Verfahren zur Messung von Komponenten eines Lebenskörpers durch Gebrauch von Polypeptiden

摘要

A process is provided for measuring an analyte in a sample derived from a living body which comprises: reacting a sample derived from a living body with a reagent, which reagent comprises a combined product of a polypeptide having 3 to 30 acid residues derived from a strong acid and a substance having affinity for the analyte, separating the resulting complex, and determining the amount of the analyte in the sample on the basis of the amount of the complex. A polypeptide is provided which may be represented by the formula: A-(R<1>)m'-B wherein R<1>'s are, the same or different, independently an amino acid residue introducing a strong acid residue derived from a strong acid having a pKa of 3 or lower thereinto by binding to a reactive group of the amino acid residue, said reactive group being selected from a hydroxyl group, an amino group, an imino group and a thiol group; m' is an integer of 3 to 30; A is a hydrogen atom, a protective group of N-terminus or an acid residue derived from the strong acid; and B is a hydroxyl group or a protective group of C-terminus; excluding those polypeptides having 3 to 20 tyrosine sulfate residues.