Polypeptide, photoresist composition including the same, and method of forming pattern using the same

A polypeptide consisting of a region A, a region B, a region C, and a region H, wherein the region A is disposed between the region H and the region B, wherein the region A, the region B, and the region C, are consecutively arranged, wherein

• the region A has an alanine content of 20% or more and consists of a first repeat unit having 4 to 10 consecutive amino acid residues,
• the region B has a tyrosine content of 10% or more and consists of a second repeat unit having 4 to 10 consecutive amino acid residues, and
• the region C has a content of 50-70% or more of at least one of aspartic acid or glutamic acid, and consists of a third repeat unit having 2 to 8 consecutive amino acid residues,
• the polypeptide has a weight average molecular weight of about 3,000 g/mol to about 10,000 g/mol, and
• wherein
• the first repeat unit is represented by Formula 1,
• the second repeat unit is represented by Formula 2,
• the third repeat unit repeat unit is represented by Formula 3, and
• the region H is represented by Formula 4:
• X11-(Ala-X12)n11-X13, Formula 1
• X21-(X22-X23)n21-Tyr, Formula 2
• X31-(X32-X33)n31-X34, Formula 3
• X41-(Ala-X42)n41-X43-Gly-Ala-Ala-Ser, Formula 4
• wherein in Formulae 1, 2, 3, and 4
• X11 and X12 are each independently Gly or Ala, X13 is Ser or Ala, and n11 is an integer of 1 to 4;
• X21 and X23 are each independently Gly or Ala, X22 is Gly, Ala, or Val, and n21 is an integer of 1 to 4;
• X31 to X34 are each independently Asp or Glu, and n31 is an integer of 0 to 3;
• and
• X41 and X42 are each independently Gly or Ala, X43 is Ser or Ala, and n41 is 1 or 2.