Novel applications of nanobodies

Camelid derived single domain peptides are a novel form of antibody which maintain the same antigen binding properties but have greater stability and smaller size than traditional antibody. These molecules can be conjugate with several chromophores, for instance with green fluorescent protein for cellular imaging applications.
A group from the University of Munich (German) applied its deepen knowledge about GFP modifications to nanobodies, this is the name of camelid peptides. The result was an improvement in GFP brightness modulation. By performing a phage display screening, they found out seven different molecules able recognize GFP and enhance or minimize its fluorescent signal. To validate the system, they produced a GFP- tagged oestrogen receptor and a nuclear binding enhancer nanobody, in presence of hormone the receptor moved into the nucleus and GFP signal increased five- fold its brightness. Several applications can be thought for this tool. For instance, nanobodies for each cellular compartment can be useful to determine how the protein of interest tagged with GFP change their position inside the cells in response to specific stimuli. Alternatively, protein- protein interaction can be studied because nanobody can bind one protein and after interaction with the second protein fluorescent signal can be modulated, as well as it should be possible to evaluate the duration of interaction self. A novel and flexible tool is now available for biologists.