PDBsum entry 2hwz

Immune system

PDB id: 2hwz

Contents

Protein chains

210 a.a. *

227 a.a. *

Waters ×357

* Residue conservation analysis

PDB id:

2hwz

Name:

Immune system

Title:

Fab fragment of humanized anti-viral antibody medi-493 (synagis tm)

Structure:

Immunoglobulin fab light chain. Chain: l. Engineered: yes. Other_details: humanized mouse antibody medi-493 anti-respiratory syncytial virus antibody. Immunoglobulin fab heavy chain. Chain: h. Engineered: yes. Other_details: humanized mouse antibody medi-493 anti-respiratory

Source:

Homo sapiens, mus musculus. Organism_taxid: 9606, 10090. Organism_taxid: 9606, 10090

Resolution:

1.80Å R-factor: not given

Authors:

B.Braden

Key ref:

Z.Wei et al. (2007). Identification of a single tryptophan residue as critical for binding activity in a humanized monoclonal antibody against respiratory syncytial virus. Anal Chem, 79, 2797-2805. PubMed id: 17319649

Date:

02-Aug-06 Release date: 14-Aug-07

Protein chain

No UniProt id for this chain

Struc: 210 a.a.

Protein chain

No UniProt id for this chain

Struc: 227 a.a.

Anal Chem 79:2797-2805 (2007)

PubMed id: 17319649

Identification of a single tryptophan residue as critical for binding activity in a humanized monoclonal antibody against respiratory syncytial virus.

Z.Wei, J.Feng, H.Y.Lin, S.Mullapudi, E.Bishop, G.I.Tous, J.Casas-Finet, F.Hakki, R.Strouse, M.A.Schenerman.

ABSTRACT

We have identified a single tryptophan (Trp) residue responsible for loss of binding and biological activity upon ultraviolet (UV) light irradiation in MEDI-493, a humanized monoclonal antibody (MAb) against respiratory syncytial virus (RSV). This finding provides a better understanding of structure-function relationship in a 150-kDa protein. Irradiation of MEDI-493 with UV light resulted in spectral changes typical of Trp photoproducts and in a progressive loss of MEDI-493 binding and biological activity as measured by ELISA, Biacore, and cell-based assays. Mass spectrometric characterization of the proteolytic peptides generated from the UV irradiated MEDI-493 confirmed that most methionine (Met) and a few Trp residues were oxidized to various extents upon exposure to UV light. Among Trp residues, only Trp-105, containing the most solvent-exposed indole moiety in MEDI-493 and residing in a complementary-determining region (CDR) of the heavy chain, was significantly oxidized. When bound to a synthetic antigenic peptide, MEDI-493 showed significant resistance toward binding activity loss during UV irradiation. A second MAb (MEDI-524) with Trp-105 replaced by phenylalanine (Phe) showed a similar pattern of Met oxidation, but no loss of binding and biological activity following irradiation. Treatment of both MAbs with Met- and Trp-specific oxidizing reagents showed that oxidation of Trp-105 correlated with the activity loss, whereas Met oxidation did not affect the activity. These results demonstrate that Trp-105 in MEDI-493 is responsible for the UV light-induced effects.