IMPROVED N-TERMINAL CAPING MODULES FOR DESIGNED PROTEINS WITH ANKIRIN REPEAT

摘要

1. A binding protein comprising at least one ankyrin repeat domain, wherein said ankyrin repeat domain includes an N-terminal capping module having the amino acid sequence GSDLGKKLLE AARAGQDDEV RILLKAGADV NA (SEQ ID NO: 14) or GSDLGKKLLE AARAGQDDDEV RELL 15), in which the amino acid residue L at position 24 of SEQ ID NO: 14 or SEQ ID NO: 15 is optionally substituted with V, I or A; up to 9 amino acids of SEQ ID NO: 14 or SEQ ID NO: 15 at other positions, other than position 24 are not necessarily replaced by any amino acids; in which G in position 1 and / or S in position 2 of SEQ ID NO: 14 or SEQ ID NO: 15 are optionally absent. 2. The binding protein according to claim 1, wherein said N-terminal capping module provides a higher Tm in PBS for said ankyrin repeat domain compared to an ankyrin repeat domer that has the same amino acid sequence of the N-terminal capping module except that the amino acid residue corresponding to position 24 of SEQ ID NO: 14 or SEQ ID NO: 15 is M instead of L, V, I or A.3. The binding protein according to claim 1, wherein the amino acid residue A at position 26 of SEQ ID NO: 14 or SEQ ID NO: 15 is not substituted or is replaced by H, Y, K or R.4. The binding protein according to claim 1, wherein the amino acid residue R at position 21 of SEQ ID NO: 14 or SEQ ID NO: 15 is not substituted or is replaced by E.5. The binding protein according to claim 1, wherein amino acid residue I at position 22 of SEQ ID NO: 14 or amino acid residue E at position 22 of SEQ ID NO: 15 is not substituted or is replaced by V.6. The binding protein according to claim 1, wherein the amino acid residue K is at position 25 of SEQ ID NO: 14 or SEQ ID NO: 15