Download MendeleyRational Modification of Ligand-Binding Preference of Avidin by Circular Permutation and Mutagenesis.
Maatta, J.A.E., Airenne, T.T., Nordlund, H.R., Janis, J., Paldanius, T.A., Vainiotalo, P., Johnson, M.S., Kulomaa, M.S., Hytonen, V.P.(2008) Chembiochem 9: 1124
- PubMed: 18381715
- DOI: https://doi.org/10.1002/cbic.200700671
- Primary Citation of Related Structures:
2JGS - PubMed Abstract:
Chicken avidin is a key component used in a wide variety of biotechnological applications. Here we present a circularly permuted avidin (cpAvd4-->3) that lacks the loop between beta-strands 3 and 4. Importantly, the deletion of the loop has a positive effect on the binding of 4'-hydroxyazobenzene-2-carboxylic acid (HABA) to avidin. To increase the HABA affinity of cpAvd4-->3 even further, we mutated asparagine 118 on the bottom of the ligand-binding pocket to methionine, which simultaneously caused a significant drop in biotin-binding affinity. The X-ray structure of cpAvd4--> 3(N118M) allows an understanding of the effect of mutation to biotin-binding, whereas isothermal titration calorimetry revealed that the relative binding affinity of biotin and HABA had changed by over one billion-fold between wild-type avidin and cpAvd4-->3(N118M). To demonstrate the versatility of the cpAvd4-->3 construct, we have shown that it is possible to link cpAvd4-->3 and cpAvd5-->4 to form the dual-chain avidin called dcAvd2. These novel avidins might serve as a basis for the further development of self-organising nanoscale avidin building blocks.
Organizational Affiliation:
Institute of Medical Technology, University of Tampere, 33014 University of Tampere, Finland.
