Therapeutic antibodies: Discovery and development using the ProteOn XPR36 biosensor interaction array system.

Therapeutic monoclonal antibodies are becoming a significant and rapidly growing class of therapeutic pharmaceuticals. Their discovery and development requires fast and high-throughput methodologies for screening and selecting appropriate candidate antibodies having high affinity for the target as well as high specificity and low cross-reactivity. This study demonstrates the use of the ProteOn XPR36 protein interaction array system and its novel approach, termed One-Shot Kinetics, for the rapid screening and selection of high-affinity antibodies. This approach allows multiple quantitative protein binding analyses in parallel, providing association, dissociation, and affinity constants for several antibodies or supernatants simultaneously in one experiment. We show that the ProteOn XPR36 system is a valuable tool for use across multiple stages of the therapeutic antibody discovery and development process, enabling efficient and rapid screening after panning, affinity maturation, assay validation, and clone selection.

Parallel kinetic analysis and affinity determination of hundreds of monoclonal antibodies using the ProteOn XPR36.

The production of antibodies for diagnostic and therapeutic applications is a major focus for biotechnology and pharmaceutical companies, and it requires the development of fast, high-throughput methodologies for screening and selecting appropriate candidate antibodies for development. These candidates must have very high affinity for the target as well as high specificity and low cross-reactivity. This study demonstrates the use of the ProteOn XPR 36 protein interaction array system for the rapid screening and selection of high-affinity antibodies--"one-shot" kinetics. This approach allows multiple quantitative protein binding analyses in parallel, providing association, dissociation, and affinity constants for several antibodies simultaneously in one experiment. We have used this new methodology to screen hundreds of monoclonal supernatants containing antibodies against two proteins of potential clinical interest: human interleukin 12 (IL-12) and a human hemoglobin (Hb) variant. In fact, approximately 250 supernatants raised against each antigen were screened in approximately 17 h, providing several high-affinity candidate monoclonal antibodies for each of these antigens.

Exploring "one-shot" kinetics and small molecule analysis using the ProteOn XPR36 array biosensor.

A ProteOn XPR36 parallel array biosensor was used to characterize the binding kinetics of a set of small molecule/enzyme interactions. Using one injection with the ProteOn's crisscrossing flow path system, we collected response data for six different concentrations of each analyte over six different target protein surfaces. This "one-shot" approach to kinetic analysis significantly improves throughput while generating high-quality data even for low-molecular-mass analytes. We found that the affinities determined for nine sulfonamide-based inhibitors of the enzyme carbonic anhydrase II were highly correlated with the values determined using isothermal titration calorimetry. We also measured the temperature dependence (from 15 to 35 degrees C) of the kinetics for four of the inhibitor/enzyme interactions. Our results illustrate the potential of this new parallel-processing biosensor to increase the speed of kinetic analysis in drug discovery and expand the applications of real-time protein interaction arrays.