The goal of this project is to understand at the molecular level the sequence of events in the activation of complement by immune complexes. A variety of mutant C1s's (a subunit of C1, the first component of the complement system) will be expressed in the baculovirus insect cell system. Attempts will be made to crystallize these mutant proteins for structure studies. Monoclonal antibodies will be employed as probes of the structure of C1 and the manner in which the subunits Cls, Clr and Clq are combined. Electron microscopy will be also used in determining the locations of binding sites of antibody to Clr and Cls.
