1F90

FAB FRAGMENT OF MONOCLONAL ANTIBODY (LNKB-2) AGAINST HUMAN INTERLEUKIN-2 IN COMPLEX WITH ANTIGENIC PEPTIDE

Summary for 1F90

• Entry DOI: 10.2210/pdb1f90/pdb
• Descriptor: FAB FRAGMENT OF MONOCLONAL ANTIBODY, ANTIGENIC NONAPEPTIDE, ... (4 entities in total)
• Functional Keywords: monoclonal antibody, antigen-binding fragment, interleukin-2, antigenic peptide, immune system
• Biological source: Mus musculus (house mouse); More
• Total number of polymer chains: 3
• Total formula weight: 49112.75

Authors

Afonin, P.V.,Fokin, A.V.,Tsigannik, I.N.,Mikhailova, I.Y.,Onoprienko, L.V.,Mikhaleva, I.I.,Ivanov, V.T.,Mareeva, T.Y.,Nesmeyanov, V.A.,Li, N.,Duax, W.L.,Pletnev, V.Z. (deposition date: 2000-07-06, release date: 2001-07-11, Last modification date: 2024-10-30)

Primary citation

Afonin, P.V.,Fokin, A.V.,Tsygannik, I.N.,Mikhailova, I.Y.,Onoprienko, L.V.,Mikhaleva, I.I.,Ivanov, V.T.,Mareeva, T.Y.,Nesmeyanov, V.A.,Li, N.,Pangborn, W.A.,Duax, W.L.,Pletnev, V.Z.
Crystal structure of an anti-interleukin-2 monoclonal antibody Fab complexed with an antigenic nonapeptide.
Protein Sci., 10:1514-1521, 2001

PubMed Abstract: The three-dimensional structure of the Fab fragment of a monoclonal antibody (LNKB-2) to human interleukin-2 (IL-2) complexed with a synthetic antigenic nonapeptide, Ac-Lys-Pro-Leu-Glu-Glu-Val-Leu-Asn-Leu-OMe, has been determined at 3.0 A resolution. In the structure, four out of the six hypervariable loops of the Fab (complementarity determining regions [CDRs] L1, H1, H2, and H3) are involved in peptide association through hydrogen bonding, salt bridge formation, and hydrophobic interactions. The Tyr residues in the Fab antigen binding site play a major role in antigen-antibody recognition. The structures of the complexed and uncomplexed Fab were compared. In the antigen binding site the CDR-L1 loop of the antibody shows the largest structural changes upon peptide binding. The peptide adopts a mostly alpha-helical conformation similar to that in the epitope fragment 64-72 of the IL-2 antigen. The side chains of residues Leu 66, Val 69, and Leu 70, which are shielded internally in the IL-2 structure, are involved in interactions with the Fab in the complex studied. This indicates that antibody-antigen complexation involves a significant rearrangement of the epitope-containing region of the IL-2 with retention of the alpha-helical character of the epitope fragment.

PubMed: 11468348
DOI: 10.1110/ps.3101

Experimental method

X-RAY DIFFRACTION (2.6 Å)