Purification of polypeptides

Abstract

This invention relates to a process for purifying a polypeptide, a capture tag useful for purifying a polypeptide and a periodate-cleavable amino acid derivative useful for purifying a polypeptide.

1 - 24 . (canceled) 
     
     
         25 . An amino acid derivative selected from
   T-L-CO—CR′(R″)—NH—CHR 1 —COOH     T-L-CR(OH)—CR′(R″)—NH—CHR 1 —COOH     T-L-CR(NH 2 )—CR′(R″)—NH—CHR 1 —COOH   wherein   T is a capture tag group capable of binding, with or without the participation of the —CR—(OH)—, —CR(NH 2 )— or —CO— group, with a purification matrix   L is a divalent linker moiety or may be absent   R 1  is a side chain of a naturally occurring amino acid   R, R′ and R″ are independently selected from hydrogen, alkyl, aralkyl, aryl and heterocyclic groups, and protected derivatives, salts and activated derivatives thereof.   
     
     
         26 . A protected amino acid derivative of the formula
   pg 1 -NH—CH 2 —CH(Opg 2 )—CH 2 (Npg 3 )—CHR 1 CO—OH   wherein   pg 1 , pg 2  and pg 3  are the same or different and are protecting groups compatible with solid phase peptide synthesis,   R 1  is the side chain of an amino acid and salts and activated derivatives thereof.   
     
     
         27 . A protected amino acid derivative of the formula
   pg 4 -Cys(pg 5 )-NH—CH 2 —CH 2 —CH(Opg 6 )-CH 2  N(pg 7 )-CHR 1 CO—OH   wherein   pg 4 , pg 5 , pg 6  and pg 7  are the same or different and are protecting groups compatible with solid phase peptide synthesis,   R 1  is the side chain of an amino acid and salts and activated derivatives thereof.   
     
     
         28 . A kit for purification of a polypeptide, the kit comprising an amino acid derivative according to  claim 25  and a purification matrix comprising aldehyde or ketone groups.