Immunogen sequence: PNNFETTTVI TVPTGYRVKL VFQQFDLEPS EGCFYDYVKI SADKKSLGRF CGQLGSPLGN PPGKKEFMSQ GNKMLLTFHT DFSNEENGTI MFYKGFLAYY QAVDLDECAS RSKSGEEDPQ PQCQHLC. C1 component of human complement is a complex of three glycoproteins: C1q, C1r and C1s. C1r h