Evaluating the conformation of recombinant domain I of β2-glycoprotein I and its interaction with human monoclonal antibodies

Autor: David S. Latchman, Ian Giles, Paul C. Driscoll, Anastasia Lambrianides, Anisur Rahman, Yiannis Ioannou, Charis Pericleous, David A. Isenberg, Diego Esposito, Acely Garza-Garcia, Jennifer A. Miles
Rok vydání: 2011
Předmět:
Models
Molecular
CL
cardiolipin
medicine.drug_class
DI
domain I of β2GPI
Immunology
Plasma protein binding
Domain I
Monoclonal antibody
Polymerase Chain Reaction
Article
law.invention
law
β2GPI
beta-2-glycoprotein I
medicine
Humans
Beta 2-Glycoprotein I
His6-tag
hexahistidine tag
NMR
nuclear magnetic resonance
Nuclear Magnetic Resonance
Biomolecular
Molecular Biology
Nuclear magnetic resonance spectroscopy
chemistry.chemical_classification
aPL
antiphospholipid antibodies
biology
Chemistry
Antiphospholipid antibodies
E. coli
Escherichia coli
Antibodies
Monoclonal
PL
phospholipids
Periplasmic space
Antiphospholipid Syndrome
VH
variable heavy chain of Ig
Molecular biology
Recombinant Proteins
Protein Structure
Tertiary
Beta-2-glycoprotein I
Amino acid
APS
antiphospholipid syndrome
Biochemistry
beta 2-Glycoprotein I
Antibodies
Antiphospholipid
HSQC
15N
1H-heteronuclear single quantum correlation
VL
variable light chain of Ig
biology.protein
Recombinant DNA
Binding Sites
Antibody
Antibody
Heteronuclear single quantum coherence spectroscopy
Protein Binding
Zdroj: Molecular Immunology
ISSN: 0161-5890
DOI: 10.1016/j.molimm.2011.07.024
Popis: Highlights ► Bacterial expressed human recombinant DI has a structure consistent with that of DI in the published β2GPI crystal structure. ► Mutating residues D8/D9 and R39 do not alter the overall DI protein fold but cause local changes in surface contour. ► Monoclonal aPL-derived antibodies and DI of β2GPI interactions are influenced by specific arginine residues in aPL and particular epitopes in DI.
Pathogenic antiphospholipid antibodies (aPL) cause the antiphospholipid syndrome (APS) by interacting with domain I (DI) of beta-2-glycoprotein I (β2GPI). The aPL/β2GPI complex then exerts pathogenic effects on target cells. We previously described periplasmic bacterial expression of native and mutated variants of DI, and reported the presence of immunodominant epitopes at positions 8–9 (D8/D9) and position 39 (R39). Mutations at these positions strongly influenced the ability of recombinant DI to bind patient-derived IgG aPL and to inhibit pathogenic effects of these aPL in a mouse model of APS. We now describe an improved cytoplasmic bacterial expression system allowing higher yield of DI. We demonstrate that the nuclear magnetic resonance (NMR) spectra of a 15N,13C-isotope-labelled sample of the recombinant DI protein exhibit properties consistent with the structure of DI in crystal structure of intact β2GPI. Mutations at D8/D9 and R39 had limited impact on the NMR spectrum of DI indicating maintenance of the overall fold of the DI domain. We investigated interactions between five variants of DI and ten monoclonal human IgG antibodies, all derived from the IgG aPL antibody IS4 by sequence manipulation and in vitro expression. Arginine residues at positions 100 and 100g in IS4VH CDR3 play a particularly important role in binding to DI, but this is unlikely to be due to electrostatic interactions with negatively charged amino acids on DI. Both the strength of binding to DI and the ability to discriminate different DI variants varies between the different IgG antibodies tested. There was no simple relationship between these binding properties and antibody pathogenicity.
Databáze: OpenAIRE
Externí odkaz: