However, the order of the binding sequence and binding affinities to the individual receptor subunits differ markedly between the two cytokines.
Mithramycin has affinity for the GGGCGG binding sequence, and effectively blocks the binding of Sp1 [24].
In these studies, it became obvious that the addition of a one to seven amino acid spacer to the CCK2R binding sequence can modify affinity, specificity, tumour uptake and stability of the peptides [14 17].
Individual antibodies must also screened for ADCC activity, as repertoires can contain antibodies with significant differences in apparent ADCC potency, despite being specific for the same antigen and sharing properties of identical Fc and framework sequences, and similar binding and affinity profiles (Griggs et al, unpublished data).
Therefore, zinc finger motifs offer an attractive framework for the design of novel DNA binding proteins, and such a DNA binding protein would be expected to possess a unique binding sequence with high specificity and affinity.
Predicting DNA binding sites and affinities from transcription factor sequence or structure is difficult; therefore, experimental data are required to link transcription factors to target sequences.
Nevertheless, these importance matrices still provide an intuitive means for researchers to visualize and interpret results, and thus gain insights into the design of a binding sequence with a desired binding affinity.
The red color indicates that the k-mer at the corresponding starting position in the 12-mer binding sequence contributes to low binding affinity (a large K d value), whereas the blue color indicates a contribution to high binding affinity.
The procedure can be used to infer the strongest binders for a given DNA or RNA binding protein, and the highest affinity binding sequences isolated through SELEX can have numerous research, diagnostic and therapeutic applications.
This process enriches the initial random library for higher binding affinity sequences, and the cycle is repeated until the molecules in the enriched pools converge on the highest affinity sequence.
