C1sa

Complement C1s-A subcomponent

688 amino acids

C1s B chain is a serine protease that combines with C1q and C1r to form C1, the first component of the classical pathway of the complement system. C1r activates C1s so that it can, in turn, activate C2 and C4 (By similarity).

Belongs to the peptidase S1 family.

76.858 kDa

MWCLVLFSLLASFSAEPTMHGEILSPNYPQAYPNDVVKSWDIEVPEGFGIHLYFTHVDIEPSESCAYDSVQIISGGIEEGRLCGQKTSKSPNSPIIEEFQFPYNKLQVVFTSDFSNEERFTGFAAYYTAIDINECTDFTDVPCSHFCNNFIGGYFCSCPPEYFLHDDMRNCGVNCSGDVFTALIGEISSPNYPNPYPENSRCEYQIQLQEGFQVVVTMQREDFDVEPADSEGNCPDSLTFASKNQQFGPYCGNGFPGPLTIRTQSNTLGIVFQTDLMGQKKGWKLRYHGDPISCAKKITANSTWEPDKAKYVFKDVVKITCVDGFEVVEGHVSSTSYYSTCQSDGQWSNSGLKCQPVYCGIPDPIANGKVEEPENSVFGTVVHYTCEEPYYYMEHEEGGEYRCAANGRWVNDQLGIELPRCIPACGVPTEPFQVHQRIFGGQPAKIENFPWQVFFNHPRASGALINEYWVLTAAHVLEKISDPLMYVGTMSVRTTLLENAQRLYSKRVFIHPSWKKEDDPNTRTNFDNDIALVQLKDPVKMGPKVSPICLPGTSSEYNVSPGDMGLISGWGSTEKKVFVINLRGAKVPVTSLETCKQVKEENPTVRPEDYVFTDNMICAGEKGVDSCHGDSGGAFAFQVPNVTVPKFYVAGLVSWGKRCGTYGVYTKVKNYVDWILKTMQENSGPRKD