PDBsum entry 3hmw

Immune system

PDB id: 3hmw

Contents

Protein chains

214 a.a. *

218 a.a. *

Metals

_CD ×2

Waters ×125

* Residue conservation analysis

PDB id:

3hmw

Name:

Immune system

Title:

Crystal structure of ustekinumab fab

Structure:

Ustekinumab fab light chain. Chain: l. Engineered: yes. Ustekinumab fab heavy chain. Chain: h. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Expressed in: homo sapiens. Expression_system_taxid: 9606. Expression_system_cell_line: hek 293. Other_details: papain digested from mab. Other_details: papain digested from mab

Resolution:

3.00Å R-factor: 0.231 R-free: 0.287

Authors:

J.Luo

Key ref:

J.Luo et al. (2010). Structural basis for the dual recognition of IL-12 and IL-23 by ustekinumab. J Mol Biol, 402, 797-812. PubMed id: 20691190

Date:

29-May-09 Release date: 09-Jun-10

Protein chain

No UniProt id for this chain

Struc: 214 a.a.

Protein chain

No UniProt id for this chain

Struc: 218 a.a.

J Mol Biol 402:797-812 (2010)

PubMed id: 20691190

Structural basis for the dual recognition of IL-12 and IL-23 by ustekinumab.

J.Luo, S.J.Wu, E.R.Lacy, Y.Orlovsky, A.Baker, A.Teplyakov, G.Obmolova, G.A.Heavner, H.T.Richter, J.Benson.

ABSTRACT

Interleukin (IL)-12 and IL-23 are heterodimeric proinflammatory cytokines that share a common p40 subunit, paired with p35 and p19 subunits, respectively. They represent an attractive class of therapeutic targets for the treatment of psoriasis and other immune-mediated diseases. Ustekinumab is a fully human monoclonal antibody (mAb) that binds specifically to IL-12/IL-23p40 and neutralizes human IL-12 and IL-23 bioactivity. The crystal structure of ustekinumab Fab (antigen binding fragment of mAb), in complex with human IL-12, has been determined by X-ray crystallography at 3.0 Å resolution. Ustekinumab Fab binds the D1 domain of the p40 subunit in a 1:1 ratio in the crystal, consistent with a 2 cytokines:1 mAb stoichiometry, as measured by isothermal titration calorimetry. The structure indicates that ustekinumab binds to the same epitope on p40 in both IL-12 and IL-23 with identical interactions. Mutational analyses confirm that several residues identified in the IL-12/IL-23p40 epitope provide important molecular binding interactions with ustekinumab. The electrostatic complementarity between the mAb antigen binding site and the p40 D1 domain epitope appears to play a key role in antibody/antigen recognition specificity. Interestingly, this structure also reveals significant structural differences in the p35 subunit and p35/p40 interface, compared with the published crystal structure of human IL-12, suggesting unusual and potentially functionally relevant structural flexibility of p35, as well as p40/p35 recognition. Collectively, these data describe unique observations about IL-12p35 and ustekinumab interactions with p40 that account for its dual binding and neutralization of IL-12 and IL-23.