Cyclic peptide, cell scaffold material, cell separating material, and medium

1 . A cyclic peptide comprising:

a cyclic segment comprising an RGD sequence and having 8 to 14 amino acid residues,

a thioether bond being formed between an amino acid residue X a located on a most N-terminal side of the cyclic segment and an amino acid residue X b located on a most C-terminal side of the cyclic segment,

wherein one of the amino acid residue X a and the amino acid residue X b is a 2-amino-4-acetylamino-butanoic acid residue, an N-δ-acetyl-ornithine residue, or an N-ε-acetyl-lysine residue, and

the other one of the amino acid residue X a and the amino acid residue X b is an L-homocysteine residue or a D-homocysteine residue,

wherein the α carbon of the 2-amino-4-acetylamino-butanoic acid residue, the N-δ-acetyl-ornithine residue, or the N-ε-acetyl-lysine residue is separated from the sulfur atom of the L-homocysteine residue or the D-homocysteine residue by five or more atoms, and

wherein the cyclic segment comprises an amino acid sequence having 80% or more sequence identity to the amino acid sequence IPRGDNFR (SEQ ID NO: 1), IPRGDSFA (SEQ ID NO: 170), VPRGDTFA (SEQ ID NO: 171), or TPRGDTFA (SEQ ID NO: 172).

2 . The cyclic peptide according to claim 1 , further comprising at least one of a first segment between the cyclic segment and an N-terminal of the cyclic peptide or a second segment between the cyclic segment and a C-terminal of the cyclic peptide, wherein the at least one of the first segment or the second segment comprises an amino acid residue having an immobilizing functional group in a side chain.

3 . The cyclic peptide according to claim 2 ,

wherein the immobilizing functional group is an amino group or a thiol group.

4 . The cyclic peptide according to claim 2 ,

wherein the amino acid residue having the immobilizing functional group in a side chain is selected from the group consisting of an L-lysine residue, a D-lysine residue, an L-cysteine residue, a D-cysteine residue, an L-homocysteine residue, and a D-homocysteine residue.

5 . The cyclic peptide according to claim 4 ,

wherein the amino acid residue having the immobilizing functional group in a side chain is selected from the group consisting of an L-lysine residue, a D-lysine residue, an L-cysteine residue, and a D-cysteine residue.

6 . The cyclic peptide according to claim 2 ,

wherein, in a case of being present, each of the first segment and the second segment has a length of 1 to 20 amino acid residues.

7 . The cyclic peptide according to claim 1 ,

wherein the cyclic peptide comprises a plurality of the cyclic segments, and amino acid sequences of the respective cyclic segments may be the same or different from each other.

8 . The cyclic peptide according to claim 7 ,

wherein the plurality of the cyclic segments are connected to each other by a connecting moiety having a length of 1 to 20 amino acid residues.

9 . The cyclic peptide according to claim 1 ,

wherein a total number of amino acid residues is 8 to 50.

10 . The cyclic peptide according to claim 1 ,

wherein the cyclic peptide is represented by Formula II′:

wherein in Formula II′,

X a represents the amino acid residue X a , X b represents the amino acid residue X b ;

X 8 , X 9 , X 10 and X 11 each independently represent any amino acid residue, where in a case where a plurality of X 8 's, X 9 's, X 10 's or X 11 's are present, the plurality of X 8 's, X 9 's, X 10 's or X 11 's may be the same or different from each other;

R N represents an N-terminal group; R C represents a C-terminal group;

X 6 and X 7 each independently represent an amino acid residue having an immobilizing functional group in a side chain, where in a case where a plurality of X 6 's or X 7 's are present, the plurality of X 6 's or X 7 's may be the same or different from each other;

p0 and q0 are integers and respectively satisfy 0≤p0≤15 and 0≤q0≤15;

t0 and u0 are integers and respectively satisfy 0≤t0≤5 and 0≤u0≤5;

v0 and w0 are integers and respectively satisfy 0≤v0≤5 and 0≤w0≤5; and

p0, q0, t0, u0, v0, and w0 further satisfy 0≤p0+q0+t0+u0+v0+w0≤39;

X t represents any amino acid residue, and in a case a plurality of X's are present, the plurality of X's may be the same or different from each other;

X 1 represents I, V, D, E, Y, L, T, or homotyrosine;

X 2 represents P, T, or S;

X 3 represents N, S, T, V, A or homoserine;

X 4 represents F, Y, or P;

X 5 represents R, D, E, A, T, S, or G;

v5 and v7 each independently represent an integer of 0 to 6; and

v6 represents 0 or 1.

11 . The cyclic peptide according to claim 10 ,

wherein the cyclic peptide satisfies at least one selected from the group consisting of the following (i) to (v):

(i) an amino acid residue represented by X 1 is I, V, or T;

(ii) an amino acid residue represented by X 2 is P;

(iii) an amino acid residue represented by X 3 is S or T;

(iv) an amino acid residue represented by X 4 is F; and

(v) v6 represents 1, and an amino acid residue represented by X 5 is A.

12 . A cell scaffold material comprising:

a base material; and

the cyclic peptide according to claim 1 .

13 . A cell separating material comprising:

a holding material; and

the cyclic peptide according to claim 1 .

14 . A medium comprising:

a culture component; and

the cyclic peptide according to claim 1 .