were also involved in interactions with the amino acids at the ligand-ligand, receptor-receptor and ligand-receptor interfaces, it is proposed that the binding does not hinder the ligand-receptor interactions. In the first two peptides, the polar amino acids play a significant role in interacting with the targets. However, in case of the third peptide, due to its higher non-polar composition, the overall interactions are stabilized by hydrophobic interactions. This molecular level appreciation strengthens the fact that silk fibroin peptides could be exploited towards creating medicaments for wound healing and cosmetic surgeries.