Figure 2
From: The production of antibody fragments and antibody fusion proteins by yeasts and filamentous fungi
Schematical representation of the structure of a conventional IgG, a heavy-chain IgG antibody and the variable heavy-chain antibody fragment (VHH) that can be generated of the latter. Heavy-chain antibodies found in llama and camel are only composed of heavy-chains and lack the light chain completely, as shown in this Figure. The antigen-binding domain consists of only the VH domain, which is referred to as VHH (variable heavy-chain antibody fragment), to distinguish it from a normal VH. The constant heavy-chain domains CH1, CH2 and CH3 are shown in yellow, the constant light-chain domain (CL) in green and the variable heavy-chain (VH or VHH) or light-chain (VL) domains in red and orange, respectively.