Figure 5:

Different sources of SF proteins.In nature the protein can be made available from silkworm moths, honey bees, spiders, wasp and laccwings. The fibroin obtained from silk mainly consits of light chains and heavy chains linked by disulphide bonds. The heavy chain is comprised of crystalline and amorphous regions. The crystalline regions consist of glycine-alanine repeats interconnected with serine and tyrosine amino acids while the amorphous regions consist of amino acids such as aspartic acid.