title: Purification of IgD from human serum--a novel application of recombinant M. catarrhalis IgD-binding protein (MID).
abstract: Moraxella catarrhalis IgD-binding protein (MID) is a multimeric outer membrane protein belonging to the family of autotransporters. The IgD-binding domain of MID is located between amino acids MID 962-1200 and binds to amino acids 198-224 of the IgD C(H)1 region. In the present study, we describe a method to purify IgD from serum with high levels of IgD using a two-step affinity chromatography process. The first step involves depletion of MID-specific antibodies of all classes from serum using the non-IgD-binding fragment MID(1000-1200). This step is followed by selective capture of IgD with MID(962-1200). Furthermore, we demonstrate that the eluted IgD is pure, intact and functional for use in downstream applications. Our approach reduces the non-specificity commonly associated with lectin-based IgD purification regimes that rely on glycosylation of the IgD molecule.
authors.affiliation: Medical Microbiology, Department of Laboratory Medicine, Lund University, Malmö University Hospital, SE-205 02 Malmö, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Samuelsson
authors.forename: Arne
authors.initials: A
authors.lastname: Forsgren
authors.forename: Kristian
authors.initials: K
authors.lastname: Riesbeck
mesh_terms: D018829:Adhesins, Bacterial / Q000276:immunology; D015153:Blotting, Western; D002846:Chromatography, Affinity / Q000379:methods*; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007072:Immunoglobulin D / Q000302:isolation & purification*; D011994:Recombinant Proteins / Q000276:immunology; D044967:Serum / Q000737:chemistry / Q000276:immunology*
chemical_list: D018829:Adhesins, Bacterial; C439616:IgD-binding protein MID, Moraxella catarrhalis; D007072:Immunoglobulin D; D011994:Recombinant Proteins