6KDI

Antibody 64M-5 Fab including isoAsp in complex with dT(6-4)T

PDB DOI: 10.2210/pdb6KDI/pdb
NDB: 6KDI

Classification: IMMUNE SYSTEM
Organism(s): Mus musculus, synthetic construct
Mutation(s): No

Deposited: 2019-07-02 Released: 2019-12-18
Deposition Author(s): Yokoyama, H., Mizutani, R., Noguchi, S., Hayashida, N.
Funding Organization(s): Japan Society for the Promotion of Science

Experimental Data Snapshot

Method: X-RAY DIFFRACTION
Resolution: 2.70 Å
R-Value Free: 0.259
R-Value Work: 0.210

wwPDB Validation 3D Report Full Report

This is version 1.0 of the entry. See complete history.

Literature

Structural and biochemical basis of the formation of isoaspartate in the complementarity-determining region of antibody 64M-5 Fab.

Yokoyama, H., Mizutani, R., Noguchi, S., Hayashida, N.

(2019) Sci Rep 9: 18494-18494

PubMed: 31811216 Search on PubMedSearch on PubMed Central
DOI: 10.1038/s41598-019-54918-0
Primary Citation of Related Structures:
6KDH, 6KDI

PubMed Abstract:

The formation of the isoaspartate (isoAsp) is one of spontaneous degradation processes of proteins, affecting their stability and activity. Here, we report for the first time the crystal structures of an antibody Fab that contains isoAsp in the complementarity-determining region (CDR), along with biochemical studies to detect isoAsp. By comparing the elution profiles of cation-exchange chromatography, it was clarified that the antibody 64M-5 Fab is converted from the normal form to isoAsp form spontaneously and time-dependently under physiological conditions. The isoAsp residue was identified with tryptic peptide mapping, N-terminal sequencing, and the protein isoaspartyl methyltransferase assay. Based on the fluorescence quenching method, the isoAsp form of 64M-5 Fab shows a one order of magnitude lower binding constant for its dinucleotide ligand dT(6-4)T than the normal form. According to the structure of the isoAsp form, the conformation of CDR L1 is changed from the normal form to isoAsp form; the loss of hydrogen bonds involving the Asn28L side-chain, and structural conversion of the β-turn from type I to type II'. The formation of isoAsp leads to a large displacement of the side chain of His27dL, and decreased electrostatic interactions with the phosphate group of dT(6-4)T. Such structural changes should be responsible for the lower affinity of the isoAsp form for dT(6-4)T than the normal form. These findings may provide insight into neurodegenerative diseases (NDDs) and related diseases caused by misfolded proteins.

Related Citations:

Structures of the antibody 64M-5 Fab and its complex with dT(6-4)T indicate induced-fit and high-affinity mechanisms.
Yokoyama, H., Mizutani, R., Noguchi, S., Hayashida, N.
(2019) Acta Crystallogr F Struct Biol Commun 75: 80

Organizational Affiliation:

Division of Molecular Gerontology and Anti-Ageing Medicine, Department of Biochemistry and Molecular Biology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi, 755-8505, Japan. hayasida@yamaguchi-u.ac.jp.

Macromolecules

Find similar proteins by:

(by identity cutoff) | 3D Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Anti-(6-4) photoproduct antibody 64M-5 Fab (light chain)	A [auth L]	218	Mus musculus	Mutation(s): 0
Entity Groups
Sequence Clusters	30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Protein Feature View Expand
Reference Sequence

Find similar proteins by:

(by identity cutoff) | 3D Structure

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Anti-(6-4) photoproduct antibody 64M-5 Fab (heavy chain)	B [auth H]	221	Mus musculus	Mutation(s): 0
Entity Groups
Sequence Clusters	30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Protein Feature View Expand
Reference Sequence