Meanwhile, the solubility of protein is determined by various factors. Among them, the hydrophilicity or hydrophobicity of
protein is important. It is based on the ratio of polar and nonpolar amino acids on its surface. However, the lack of information on the 3D structure of SS prevents us from measuring the exact hydrophilicity of SS. Instead, we can roughly assume it is based on the amino acid compositions of each EpSS.