Llama-derived single-domain antibodies for the detection of botulinum A neurotoxin

Abstract

Single-domain antibodies (sdAb) specific for botulinum neurotoxin serotype A (BoNT A) were selected from an immune llama phage display library derived from a llama that was immunized with BoNT A toxoid. The constructed phage library was panned using two methods: panning on plates coated with BoNT A toxoid (BoNT A Td) and BoNT A complex toxoid (BoNT Ac Td) and panning on microspheres coupled to BoNT A Td and BoNT A toxin (BoNT A Tx). Both panning methods selected for binders that had identical sequences, suggesting that panning on toxoided material may be as effective as panning on bead-immobilized toxin for isolating specific binders.All of the isolated binders tested were observed to recognize bead-immobilized BoNT A Tx in direct binding assays, and showed very little cross-reactivity towards other BoNT serotypes and unrelated protein. Sandwich assays that incorporated selected sdAb as capture and tracer elements Correspondence to: Ellen R. Goldman, ellen.goldman@nrl.navy.mil. Electronic supplementary material The online version of this article

Immunoreaction of a recombinant nanobody from camelid single domain antibody fragment with Acinetobacter baumannii

“…To date, many VHH phage libraries have been reported with the antibody affinities in the range of 10 29 to 10 210 . 23 In our study, the affinity of the nanobodies against recombinant Bap protein was 3.8× 10 28 M/L. Our data indicate that 20 mg of anti-Bap nanobody can effectively neutralize sixfold LD 50 of A. baumannii in Intraperitoneal injection in mice.…”

Antibodies against a synthetic peptide designed to mimic a surface area of the H chain of botulinum neurotoxin A

“…Methods have utilized for detection the toxin's proteolytic activity of [see for example Refs. [20][21][22][23][24][25][26], molecular biology techniques [27][28][29][30][31][32], various immunological methods relying mainly on anti-toxin Abs [33][34][35][36][37][38][39][40][41][42] or on Abs in combination with other tools [43][44][45]. It should be noted that toxin serotypes exhibit different degrees of structural homology and therefore their use as immunogens produces Abs with differing levels of cross-reactivity.…”

Isolation and characterization of malaria PfHRP2 specific VNAR antibody fragments from immunized shark phage display library

“…Interestingly, the pattern of enrichment was similar to the end titer of polyclonal IgNAR responses in vivo where the highest titers was rPfLDH-specific, rPfHRP2-specific, and followed by rPvAldolase-specific V NAR clones. From this point of view, it is postulated the immunization process is an important factor to generate the high affinity single domain clones [ 25 , 45 ]. In contrast to “naïve” antibody libraries, lesser rounds of panning cycles were needed to produce a highly specific signal which is in agreement with that reported from other immune phage display libraries [ 46 ].…”