A 80-kDa subcomponent of complement C1, existing as a SERINE PROTEASE proenzyme in the intact complement C1 complex. When COMPLEMENT C1Q is bound to antibodies, the changed tertiary structure causes autolytic activation of complement C1r which is cleaved into two chains, A (heavy) and B (light, the serine protease), connected by disulfide bonds. The activated C1r serine protease, in turn, activates COMPLEMENT C1S proenzyme by cleaving the Arg426-Ile427 bond. No fragment is released when either C1r or C1s is cleaved.
Complement C1r has been studied across 20 research domains including 🦴 Bone & Joint, 🔬 Oncology, ❤️ Cardiovascular, 🔬 Inflammation, 🛡️ Immunity. The primary research focus is 🦴 Bone & Joint with 16% of studies addressing this area.
This evidence profile for Complement C1r is generated deterministically from 113 PubMed-indexed studies. All data is corpus-verified with Merkle proofs. BiohacksAI does not provide medical advice. Always consult a healthcare professional before starting any supplement regimen.
Data source: PubMed/MEDLINE (NLM). Corpus version: current. Patent pending (EVE-PAT-2026-001). © 2026 Organiq Sweden AB.