Isolation of the new antigen receptor from wobbegong sharks, and use as a scaffold for the display of protein loop libraries

A naturally occurring NAR variable domain binds the Kgp protease from Porphyromonas gingivalis

“…The 12A-9 and 12A-14 NAR domains are clearly derived from functional shark cDNAs and show no similarity, beyond invariant regions in the underlying framework, to the antiKgp NARs isolated previously [9]. These earlier proteins have synthetic rather than naturally selected CDR3 loops and were not a⁄nity matured.…”

“…With an a⁄nity for the target antigen of V130 nM, these single domains have antigen speci¢city comparable to recombinant forms of the camelid V H H single domain antibodies, where the a⁄nity varies between 2 and 300 nM [5,6]. However, NARs encompass this a⁄nity in two, rather than three CDR loops, as the CDR2 region is severely truncated [3,9]. The cysteine residues seen within many NAR (and camelid) CDR loops are conserved in both proteins 12A-9 and 12A-14, and probably contribute to the antigen-binding a⁄nity by disulphide bond formation and structural stability.…”

Selection and Characterization of Single Domain Antibodies Specific for Bacillus anthracis Spore Proteins

“…As the name implies, the parental antibody and its antigen binding domain is formed from only the heavy chain; a product of several mutations that eliminate interaction with the light chain subunit [9]. Sharks also possess heavy chain antibodies termed IgNAR from which a type of sdAb, often referred to as V NAR , can be derived [10,11]. To obtain high affinity sdAbs, usually one starts with an immunized host animal to permit in vivo affinity maturation prior to isolating the animal's immune repertoire for further selection.…”

Nanobodies as novel agents for disease diagnosis and therapy

“…These structures lack the light chains of conventional Abs and are known as heavy-chain Abs (HCAbs). Although similar structures have also been identified in elasmobranch cartilaginous fish (sharks, rays, and skates), 13,14 most research has been performed on camelids because of their ease of handling and immunization. 15 Derived from evolutionary processes, HCAbs possess certain features that facilitate their further splitting to stable, soluble, and easily manipulated single-domain (sdAbs) formats, used to deliver a variety of derivatives.…”

“…[16][17][18] The number of publications on Camelidae HCAbs and Nbs has risen dramatically since 2008, totaling up to 1,210 original articles in the Web of Science ® database (Thomson Reuters, Philadelphia, PA, USA) published within 9 years (2004-2012) from 300 universities in 67 countries to cover the areas of molecular biology, immunology, hematology, and experimental medicine (Figure 1). The 10-year exploration phase, predominantly oriented to the elucidation of Nb structure and properties, [13][14][15][19][20][21][22][23][24] was quickly followed by a rapidly increasing exploitation phase (Figure 2). This fast transition was enabled by the existing technological frame that offered an established research environment in terms of accumulated knowledge, capital outlays, infrastructure, and available skills.…”