Use of urea variants as affinity ligands
View Patent ↗The present invention relates to an IgG-binding compound, which more specifically has affinity for human IgGs of κ-type and functional derivatives thereof. More specifically, the compound according to the invention comprises an N,N-alkylated urea moiety located between an aromatic part and another part, which is a linear or cyclic substituted or unsubstituted aliphatic group. The compound binds to a pocket-shaped binding site present on all human IgG κ-Fabs, which site is located between the two domains (CH1 and CL) of its constant part. Accordingly, the compound according to the invention is a ligand for human IgGs of κ-type, and consequently, the invention also relates to a separation matrix for affinity chromatography, which matrix comprises said compound, as well as to other uses of the compound.
1. A separation matrix for affinity chromatography, comprising ligands coupled to a support, wherein the majority of the ligands are the compounds of formula (I)
wherein
R 1 is CH 3 or CH 2 CH 3 ;
R 2 is a phenyl group that has been substituted with Cl in meta and para position;
R 3 is H, CH 3 or CH 2 CH 3 ; and
R 4 is a linear or cyclic aliphatic group,
or, wherein
R 1 and R 2 are as stated above while R 3 and R 4 are parts of a 4- to 6-membered cyclic entity,
and which compound has affinity for human IgG of κ-type;
further wherein said ligands are coupled to said support through the group R 4 .
2. The separation matrix of claim 1 , wherein the ligands have been coupled to the support via linkers.
3. The separation matrix of claim 1 , wherein the support is a porous polymeric particle.
4. A system suitable for affinity chromatography, comprising the separation matrix of claim 1 packed in a column.
5. The separation matrix of claim 1 , wherein the compounds of formula (I) is an affinity ligand with affinity for the constant region of a Fab fragment of human IgG of κ-type.
6. The separation matrix of claim 1 , wherein R 1 is CH 3 .
7. The separation matrix of claim 1 , wherein R 1 is CH 3 ; and R 3 and R 4 are parts of a cyclic 5-membered group.
8. The separation matrix of claim 7 , wherein the cyclic 5-membered entity is substituted in a position directly adjacent to N with a C(O)—O—CH3 group.
9. The separation matrix of claim 1 , wherein said compounds of formula (I) are capable of binding to the constant region of a human IgG of κ-type, or a functional derivative thereof, with a binding constant of at least 10 −3 M.
10. The separation matrix of claim 1 , wherein said compounds of formula (I) are capable of binding to the constant region of a human IgG of κ-type, or a functional derivative thereof, via a binding pocket-defined by the structure coordinates of the amino acids as shown in FIG. 6 .