ENGINEERING OF NEW BINDING SPECIFICITIES OF PROTEIN A

THE OBJECTIVE OF THIS RESEARCH IS TO USE PROTEIN ENGINEERING TO GENERATE STAPHYLOCOCCAL PROTEIN A VARIANTS THAT POSSESS STRONG BINDING AFFINITY FOR IMMUNOGLOBULIN SPECIES THAT ARE NOT SIGNIFICANTLY BOUND BY NATURAL PROTEIN A. THE EXPERIMENTAL PROGRAM WILL INVOLVE A SEQUENTIAL SERIES OF EXPERIMENTS OF INCREASING LEVELS OF DIFFICULTY ENCOMPASSING STRUCTURAL DESIGN, VARIANT CONSTRUCTION, AND TESTING OF IMMUNOGLOBULIN BINDING. BASED ON THE EXISTING PROTEIN A/IMMUNOGLOBULIN FC COCRYSTAL STRUCTURE, COMPUTER MODELING AND GENETIC ENGINEERING TECHNOLOGIES WILL BE USED TO DESIGN AND PRODUCE PROTEIN A VARIANTS WITH HIGH ENGINEERED AFFINITY FOR (1) HUMAN IGG3, (2) MOUSE IGG1, AND (3) HUMAN IGM FOR THE CLINICAL DIAGNOSTICS AND THERAPEUTICS MARKET. IF SUCCESSFUL, THIS MODIFICATION OF THE BINDING SPECIFICITY OF A PROTEIN-PROTEIN COMPLEX WILL BE A MILESTONE IN THE DEVELOPMENT OF PROTEIN ENGINEERING AND WILL ALSO SERVE AS A PREFACE TO THE ENGINEERING OF PROTEIN A VARIANTS THAT BIND OTHER IMMUNOGLOBULIN CLASSES, E.G., IGE, IGD, AND IGA. THE ENGINEERED AFFINITY PROTEIN FOR HUMAN IGM WILL HAVE UTILITY AS A DIAGNOSTIC REAGENT FOR ANTIGEN-SPECIFIC IGM AND AS A THERAPEUTIC IN EXTRACORPOREAL BLOOD FILTRATION FOR DISEASES INCLUDING CANCER AND AIDS.