What is the chemical formula for fabric silk?

Silk is primarily composed of proteins, specifically fibroin, which does not have a fixed chemical formula like small molecules. However, the repeating units of fibroin can be represented by the general formula (C15H18N2O6S)n, where "n" denotes the number of repeating units in the polymer chain. Silk's structure also includes sericin, another protein that contributes to its properties. Overall, silk is a complex natural polymer rather than a single chemical compound.