Characterization of a set of HIV-1 protease inhibitors using binding kinetics data from a biosensor-based screen

The interaction between 290 structurally diverse human immunodeficiency vir us type 1 (HIV-1) protease inhibitors and the immobilized enzyme was analyz ed with an optical biosensor, Although only a single concentration of inhib itor was used, information about the kinetics of the interaction could be o btained by extracting binding signals at discrete time points. The statisti cal correlation between the biosensor binding data, inhibition of enzyme ac tivity (K-i), and viral replication (EC50) revealed that the association an d dissociation rates for the interaction could be resolved and that they we re characteristic for the compounds. The most potent inhibitors, with respe ct to K-i and EC50 values, including the clinically used drugs, all exhibit ed fast association and slow dissociation rates. Selective or partially sel ective binders for HIV-1 protease could be distinguished from compounds tha t showed a general protein-binding tendency by using three reference target proteins. This biosensor-based direct binding assay revealed a capacity to efficiently provide high-resolution information on the interaction kinetic s and specificity of the interaction of a set of compounds with several tar gets simultaneously.