Nanobodies: natural single-domain antibodies

Annu Rev Biochem. 2013;82:775-97. doi: 10.1146/annurev-biochem-063011-092449. Epub 2013 Mar 13.


Sera of camelids contain both conventional heterotetrameric antibodies and unique functional heavy (H)-chain antibodies (HCAbs). The H chain of these homodimeric antibodies consists of one antigen-binding domain, the VHH, and two constant domains. HCAbs fail to incorporate light (L) chains owing to the deletion of the first constant domain and a reshaped surface at the VHH side, which normally associates with L chains in conventional antibodies. The genetic elements composing HCAbs have been identified, but the in vivo generation of these antibodies from their dedicated genes into antigen-specific and affinity-matured bona fide antibodies remains largely underinvestigated. However, the facile identification of antigen-specific VHHs and their beneficial biochemical and economic properties (size, affinity, specificity, stability, production cost) supported by multiple crystal structures have encouraged antibody engineering of these single-domain antibodies for use as a research tool and in biotechnology and medicine.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Antibodies / chemistry*
  • Antibodies / genetics
  • Antibodies / immunology
  • Antibody Affinity
  • Biotechnology
  • Camelids, New World
  • Camelus / genetics
  • Camelus / immunology*
  • Immunoglobulin Heavy Chains / chemistry*
  • Immunoglobulin Heavy Chains / genetics
  • Immunoglobulin Heavy Chains / immunology
  • Single-Domain Antibodies / chemistry*
  • Single-Domain Antibodies / immunology


  • Antibodies
  • Immunoglobulin Heavy Chains
  • Single-Domain Antibodies