Patent ID: 8012488

Claim:
A polyoxyalkylene derivative represented by the following formula (1) wherein Z is a peptide residue consisting of 2 to 10 amino acid residues, wherein one or more amino acid residues have a side chain containing a functional group, OA is an oxyalkylene group having 2 to 4 carbon atoms, R is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, X 1 is a group containing a succinimide group, a maleimide group, an amino group, a carboxyl group, a carbonate group, an aldehyde group, a sulfonyl group, a thiol group, or a vinyl group, X 2 is a group containing a succinimide group, a maleimide group, an amino group, a carboxyl group, a carbonate group, an aldehyde group, a sulfonyl group, a thiol group, a vinyl group, or a hydroxyl group, Y and W are each independently a divalent group containing a group selected from the group consisting of —S—S— and —O—, wherein at least one Y and/or W moiety differs from the remaining Y and W moieties, n is an integer of 5-1000, m is an integer of 5-800, j 1 is an integer of 0-8, j 2 is an integer of 0- 8, k is an integer of 0-8, wherein 1≦j 1 +j 2 ≦12, 3≦k+j 1 +j 2 ≦12, 30≦(n×k)+(m×j 1 )≦2000.