Bacteriophage Kinetic Affinity Analysis
CONTEXT
Ever increasing demands in sensitivity and specificity of biosensors have established a trend toward the use of multivalent bioreceptors. This trend has also been introduced in the field of bacteriophage affinity peptides, where the entire phage is used as a receptor rather than the individual peptides. Although this approach is gaining in popularity due to the numerous advantages, binding kinetics of complete phage particles is a challenge, notwithstanding being essential for the efficient design of such applications.
The main concern in existing biosensor platforms is the use of microfluidic channels which can clog with these filamentous phages. Rinsing procedures can last up to half a day and are at risk of producing faulty data.
The main concern in existing biosensor platforms is the use of microfluidic channels which can clog with these filamentous phages. Rinsing procedures can last up to half a day and are at risk of producing faulty data.
FOx SOLUTION
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The Fox Biosystems platform was applied to study the affinity and binding kinetics of phages displaying peptide libraries. By using either peptide expression on the p3 or on the p8 coat proteins, 26 different phage strains with densities of 5 up to more than 2000 peptides on a single virus particle were analyzed. The binding parameters (koff and kon) towards its target enhanced Green Fluorescent Protein (eGFP) were characterized.
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FULL ARTICLE
http://pubs.acs.org/doi/abs/10.1021/ac402192k
CONCLUSION
This study revealed a broad affinity range of phages for the target eGFP, indicating their potential to be used for applications with different requirements in binding kinetics (sensitive diagnostics, purification, inline monitoring). Moreover, detailed kinetic analysis clearly showed the correlation between the binding parameters and the density at which eGFP-peptides are being expressed. Consequently, although p3 and p8-based phages both revealed exceptionally high affinities for eGFP, two p8 phages were found to have the highest affinity with dissociation constants (Kd) in the femtomolar range.