Information on EC 3.4.21.41 - complement subcomponent C1r

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The expected taxonomic range for this enzyme is: Tetrapoda

EC NUMBER
COMMENTARY
3.4.21.41
-
RECOMMENDED NAME
GeneOntology No.
complement subcomponent C1r
-
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
Selective cleavage of Lys(or Arg)-/-Ile bond in complement subcomponent C1s to form C_overbar_1s_ (EC 3.4.21.42)
show the reaction diagram
EC 3.4.21.42
-
-
-
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
hydrolysis of peptide bond
-
-
endopeptidase
-
SYNONYMS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
activated complement C1r
-
-
-
-
C1r
-
factor XII fragment can activate C1r subcomponent of C1
C1r protease
-
C1r serine protease
-
-
C1rbar-esterase
-
-
-
-
complement C1r, activated
-
-
-
-
complement protease C1r
-
-
complement subcomponent 1r
-
CUB
-
complement C1r/C1s-sea urchin epidermal growth factor-BMP1
proteases C1r
-
serine protease C1r
-
-
xolloid
-
-
CAS REGISTRY NUMBER
COMMENTARY
80295-69-8
-
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
evolution
-
binding residues are conserved in the CUB1 domains of C1r, MASP-1/-3, and MASP-2, indicating that the interaction mechanism is conserved in initiating complexes of the lectin and classical pathways
metabolism
-
C1r and C1s pro-enzymes form a heterotetrameric structure that associates with the recognition molecule, C1q, in the C1 complex
metabolism
-
hexameric complement C1q is a versatile recognition protein that senses a wide variety of immune and nonimmune ligands, including pathogens and altered self components, and triggers the classical complement pathway through activation of its associated proteases C1r and C1s, EC 3.4.21.42. Residues LysB61 and LysC58 each play a key role in the interaction with C1s-C1r-C1r-C1s, with LysA59 being involved to a lesser degree
physiological function
-
the large multicomponent assembly C1 complex, binds to immune complexes, protein modulators (e.g., C-reactive protein), and polyanionic structures on pathogens to initiate complement activation. Binding to pathogens induces a conformational change that drives activation of the zymogen proteases in stepwise fashion: C1r first autoactivates, then activates C1s. C1s subsequently cleaves substrates C4 and C4b-bound C2, to form the C3 convertase (C4b2a), the downstream component of the reaction cascade
physiological function
-
C1r is a zymogen, activation of C1 occurs when the C1q subcomponent binds to a pathogen via its globular heads resulting in autolytic activation of C1r followed, in turn, by C1r-mediated activation of C1s
metabolism
-
complement is an important part of the immune system. It is initiated through three different pathways known as the classical, lectin, and alternative pathway. The multimolecular C1 complex of the classical pathway consists of a subcomponent, C1q, which binds to a tetramer comprising two C1r and two C1s proteases, EC 3.4.21.41 and EC 3.4.21.42, respectively
additional information
-
subsite profiling of human C1r using a phage display library with a fixed P1 arginine, specificity determinants, overview. Gln and Ile residues at P2 and P1', respectively, are important for cleavage of phage displayed substrates, the enzyme displays considerable specificity at every position apart from P4, P3', and P4'
additional information
-
the large multicomponent assembly C1 complex is composed of a recognition subcomponent, C1q (460 kDa), and two serine protease subcomponents, C1r (90 kDa) and C1s (80 kDa) in a 1:2:2 ratio, with an overall molecular mass of about790 kDa. C1r is a modular protease with two N-terminal complement C1r/C1s, Uegf and bone morphogenetic protein-1(CUB) domains, separated by an epidermal growth factor (EGF)-ike domain, followed by two complement control modules (CCP) and a C-terminal serine protease (SP) domain
additional information
-
the C1s/C1r/C1r/C1s tetramer forms a complex with C1q by interacting with the stems. C1r is a homologous multidomain protease containing 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. Interaction analysis and structure-function relationship, formation of the C1 complex, molecular dynamics simulations and thermodynamics, detailed overview
SUBSTRATE
PRODUCT                      
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
acetyl-Arg methyl ester + H2O
acetyl-Arg methanol
show the reaction diagram
-
-
-
?
acetyl-Gly-Lys-methyl ester + H2O
?
show the reaction diagram
-
-
-
-
?
benzyloxycarbonyl-Gly-Arg-thiobenzyl ester + H2O
?
show the reaction diagram
-
-
-
-
?
Benzyloxycarbonyl-Lys-thiobenzyl ester + H2O
?
show the reaction diagram
-
-
-
-
?
chordin + H2O
?
show the reaction diagram
-
C-terminal domains CUB1 and CUB2 are required for the ventralizing activity of Xld and for its ability to cleave chordin
-
-
?
complement C1q zymogen + H2O
active complement C1q + ?
show the reaction diagram
-
no or reduced activity with substrate mutants K59A, K61A, K58A, and K58A/K59A/K61A
-
?
complement component C1s
?
show the reaction diagram
-
-
-
-
-
complement component C1s
?
show the reaction diagram
-
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
-
-
-
complement component C1s
?
show the reaction diagram
-
regulation of the synthesis
-
-
-
complement component C1s
?
show the reaction diagram
-
activates the proenzyme form of C1s by limited proteolysis
-
-
-
complement component C1s + H2O
complement component C1sbar
show the reaction diagram
-
-
-
?
complement component C1s + H2O
complement component C1sbar
show the reaction diagram
-
-
-
?
complement component C1s + H2O
complement component C1sbar
show the reaction diagram
-
cleavage of a single Arg-Ile or Lys-Ile bond in C1s
-
?
complement component C1s + H2O
complement component C1sbar
show the reaction diagram
-
cleavage of a single Arg-Ile bond in the sequence Lys-Gln-Arg-Ile-Ile-Gly
-
?
complement component C1s + H2O
complement component C1sbar
show the reaction diagram
-
C1rbar does not hydrolyze any amino acid ester tested nor any protein substrate except subcomponent C1s
-
?
complement component C1s + H2O
complement component C1sbar
show the reaction diagram
-
C1R and its activated fragments all cleave C1s, in the order of increasing efficiency: C21r, CCP1/2-SP, CCP2-SP. CCP1 is not involved in C1s recognition
-
?
complement component C1s + H2O
activated complement component C1s + ?
show the reaction diagram
-
the enzyme is part of the Ca2+-dependent tetramer C1s-C1r-C1r-C1s, termed as C1 complex, which is associated with the recognition molecule C1q, autoactivation of C1r, which then activates proenzyme C1s through cleavage at an Arg-Ile bond in the serine domain, C1r is active in the classical pathway of the complement system
-
?
complement component C1s + H2O
activated complement component C1s + ?
show the reaction diagram
-
the enzyme is part of the Ca2+-dependent tetramer C1s-C1r-C1r-C1s, termed as C1 complex, which is associated with the recognition molecule C1q, autoactivation of C1r, which then activates proenzyme C1s through cleavage at an Arg-Ile bond in the serine domain, C1r is active in the classical pathway of the complement system
-
?
complement component C1s + H2O
activated complement component C1s + ?
show the reaction diagram
-
the enzyme is part of the Ca2+-dependent tetramer C1s-C1r-C1r-C1s, termed as C1 complex, which is associated with the recognition molecule C1q, autoactivation of C1r, which then activates proenzyme C1s through cleavage at an Arg-Ile bond in the serine domain, C1r is active in the classical pathway of the complement system, interaction anaylsis of the C1 complex and regulatory proteins, overview
-
?
complement component C1s + H2O
activated complement component C1s + ?
show the reaction diagram
-
C1r cleaves proenzyme C1s at an Arg-Ile bond in the serine domain
-
?
complement component C1s + H2O
activated complement component C1s + ?
show the reaction diagram
-
C1r cleaves proenzyme C1s at an Arg-Ile bond in the serine domain
-
?
complement component C1s + H2O
activated complement component C1s + ?
show the reaction diagram
-
C1r cleaves proenzyme C1s at an Arg-Ile bond in the serine domain, enzyme-product binding structure, overview
-
?
N-acetyl-Gly-Lys methyl ester + H2O
N-acetyl-Gly-Lys + methanol
show the reaction diagram
-
-
-
?
N-acetyl-Gly-Lys methyl ester + H2O
N-acetyl-Gly-Lys + methanol
show the reaction diagram
-
-
-
?
N-acetyl-Gly-Lys methyl ester + H2O
N-acetyl-Gly-Lys + methanol
show the reaction diagram
-
-
-
?
N-acetyl-Gly-Lys methyl ester + H2O
N-acetyl-Gly-Lys + methanol
show the reaction diagram
-
-
-
?
N-benzyloxycarbonyl-Gly-Arg thiobenzyl ester + H2O
?
show the reaction diagram
-
-
-
-
?
N-carbobenzoxy-Lys-p-nitrophenyl ester + H2O
N-carbobenzoxy-Lys + 4-nitrophenyl
show the reaction diagram
-
-
-
?
N-carbobenzoxy-Lys-p-nitrophenyl ester + H2O
N-carbobenzoxy-Lys + 4-nitrophenyl
show the reaction diagram
-
-
-
?
N-carbobenzoxy-Tyr-p-nitrophenyl ester + H2O
N-carbobenzoxy-Tyr + 4-nitrophenol
show the reaction diagram
-
-
-
?
zymogen C1s + H2O
active protease C1s + ?
show the reaction diagram
-
-
-
?
zymogen C1s + H2O
active C1s protease + ?
show the reaction diagram
-
the enzyme is active with the substrate fragment consisting of complement control protein domains, CCP1 and CCP2, plus serine protease domain of wild-type and mutant Q462N, Q462G, I464A, and Q462N/I464A forms of C1s, mutant Q462N/I464A substrate gives very low activity
-
?
zymogen C1s + H2O |
active C1s protease + ?
show the reaction diagram
-
-
-
?
MASP-3 K448Q zymogen + H2O
active MASP-3 protein + ?
show the reaction diagram
-
poor activity with the wild-type MASP-3
-
?
additional information
?
-
-
the ability of autoactivation of C1r and C1s cleavage activity is an inherent property of the SP domain
-
-
?
additional information
?
-
-
the enzyme recognizes the a short collagen-like peptide containing the sequence Hyp-Gly-Lys-Leu-Gly-Pro
-
-
-
additional information
?
-
-
the residues found in the activation loop of the zymogens capable of being activated by enzyme C1r play a major role in recognition of the active site of enzyme C1r
-
-
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
complement C1q zymogen + H2O
active complement C1q + ?
show the reaction diagram
-
-
-
?
complement component C1s
?
show the reaction diagram
-
-
-
-
-
complement component C1s
?
show the reaction diagram
-
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
-
-
-
complement component C1s
?
show the reaction diagram
-
regulation of the synthesis
-
-
-
complement component C1s
?
show the reaction diagram
-
activates the proenzyme form of C1s by limited proteolysis
-
-
-
complement component C1s + H2O
activated complement component C1s + ?
show the reaction diagram
-
the enzyme is part of the Ca2+-dependent tetramer C1s-C1r-C1r-C1s, termed as C1 complex, which is associated with the recognition molecule C1q, autoactivation of C1r, which then activates proenzyme C1s through cleavage at an Arg-Ile bond in the serine domain, C1r is active in the classical pathway of the complement system
-
?
complement component C1s + H2O
activated complement component C1s + ?
show the reaction diagram
-
the enzyme is part of the Ca2+-dependent tetramer C1s-C1r-C1r-C1s, termed as C1 complex, which is associated with the recognition molecule C1q, autoactivation of C1r, which then activates proenzyme C1s through cleavage at an Arg-Ile bond in the serine domain, C1r is active in the classical pathway of the complement system
-
?
complement component C1s + H2O
activated complement component C1s + ?
show the reaction diagram
-
the enzyme is part of the Ca2+-dependent tetramer C1s-C1r-C1r-C1s, termed as C1 complex, which is associated with the recognition molecule C1q, autoactivation of C1r, which then activates proenzyme C1s through cleavage at an Arg-Ile bond in the serine domain, C1r is active in the classical pathway of the complement system, interaction anaylsis of the C1 complex and regulatory proteins, overview
-
?
zymogen C1s + H2O
active protease C1s + ?
show the reaction diagram
-
-
-
?
zymogen C1s + H2O |
active C1s protease + ?
show the reaction diagram
-
-
-
?
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
Ca2+
-
binding of four Ca2+ per enzyme dimer
Ca2+
-
the NH2-terminal alpha fragment of the enzyme contains one high affinity Ca2+ binding site
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
3-alkoxy-4-chloro-7-guanidinoisocoumarin
-
-
4-chloro-3-[3-isothiureidopropoxyl]isocoumarin
-
-
-
4-Nitrophenyl-4-guanidinobenzoate
-
-
C1 inhibitor
-
during complex formation, C1 inhibitor dissociates C1r and C1s from the activated C1 macromolecule, a process that is determined primarily by the interaction with C1r
-
C1 inhibitor
-
-
-
C1-inhibitor
-
regulates the classical and the lectin complement pathway inhibiting complement components C1r and C1s, and MASP-2, factor XIa, Factor XIIa, and plasma kallikrein, mechanism, overview
-
C1bar-inhibitor
-
Ca2+ decreases the rate at which C1rbar complexes with C1bar-inhibitor. C1rbar-(C1bar-inhibitor) interaction is accelerated by heparin. Flufenamic acid inhibits the action of the inhibitor
-
C1bar-inhibitor
-
irreversible
-
C1bar-inhibitor
-
kinetics of the reaction between inhibitor and enzyme
-
C1INH
-
sole inhibitor of the activated proteases C1r and C1s. Hereditary angioedema results from functional deficiency of the C1 inhibitor (C1INH) protein, which plays a key role in the classical pathway of complement activation
-
Ca2+
-
reaction with C1s
calreticulin
-
prevents C1 formation
-
dichloroisocoumarin
-
-
diisopropyl fluorophosphate
-
-
NaCl
-
above 200 mM
p-amidinophenylmethylsulfonyl fluoride
-
-
-
p-tosyl-Lys-chloromethyl ketone
-
-
phenylmethylsulfonyl fluoride
-
-
polyanethol sulfonate
-
-
Leupeptin
-
competitive
additional information
-
specific c-Jun amino-terminal kinase inhibitor and the MEK-1 inhibitor PD98059 do not regulate C1r mRNA expression, whereas JSH-23, which inhibits nuclear translocation of NF-kappaB decreases C1r expression selectively in MEF-2 cells
-
additional information
-
above 0.0005 mM C1rbar the enzyme aggregates with loss of activity
-
additional information
-
high ionic strength inhibits
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
additional information
-
the recognition molecule C1q to the C1 complex triggers its autoactivation via C1r, the C-reactive protein, CRP, activates the C1 complex by binding to C1q
-
additional information
-
regulation of C1r by low-density lipoprotein receptor-related protein 1
-
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
20
acetyl-Gly-Lys methyl ester
-
-
0.000022
zymogen C1s
-
pH 7.4, 37C, substrate is a fragment consisting of complement control protein domains, CCP1 and CCP2, plus serine
-
0.000062
MASP-3 K448Q zymogen
-
pH 7.4, 37C
-
additional information
additional information
-
activated C1r and its wild-type CCP1/2-SP and CCP2-SP fragments all cleave acetyl-Gly-Lys-methyl ester with KM-values ranging from 1.3 mM to 2.1 mM
-
additional information
additional information
-
KM-values of the C1r fragments with benzyloxycarbonyl-Lys-thiobenzyl ester or benzyloxycarbonyl-Gly-Arg-thiobenzyl ester as substrate
-
additional information
additional information
-
kinetic interaction anaylsis of the C1 complex and regulatory proteins, e.g. the C-reactive protein, overview
-
additional information
additional information
-
kinetics of activation of C1s and MASP-3 mutants, overview
-
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
18.3
N-acetyl-Arg methyl ester
Homo sapiens
-
-
12.5
N-Acetyl-Gly-Lys methyl ester
Homo sapiens
-
-
0.0645
zymogen C1s
Homo sapiens
-
pH 7.4, 37C, substrate is a fragment consisting of complement control protein domains, CCP1 and CCP2, plus serine
-
0.0021
MASP-3 K448Q zymogen
Homo sapiens
-
pH 7.4, 37C
-
additional information
additional information
Homo sapiens
-
activated C1r and its wild-type CCP1/2-SP and CCP2-SP fragments all cleave acetyl-Gly-Lys-methyl ester with turnover numbers ranging from 8.2 s to 9.2 s
-
kcat/KM VALUE [1/mMs-1]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
340
MASP-3 K448Q zymogen
Homo sapiens
-
pH 7.4, 37C
202404
2900
zymogen C1s
Homo sapiens
-
pH 7.4, 37C, substrate is a fragment consisting of complement control protein domains, CCP1 and CCP2, plus serine
202403
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
7.4
-
assay at
7.5 - 8.5
-
-
8
-
assay at
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
37
-
assay at
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE
-
nasopharyngeal carcinoma cells
Manually annotated by BRENDA team
-
MEF-2 cell, low-density lipoprotein receptor-related protein 1-deficient macrophages show increased expression of C1r
Manually annotated by BRENDA team
-
C1r mRNA expression is significantly increased in RAW 264.7 cells in which low-density lipoprotein receptorrelated protein 1 is silenced
Manually annotated by BRENDA team
additional information
-
PEA-10 cell and B-41 cell
Manually annotated by BRENDA team
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
-
as C1 complex, i.e. C1s-C1r-C1r-C1s tetramer
-
Manually annotated by BRENDA team
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
16600
-
gel filtration
81393
90000
-
immunoblot analysis, in PEA-10 and B-41 cells, single-chain form, which is the zymogen
696932
790000
-
-
717805
additional information
-
molecular weight of C1r fragments
652176
additional information
-
molecular weight of the CCP1-CCP2-SP fragments
652680
additional information
-
MW of C1r: 166000-188000 Da, gel filtration
81403
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
?
-
x * 88000, C1r zymogen, domain structure, overview
dimer
-
CCP1 is essential to the assembly of the dimer, but formation of a stable dimer is not a prerequisite for self-activation
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
dimer
-
2 * 83000, SDS-PAGE of reduced protein, gel filtration in 6 M guanidinium hydrochloride
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
heteropentamer
-
C1q, 2 * C1s, 2 * C1r
additional information
-
C1 complex structure
additional information
-
C1r and C1s pro-enzymes form a heterotetrameric structure that associates with the recognition molecule, C1q, in the C1 complex
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
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
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
additional information
-
C1rbar and the proenzyme C1r are noncovalent dimers, the subunit of C1r has a MW of 53000-85000 Da, SDS-PAGE
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
glycoprotein
-
carbohydrate content of C1r fragments
glycoprotein
-
-
proteolytic modification
-
autoactivation of C1r as part of the C1 complex
proteolytic modification
-
autoactivation of C1r as part of the C1 complex, modeling, overview
proteolytic modification
-
activation of C1r involves cleavage of a single peptide bond which converts the proenzyme into active enzyme. Activation of the serine-proteinase domain of C1r is controlled by a Ca2+-dependent intramolecular mechanism involving the Ca2+-binding alpha-region. This control is released in C1 by a signal originating in C1q and transmitted through the C1q/C1r interface
proteolytic modification
-
-
proteolytic modification
-
binding of C1 to activator is mediated by C1q and triggers activation of proenzyme C1r into an active protease C1rbar
proteolytic modification
-
activation of the proenzyme C1r can be mimicked under certain conditions by digestion of C1r with trypsin or plasmin; the proenzyme is C1r
proteolytic modification
-
the proenzyme C1r is not autoactivatable but undergoes proteolysis by exogenous C1rbar
proteolytic modification
-
autolytic proteolysis involves cleavage of the Arg279-Gly280 bond in the sequence Asp-Ser-Arg-Gly-Trp-Lys
side-chain modification
-
the zymogen C1r is a glycoprotein
side-chain modification
-
the A-chain contains 7.4% carbohydrate and the B-chain contains 12.4% carbohydrate
side-chain modification
-
C1rbar contains about 40 carbohydrate residues per molecule; the zymogen C1r is a glycoprotein
side-chain modification
-
in the case of the recombinant proteins the incompletely processed N-linked carbohydrate chains lack at least the terminal sialic acid residues
side-chain modification
-
postranslational modification of C1r by beta-hydroxylation of specific Asp and Asn residues, 10% of the recombinant C1r is hydroxylated
Crystallization/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
crystal structure analysis, PDB IDs 1APQ
-
hanging drop vapour diffusion method, crystal structure of two fragments from the human C1r catalytic domain, each encompassing the second complement control protein CCP2 module and the SP domain. The wild-type species has an active structure, whereas the S637A mutant is a zymogen
-
hanging drop vapour diffusion, crystal structure of a mutated proenzyme form of the catalytic domain of human C1r, and the serine protease domain solved and refined to 2.9 A resolution
-
purified recombinant isolated active catalytic region forming a dimer in a head-to-tail fashion, complex of enzyme and product, hanging drop vapour diffusion method, 15C, mixing of 0.008 ml protein solution, containing 0.2 mg/ml protein, 20 mM Tris-HCl, pH 7.4, and 130 mM NaC, with 0.008 ml reservoir solution containing 14% w/v PEG 6000, 0.2 M NaCl, 10% v/v glycerol, and 0.1 M Tris-HCl, pH 7.4, cryoprotection of crystals in 20% glycerol, X-ray diffraction structure determination and analysis at 2.6 A resolution, molecular replacement
-
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
additional information
-
melting transition of SP fragment is 47.5C, melting point of the CCP2-SP fragment is 55.4C, the CCP1-CCP2-SP fragment shows an unfolding transition at 57.5C
652680
additional information
-
high temperature transition occurs at 53C, the low-temperature transition varies between 26C at low ionic strength and 40C in the presence of 0.5 M NaCl
81386, 81403
GENERAL STABILITY
ORGANISM
UNIPROT
LITERATURE
after reduction and alkylation C1rbar undergoes proteolytic cleavage which lead to the successive removal of two fragments of 35000 Da and of 7000-10000 Da, leaving a divalent molecule of reduced size. The product C1rbar II retains the original antigenic properties of C1rbar and a functional active site, but loses the capacity to bind C1s
-
C1rbar undergoes autolytic cleavage
-
STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
2C, pH 5.3-7.3, in absence of Ca2+, 2 weeks, stable
-
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
commercial preparation
-
from human plasma
-
from inclusion bodies, ion exchange chromatography (Q-Sepharose), gel filtration
-
proenzyme C1r
-
recombinant active catalytic region of C1r from Escherichia coli strain BL21(DE3) by ion exchange chromatography and gel filtration
-
solubilization of inclusion-bodies
-
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
baculovirus-mediated expression is used to produce fragments containing the SP domain and either 2 CCP modules (CCP1/2-SP) or only the second CCP module (CCP2-SP). In each case the wild-type species and two mutants stabilized in the proenzyme form by mutations at the cleavage site (R446Q) or at the active site serine residue (S637A) are produced
-
CUB2-complement control protein 1 module expressed in Escherichia coli BL21(DE3) pLysS
-
development and evaluation of a method for expression of recombinant full-length human C-terminally tagged C1q involving stable transfection of HEK 293-F mammalian cells
-
expression in insect cells
-
expression in insect Sf9,High5 cells
-
expression of complement control protein module 2 (I356-V433), complement control protein module 1 - complement control protein module 2 (I289-V433), CUB2 - complement control protein module 1 (Q173-D358) and CUB2 - complement control protein module 1 - complement control protein module 2 (Q173-V433)
-
expression of modules: Q173-D358 (CUB2-complement control protein 1) and I356-V433 (complement control protein 2)
-
expression of the isolated active catalytic region, containing the C-terminal serine protease domain, and two preceding complement control protein modules, of C1r in Escherichia coli strain BL21(DE3)
-
production of the CCP1-CCP2-SP, the CCP2-SP and the SP fragments in Escherichia coli
-
recombinant expression of full-length C1r protease and the CUB1-EGF-CUB2 fragment with low yield
-
Xld is overexpressed in Xenopus embryos
-
ENGINEERING
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
R446Q
-
stabilized in the single-chain proenzyme form by mutation at the cleavage site, no esterolytic activity with acetyl-Gly-Lys-methyl ester
R463X
-
construction of a stable zymogen by mutating the Arg463Ile bond shows that one active C1r in the C1 complex is sufficient for the full activity of the entire complex
R463X
-
the mutations Arg463Gln, Arg463Lys or Arg463Phe all stabilize the zymogen state
R463X
-
the mutants of the proenzyme Arg463Lys,Ile464Phe have increased stability, they retain their ability to autoactivate and have wild-type like hemolytic activity
S637A
-
stabilized in the single-chain proenzyme form by mutation at the active site serine residue, no esterolytic activity with acetyl-Gly-Lys-methyl ester
S654A
-
mutant without autoactivation
additional information
-
by the point mutation of C1r - Arg-Phe - of the natural cleavage site Arg-Ile - the zymogen is stabilized, while the biological activity is not affected
Renatured/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
reconstitution of the C1 complex using purified C1q, C1r and C1s in the presence of C1-INH, interaction with C-reactive protein CRP, overview
-
APPLICATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
medicine
-
anti-inflammatory functions are exerted via inhibition of complement system proteases (C1r, C1s, MASP2) and the plasma kallikrein-kinin system proteases