title: Rugged single domain antibody detection elements for Bacillus anthracis spores and vegetative cells.
abstract: Significant efforts to develop both laboratory and field-based detection assays for an array of potential biological threats started well before the anthrax attacks of 2001 and have continued with renewed urgency following. While numerous assays and methods have been explored that are suitable for laboratory utilization, detection in the field is often complicated by requirements for functionality in austere environments, where limited cold-chain facilities exist. In an effort to overcome these assay limitations for Bacillus anthracis, one of the most recognizable threats, a series of single domain antibodies (sdAbs) were isolated from a phage display library prepared from immunized llamas. Characterization of target specificity, affinity, and thermal stability was conducted for six sdAb families isolated from rounds of selection against the bacterial spore. The protein target for all six sdAb families was determined to be the S-layer protein EA1, which is present in both vegetative cells and bacterial spores. All of the sdAbs examined exhibited a high degree of specificity for the target bacterium and its spore, with affinities in the nanomolar range, and the ability to refold into functional antigen-binding molecules following several rounds of thermal denaturation and refolding. This research demonstrates the capabilities of these sdAbs and their potential for integration into current and developing assays and biosensors.
authors.affiliation: Naval Research Laboratory, Washington D. C., United States of America.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Walper
authors.forename: George P
authors.initials: GP
authors.lastname: Anderson
authors.forename: P Audrey
authors.initials: PA
authors.lastname: Brozozog Lee
authors.forename: Richard H
authors.initials: RH
authors.lastname: Glaven
authors.forename: Jinny L
authors.initials: JL
authors.lastname: Liu
authors.forename: Rachel D
authors.initials: RD
authors.lastname: Bernstein
authors.forename: Dan
authors.initials: D
authors.lastname: Zabetakis
authors.forename: Linwood
authors.initials: L
authors.lastname: Johnson
authors.forename: Jill M
authors.initials: JM
authors.lastname: Czarnecki
authors.forename: Ellen R
authors.initials: ER
authors.lastname: Goldman
mesh_terms: D000595:Amino Acid Sequence; D000881:Anthrax / Q000175:diagnosis; D000907:Antibodies, Bacterial / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D000915:Antibody Affinity / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology; D001408:Bacillus anthracis / Q000276:immunology*; D006801:Humans; D007118:Immunoassay; D007700:Kinetics; D008969:Molecular Sequence Data; D055550:Protein Stability; D016415:Sequence Alignment; D057127:Single-Chain Antibodies / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D013171:Spores, Bacterial / Q000276:immunology; D013696:Temperature
chemical_list: D000907:Antibodies, Bacterial; D057127:Single-Chain Antibodies