3.4.21.41 ? x * 68000, SDS-PAGE 753085 3.4.21.41 ? x * 69500, enzyme fused to maltose binding protein, SDS-PAGE 753377 3.4.21.41 ? x * 75900, calculated from amino acid sequence 753377 3.4.21.41 ? x * 78000, calculated from amino acid sequence 753598 3.4.21.41 ? x * 88000, C1r zymogen, domain structure, overview 683195 3.4.21.41 dimer 2 * 83000, SDS-PAGE of reduced protein, gel filtration in 6 M guanidinium hydrochloride 81393 3.4.21.41 dimer 2 * 85000, the C1rbar subunits consist of one polypeptide chain of 56000 Da, A-chain, that is disulfide-linked to a 27000 Da B-chain, SDS-PAGE 81395 3.4.21.41 dimer CCP1 is essential to the assembly of the dimer, but formation of a stable dimer is not a prerequisite for self-activation 652176 3.4.21.41 dimer deletion of CCP1 domain from CCP1-CCP2-SP fragment results in the loss of the dimeric structure. Dimerization of C1r is not a prerequisite for autoactivation 652680 3.4.21.41 heteropentamer C1q, 2 * C1s, 2 * C1r 717805 3.4.21.41 homodimer 2 * 90000, component C1r, calculated from amino acid sequence 755267 3.4.21.41 additional information C1 complex structure 683195 3.4.21.41 additional information C1r and C1s pro-enzymes form a heterotetrameric structure that associates with the recognition molecule, C1q, in the C1 complex 732102 3.4.21.41 additional information C1rbar and the proenzyme C1r are noncovalent dimers, the subunit of C1r has a MW of 53000-85000 Da, SDS-PAGE 81403 3.4.21.41 additional information each C1r monomer consists of six domains, CUB1-EGF-CUB2-CCP1-CCP2-SP, i.e. an N-terminal CUB module, an EGF-like module, a second CUB module, two complement control modules CCP, and a serine protease domain SP. The three domains that constitute the catalytic fragment of C1r (CCP1-CCP2-SP) readily form head-to-tail dimers. The CUB1-EGF-CUB2 fragments of C1r also dimerize 732889 3.4.21.41 additional information on activation the single polypeptide chain of C1r is cleaved probably at a single position, the C1rbar subunits consist of 1 polypeptide chain of 56000 Da, A-chain, that is disulfide-linked to a 27000 Da B-chain 81395 3.4.21.41 additional information the C1 complex comprises two loosely interacting subunits, C1q and the Ca2+-dependent C1s-C1r-C1r-C1s tetramer. Binding of C1 to activator is mediated by C1q and triggers activation of proenzyme C1r into an active protease C1rbar, which in turn activates C1s, thereby initiating the classical pathway of complement 81390