Provided herein are compositions and methods directed to soluble proteins which can selectively deliver modulators of complement activity. Targeted delivery of these modulators is accomplished by selectively mutating particular amino acids in a targeting protein portion of the composition corresponding to at least the first two N-terminal SCR domains of CR2. Depending on the particular combination of mutations introduced into the targeting portion, a complement activity modulator can be selectively delivered to particular ligands of CR2 at sites where complement system activation or suppression is desired.