| abstract |
A peptide of the following (I) or (II). (I) a peptide represented by the formula B, A-B, B-C or A-B-C in which A, B and C each is represented by the following (1), (2) and (3) and, when it is bonded to other object peptide, it is able to extent the half-life in plasma as compared with the object peptide where the physiological activity of the object peptide is still retained. (II) a peptide comprising a reversed sequence of the peptide of (I); a sequence which is represented by A-B in (I) and A or B is reversed; a sequence which is represented by B-C in (I) and B or C is reversed; or a sequence which is represented by A-B-C in (I) and A, B, C, A and B, B and C or A and C is reserved. (1) A is a peptide comprising 1 to 14 of any amino acid(s) (2) B is a peptide represented by the formula 1: (Wk-Xl-Y-Zm-Wn)-(Wo-Xp-Y-Zq-Wr)s (In the formula 1, W is a basic amino acid; X and Z are any amino acids; Y is an acidic amino acid; k is 1 or 2; l is an integer of 4 >= l >= 0; m is an integer of 2 >= m >= 0; 4 >= l + m >= 0; n is 1 or 2; o is 1 or 2; p is an integer of 4 >= p >= 0; q is an integer of 2 >= q >= 0; 4 >= p + q >= 0; r is 1 or 2; and s is 0 or 1.) (3) C is a peptide comprising 2 to 14 of any amino acids. |