Applications

The SPRi-based array platform offers many applications beyond simply determining binding kinetics. The technology can be applied for real-time and label-free screening of most biomarkers and biological targets. An array format provides advantages such as multiplexed interaction monitoring, parallel analysis, minimal sample usage, rapid data collection, and quantitative results. Plexera and our customers have demonstrated many applications using the PlexArray platform. Below are some of the common applications of the PlexArray HT.

• Drug discovery
Affinity-based screening of small molecule microarrays enables researchers to identify interacting compounds and understand interaction kinetics, and the ability to regenerate and re-use arrays keeps cost points down. Plexera’s FDA+ Array permits rapid screening of FDA-approved compounds for potential drug repurposing.
• Drug optimization/in situ fragment discovery
Screening a target protein against immobilized libraries small molecules has been used to identify fragments with strong affinities to the target analyte. This information can be utilized along with medicinal chemistry to optimize drug compounds.
• Epitope mapping
Customized peptide arrays provide not only basic epitope mapping but also provide an ideal platform for identifying antigen modifications that alter antibody binding kinetics.
• PPI and protein complex characterization
Protein-protein interactions can be analyzed by using peptide arrays to identify regions of association, flowing one purified protein over an array of peptides representing a second protein. Order of complex assembly and kinetics of the various member interactions are possible through immobilizing individual proteins or peptides and sequentially flowing other members of a complex.
• Nucleotide recognition mapping
Nucleotide arrays and injections of DNA- or RNA-binding proteins yields binding kinetics for up to several thousand sequences in a single analysis. Competitive binding assays can further enhance an understanding of interactions and sequence specificity.
• Biomarker discovery
Collaborative and contract projects have used lectin and antibody arrays in biomarker discovery programs, examining changes on protein expression and/or post-translational modification during disease progression. Other arrays also hold potential for use in biomarker arrays, and the ability to multiplex array content to include a variety of ligands (proteins, antibodies, lectins, etc.) expands the power of this platform for discovery screens.
• Glycobiology discovery
Characterization of post-translational protein modifications through sample analysis over on lectin and glycan arrays can be used for biomarker discovery, antibody profiling, cell differentiation, disease progression, and more. Plexera’s Lectin Array detects the majority of known human glycan moieties.
• Hybridoma screening
Automated injections of hybridoma supernatants over a multiplexed array of target proteins and/or peptides as well as isotype indicators permits simultaneous isotyping and characterization of monoclonal antibody kinetics. Inclusion of non-targeted proteins such as serum proteins or related proteins against which antibody recognition is not desired further accelerates elimination of less-than-ideal hybridomas from the pipeline