Method for labeling of compounds
View Patent ↗The present invention relates to site-specific labeling of antibodies or fragments thereof with one or more reporter group(s) in a way that does not affect antigen binding. The method for labeling antibodies and/or fragments thereof, comprises the following steps a) providing an IgG binding protein, which comprises α-helix structures, with a photoactivatable group and at least one label; b) forming a mixture of said IgG binding protein and the antibodies and/or fragments to be labeled; and c) UV illuminating said mixture for site-specific labeling of said antibodies and/or fragments thereof. The IgG binding protein is preferably the Z domain of Protein A.
1. A method for labeling antibody including fragments thereof, comprising:
a) providing an IgG binding protein, which comprises α-helix structures, with a photoactivatable group and at least one label and providing antibody and/or fragment thereof to be labeled;
b) forming a mixture of said IgG binding protein and the antibodies and/or fragments to be labeled; and
c) UV illuminating said mixture for site-specific labeling of said antibody and/or fragments thereof;
wherein the IgG binding protein is a Z domain of Protein A comprising SEQ ID NO 1 in which Phe in position 5 has been exchanged for BPA (benzoylphenylalanine).
2. The method of claim 1 , wherein the photoactivatable group is selected from benzophenone which is part of benzoylphenylalanine;
tetrafluorophenyl azide; trifluoromethylphenyl diazirine or 4-azidophenyl.
3. The method of claim 1 , wherein the label is selected from the group consisting of a fluorescent compound, a member of an affinity pair, DNA, PNA, and a radioisotope.
4. The method of claim 1 , wherein the Z domain is labeled in position 58 of SEQ ID NO 1.
5. The method of claim 4 , wherein the Z domain is further labeled in position 39 of SEQ ID NO 1 by first replacing Ser with Lys.
6. The method of claim 1 , wherein the label is conjugated to a linker.
7. The method of claim 5 , wherein the label is biotin and the linker is PEG.
8. The method of claim 1 , wherein the fragment is an Fc fragment and said Fc fragment is labelled.
9. Antibodies and/or fragments thereof labelled according to claim 1 .