IntAct European Bioinformatics Institute IntAct intact http://www.ebi.ac.uk/ http://www.ebi.ac.uk/intact/query/${ac} EBI-[0-9]+|IA:[0-9]+ INTerAction database (IntAct) provides an open source database and toolkit for the storage, presentation and analysis of molecular interactions. http://www.ebi.ac.uk/intact European Bioinformatics Institute; Wellcome Trust Genome Campus; Hinxton, Cambridge; CB10 1SD; United Kingdom http://www.ebi.ac.uk/intact/ Mock publication and experiment for abstract interactions that are not interaction evidences. Mock publication and experiment for abstract interactions that are not interaction evidences. unspecified method Serglycin inhibits the classical and lectin pathways of complement via its glycosaminoglycan chains: implications for multiple myeloma. Serglycin inhibits the classical and lectin pathways of complement via its glycosaminoglycan chains: implications for multiple myeloma. European journal of immunology 2011 imex curation Skliris A., Happonen KE., Terpos E., Labropoulou V., Børset M., Heinegård D., Blom AM., Theocharis AD. re GAGs: I could not find the "NIH mucopolysaccharide standard collection" at all, nor anything useful on the Seikagaku web site. Serglycin was purified from conditioned medium of four Multiple Myeloma cell lines. anna.blom@med.lu.se 29-Mar-2021: Contacted by IntAct-Help. Only protein-protein interactions imex curation in vitro In vitro elisa enzyme linked immunosorbent assay ELISA ELISA elisa antibody detection identification by antibody antibody detection Skliris A., Happonen KE., Terpos E., Labropoulou V., Børset M., Heinegård D., Blom AM., Theocharis AD. re GAGs: I could not find the "NIH mucopolysaccharide standard collection" at all, nor anything useful on the Seikagaku web site. Serglycin was purified from conditioned medium of four Multiple Myeloma cell lines. Purified MBL has been assumed to be of Human origin, as most instances in the text refer to MBL in relation to human serum. anna.blom@med.lu.se Accepted 2021-FEB-18 AT 13:59 GMT AT 13:59 GMT by LUANA European journal of immunology 2011 Only protein-protein interactions imex curation imex curation Serglycin was purified from conditioned medium of four Multiple Myeloma cell lines. Serglycin inhibits the classical and lectin pathways of complement via its glycosaminoglycan chains: implications for multiple myeloma. Serglycin inhibits the classical and lectin pathways of complement via its glycosaminoglycan chains: implications for multiple myeloma. European journal of immunology 2011 imex curation Skliris A., Happonen KE., Terpos E., Labropoulou V., Børset M., Heinegård D., Blom AM., Theocharis AD. re GAGs: I could not find the "NIH mucopolysaccharide standard collection" at all, nor anything useful on the Seikagaku web site. Serglycin was purified from conditioned medium of four Multiple Myeloma cell lines. anna.blom@med.lu.se 29-Mar-2021: Contacted by IntAct-Help. Only protein-protein interactions imex curation in vitro In vitro solid phase assay solid phase assay tag visualisation tag visualisation Skliris A., Happonen KE., Terpos E., Labropoulou V., Børset M., Heinegård D., Blom AM., Theocharis AD. re GAGs: I could not find the "NIH mucopolysaccharide standard collection" at all, nor anything useful on the Seikagaku web site. Serglycin was purified from conditioned medium of four Multiple Myeloma cell lines. anna.blom@med.lu.se Accepted 2021-FEB-18 AT 13:59 GMT AT 13:59 GMT by LUANA European journal of immunology 2011 Only protein-protein interactions imex curation imex curation chondroitin 6'-sulfate chondroitin 6'-sulfate chondroitin 6'-sulfate Chondroitin 6'-sulfate chondroitin 6-(hydrogen sulfate) Chondroitin 6-sulfate Chondroitin sulfate C small molecule small molecule chemical synthesis Chemical synthesis (Chemical synthesis) c1qb_human Complement C1q subcomponent subunit B C1QB protein protein human Homo sapiens Human MMMKIPWGSIPVLMLLLLLGLIDISQAQLSCTGPPAIPGIPGIPGTPGPDGQPGTPGIKGEKGLPGLAGDHGEFGEKGDPGIPGNPGKVGPKGPMGPKGGPGAPGAPGPKGESGDYKATQKIAFSATRTINVPLRRDQTIRFDHVITNMNNNYEPRSGKFTCKVPGLYYFTYHASSRGNLCVNLMRGRERAQKVVTFCDYAYNTFQVTTGGMVLKLEQGENVFLQATDKNSLLGMEGANSIFSGFLLFPDMEA D80C753C0D430EDC c1qa_human Complement C1q subcomponent subunit A C1QA protein protein human Homo sapiens Human MEGPRGWLVLCVLAISLASMVTEDLCRAPDGKKGEAGRPGRRGRPGLKGEQGEPGAPGIRTGIQGLKGDQGEPGPSGNPGKVGYPGPSGPLGARGIPGIKGTKGSPGNIKDQPRPAFSAIRRNPPMGGNVVIFDTVITNQEEPYQNHSGRFVCTVPGYYYFTFQVLSQWEICLSIVSSSRGQVRRSLGFCDTTNKGLFQVVSGGMVLQLQQGDQVWVEKDPKKGHIYQGSEADSVFSGFLIFPSA DIP protein P02745 original sequence version: null 8FF6B6AE02D49C4C fmod_bovin Fibromodulin FMOD Collagen-binding 59 kDa protein Keratan sulfate proteoglycan fibromodulin protein protein bovin Bos taurus (Bovine) Bovine MQWASILLLAGLCSLSWAQYEEDSHWWFQFLRNQQSTYDDPYDPYPYEPYEPYPYGGEEGPAYAYGSPPQPEPRDCPQECDCPPNFPTAMYCDNRNLKYLPFVPSRMKYVYFQNNQISSIQEGVFDNATGLLWIALHGNQITSDKVGKKVFSKLRHLERLYLDHNNLTRIPSPLPRSLRELHLDHNQISRVPNNALEGLENLTALYLHHNEIQEVGSSMKGLRSLILLDLSYNHLRKVPDGLPSALEQLYLEHNNVFSVPDSYFRGSPKLLYVRLSHNSLTNNGLASNTFNSSSLLELDLSYNQLQKIPPVSTNLENLYLQGNRINEFSISSFCTVVDVMNFSKLQVLRLDGNEIKRSAMPADAPLCLRLASLIEI CC4AA5B0AC79907B heparin Heparin small molecule small molecule chemical synthesis Chemical synthesis (Chemical synthesis) chondroitin sulfate-1 chondroitin sulfate chondroitin polysulfate Chondroitin sulfate chondroitin sulfates chondroitin sulfuric acid chondroitin sulphate Chondroitinsulfat small molecule small molecule chemical synthesis Chemical synthesis (Chemical synthesis) keratan sulfate keratan sulfate keratan sulfates keratosulfate small molecule small molecule chemical synthesis Chemical synthesis (Chemical synthesis) chondroitin sulfate e chondroitin sulfate E small molecule small molecule chemical synthesis Chemical synthesis (Chemical synthesis) pgs2_bovin Decorin Bone proteoglycan II PG-S2 DCN protein protein bovin Bos taurus (Bovine) Bovine MKATIIFLLVAQVSWAGPFQQKGLFDFMLEDEASGIGPEEHFPEVPEIEPMGPVCPFRCQCHLRVVQCSDLGLEKVPKDLPPDTALLDLQNNKITEIKDGDFKNLKNLHTLILINNKISKISPGAFAPLVKLERLYLSKNQLKELPEKMPKTLQELRVHENEITKVRKSVFNGLNQMIVVELGTNPLKSSGIENGAFQGMKKLSYIRIADTNITTIPQGLPPSLTELHLDGNKITKVDAASLKGLNNLAKLGLSFNSISAVDNGSLANTPHLRELHLNNNKLVKVPGGLADHKYIQVVYLHNNNISAIGSNDFCPPGYNTKKASYSGVSLFSNPVQYWEIQPSTFRCVYVRAAVQLGNYK F7B5B61C2A67CB5E mbl2_human Mannose-binding protein C MBL2 COLEC1 MBL Collectin-1 MBP1 Mannan-binding protein Mannose-binding lectin protein protein human Homo sapiens Human MSLFPSLPLLLLSMVAASYSETVTCEDAQKTCPAVIACSSPGINGFPGKDGRDGTKGEKGEPGQGLRGLQGPPGKLGPPGNPGPSGSPGPKGQKGDPGKSPDGDSSLAASERKALQTEMARIKKWLTFSLGKQVGNKFFLTNGEIMTFEKVKALCVKFQASVATPRNAAENGAIQNLIKEEAFLGITDEKTEGQFVDLTGNRLTYTNWNEGEPNNAGSDEDCVLLLKNGQWNDVPCSTSHLAVCEFPI DIP protein P11226 original sequence version: 181 C1F2AAED46D0F774 pgs1_bovin Biglycan Bone/cartilage proteoglycan I Leucine-rich PG I PG-S1 BGN protein protein bovin Bos taurus (Bovine) Bovine MWPLWPLAALLALSQALPFEQKAFWDFTLDDGLPMLNDEEASGAETTSGIPDLDSLPPTYSAMCPFGCHCHLRVVQCSDLGLKAVPKEISPDTTLLDLQNNDISELRKDDFKGLQHLYALVLVNNKISKIHEKAFSPLRKLQKLYISKNHLVEIPPNLPSSLVELRIHDNRIRKVPKGVFSGLRNMNCIEMGGNPLENSGFEPGAFDGLKLNYLRISEAKLTGIPKDLPETLNELHLDHNKIQAIELEDLLRYSKLYRLGLGHNQIRMIENGSLSFLPTLRELHLDNNKLSRVPAGLPDLKLLQVVYLHTNNITKVGVNDFCPVGFGVKRAYYNGISLFNNPVPYWEVQPATFRCVTDRLAIQFGNYKK B86C2149723AD0DA c1qc_human Complement C1q subcomponent subunit C C1QC C1QG protein protein human Homo sapiens Human MDVGPSSLPHLGLKLLLLLLLLPLRGQANTGCYGIPGMPGLPGAPGKDGYDGLPGPKGEPGIPAIPGIRGPKGQKGEPGLPGHPGKNGPMGPPGMPGVPGPMGIPGEPGEEGRYKQKFQSVFTVTRQTHQPPAPNSLIRFNAVLTNPQGDYDTSTGKFTCKVPGLYYFVYHASHTANLCVLLYRSGVKVVTFCGHTSKTNQVNSGGVLLRLQVGEEVWLAVNDYYDMVGIQGSDSVFSGFLLFPD FA17117EB7ABFC12 chondroitin-2,6-sulfate (d) CS-D small molecule small molecule chemical synthesis Chemical synthesis (Chemical synthesis) srgn_human Serglycin Secretory granule proteoglycan core protein Platelet proteoglycan core protein SRGN PRG PRG1 Hematopoietic proteoglycan core protein protein protein human Homo sapiens Human MMQKLLKCSRLVLALALILVLESSVQGYPTRRARYQWVRCNPDSNSANCLEEKGPMFELLPGESNKIPRLRTDLFPKTRIQDLNRIFPLSEDYSGSGFGSGSGSGSGSGSGFLTEMEQDYQLVDESDAFHDNLRSLDRNLPSDSQDLGQHGLEEDFML BD7767F39FFBC477 srgn-c1q_human-1 2 20 unspecified role unspecified role prey prey purified purified human-blood human blood blood BLOOD 17 unspecified role unspecified role bait bait purified purified human-myeloma human-myeloma myeloid_progenitor myeloid progenitor cell ES cell-derived direct interaction direct interaction 4A, 5C, 6 Increasing ionic strength; an above physiological concentration of sodium choloride. Chondroitinase ABC treatment;removal of chondroitin sulfate from Serglycin. Serglycin lacking its chondroitin sulfate (CS) chains still bound C1q from solution but this interaction was clearly diminished. c1q_human-srgn-1 3 20 unspecified role unspecified role bait bait purified purified human-blood human blood blood BLOOD 17 unspecified role unspecified role prey prey purified purified region 125i radiolabel 125i radiolabel I125 125I 125I I125 undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined human-myeloma human-myeloma myeloid_progenitor myeloid progenitor cell ES cell-derived direct interaction direct interaction 4B srgn-mbl2-1 2 13 unspecified role unspecified role prey prey purified purified 17 unspecified role unspecified role bait bait purified purified human-myeloma human-myeloma myeloid_progenitor myeloid progenitor cell ES cell-derived direct interaction direct interaction 4D, 5D, 6 Increasing ionic strength; an above physiological concentration of sodium choloride. EDTA (CHEBI:42191) Chondroitinase ABC treatment;removal of chondroitin sulfate from Serglycin. After removal of the chondroitin sulfate (CS) chains from Serglycin with digestion by chondroitinase ABC, less bound MBL was detected compared with that bound to intact Serglycin. srgn-mbl2-2 2 13 unspecified role unspecified role prey prey purified purified 12 unspecified role unspecified role bait bait purified purified bovin-cartilage Bos taurus cartilage Cartilage direct interaction direct interaction 4D, 5D Increasing ionic strength; an above physiological concentration of sodium choloride. EDTA (CHEBI:42191) srgn-c1q_human-2 2 20 unspecified role unspecified role bait bait purified purified human-blood human blood blood BLOOD 17 unspecified role unspecified role prey prey purified purified human-myeloma human-myeloma myeloid_progenitor myeloid progenitor cell ES cell-derived direct interaction direct interaction 5A Serglycin bound to the stalk regions of C1q. c1q_human-bgn-1 2 20 unspecified role unspecified role bait bait purified purified human-blood human blood blood BLOOD 14 unspecified role unspecified role prey prey purified purified bovin-cartilage Bos taurus cartilage Cartilage direct interaction direct interaction 5A Biglycan bound to the stalk regions of C1q. c1q_human-fmod-1 2 20 unspecified role unspecified role bait bait purified purified human-blood human blood blood BLOOD 7 unspecified role unspecified role prey prey purified purified bovin-cartilage Bos taurus cartilage Cartilage direct interaction direct interaction 5B Fibromodulin bound to the head regions of C1q. srgn-c1q_human-3 2 20 unspecified role unspecified role prey prey purified purified human-blood human blood blood BLOOD 12 unspecified role unspecified role bait bait purified purified bovin-cartilage Bos taurus cartilage Cartilage direct interaction direct interaction 5C Increasing ionic strength; an above physiological concentration of sodium choloride. srgn-c1q_human-4 2 4 inhibitor inhibitor unspecified role unspecified role purified purified 20 unspecified role unspecified role prey prey purified purified human-blood human blood blood BLOOD 17 unspecified role unspecified role bait bait purified purified human-myeloma human-myeloma myeloid_progenitor myeloid progenitor cell ES cell-derived direct interaction direct interaction 6B It is stated that:- "Neither CS-4 nor CS-6 had an effect on the binding between C1q and SG";however two stars are shown on the image for 15ug/ml CS-6, indicating significance at the p<0.01 level. srgn-c1q_human-5 2 16 inhibitor inhibitor unspecified role unspecified role purified purified 20 unspecified role unspecified role prey prey purified purified human-blood human blood blood BLOOD 17 unspecified role unspecified role bait bait purified purified human-myeloma human-myeloma myeloid_progenitor myeloid progenitor cell ES cell-derived direct interaction direct interaction 6B The methods section describes CS-D as having "..sulfate both in the 4 and 6 position of the galactosamine" and CS-E as "sulfate in the 2 position of the glucuronate and 6 position of the galactosamine". However CS-E is elsewhere (including wiki article on gags, chebi database) described as having sulfated "carbons 4 and 6 of the GalNAc sugar" and CS-D as having "carbon 2 of the glucuronic acid and 6 of the GalNAc sugar" (wiki article and pmid:22264297). It would thus appear the methods have the gag's composition listed the "wrong way round". srgn-c1q_human-6 2 11 inhibitor inhibitor unspecified role unspecified role purified purified 20 unspecified role unspecified role prey prey purified purified human-blood human blood blood BLOOD 17 unspecified role unspecified role bait bait purified purified human-myeloma human-myeloma myeloid_progenitor myeloid progenitor cell ES cell-derived direct interaction direct interaction 6B The methods section describes CS-D as having "..sulfate both in the 4 and 6 position of the galactosamine" and CS-E as "sulfate in the 2 position of the glucuronate and 6 position of the galactosamine". However CS-E is elsewhere (including wiki article on gags, chebi database) described as having sulfated "carbons 4 and 6 of the GalNAc sugar" and CS-D as having "carbon 2 of the glucuronic acid and 6 of the GalNAc sugar" (wiki article and pmid:22264297). It would thus appear the methods have the gag's composition listed the "wrong way round". srgn-c1q_human-7 2 8 inhibitor inhibitor unspecified role unspecified role purified purified 20 unspecified role unspecified role prey prey purified purified human-blood human blood blood BLOOD 17 unspecified role unspecified role bait bait purified purified human-myeloma human-myeloma myeloid_progenitor myeloid progenitor cell ES cell-derived direct interaction direct interaction 6B srgn-c1q_human-8 2 9 inhibitor inhibitor unspecified role unspecified role purified purified 20 unspecified role unspecified role prey prey purified purified human-blood human blood blood BLOOD 17 unspecified role unspecified role bait bait purified purified human-myeloma human-myeloma myeloid_progenitor myeloid progenitor cell ES cell-derived direct interaction direct interaction 6B Serglycin-derived Chondroitin Sulfate is stated to be constituted by "4-sulfated disaccharides (92.5%), low amounts of six-sulfated disac- charides (4.5%) and only trace amounts of non-sulfated (1.5%) and (4,6)-disulfated units (1.5%)". srgn-c1q_human-9 2 10 stimulator stimulator unspecified role unspecified role purified purified 20 unspecified role unspecified role prey prey purified purified human-blood human blood blood BLOOD 17 unspecified role unspecified role bait bait purified purified human-myeloma human-myeloma myeloid_progenitor myeloid progenitor cell ES cell-derived direct interaction direct interaction 6B KS‐2 (skeletal KS) was used. [KSII is O-linked to specific serine or threonine amino acids via N-acetylgalactosamine]. srgn-c1q_human-10 2 11 inhibitor inhibitor unspecified role unspecified role purified purified 13 unspecified role unspecified role prey prey purified purified 17 unspecified role unspecified role bait bait purified purified human-myeloma human-myeloma myeloid_progenitor myeloid progenitor cell ES cell-derived direct interaction direct interaction 6D The methods section describes CS-D as having "..sulfate both in the 4 and 6 position of the galactosamine" and CS-E as "sulfate in the 2 position of the glucuronate and 6 position of the galactosamine". However CS-E is elsewhere (including wiki article on gags, chebi database) described as having sulfated "carbons 4 and 6 of the GalNAc sugar" and CS-D as having "carbon 2 of the glucuronic acid and 6 of the GalNAc sugar" (wiki article and pmid:22264297). It would thus appear the methods have the gag's composition listed the "wrong way round". srgn-c1q_human-11 2 8 inhibitor inhibitor unspecified role unspecified role purified purified 13 unspecified role unspecified role prey prey purified purified 17 unspecified role unspecified role bait bait purified purified human-myeloma human-myeloma myeloid_progenitor myeloid progenitor cell ES cell-derived direct interaction direct interaction 6D srgn-c1q_human-12 2 9 inhibitor inhibitor unspecified role unspecified role purified purified 13 unspecified role unspecified role prey prey purified purified 17 unspecified role unspecified role bait bait purified purified human-myeloma human-myeloma myeloid_progenitor myeloid progenitor cell ES cell-derived direct interaction direct interaction 6D Serglycin-derived Chondroitin Sulfate is stated to be constituted by "4-sulfated disaccharides (92.5%), low amounts of six-sulfated disac- charides (4.5%) and only trace amounts of non-sulfated (1.5%) and (4,6)-disulfated units (1.5%)". c1q_human Complement component C1q complex C1q Complement 1q C1QA-C1QB-C1QC complex 6xC1QA:6xC1QB:6xC1QC 5 unspecified role unspecified role cys-31 direct binding direct binding region direct binding certain certain sequence position certain certain certain sequence position certain c1qac binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 15 unspecified role unspecified role c1ab binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain cys-32 binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 6 unspecified role unspecified role cys-26 direct binding direct binding region direct binding certain certain sequence position certain certain certain sequence position certain c1qbc binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 15 unspecified role unspecified role c1ab binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain cys-32 binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 5 unspecified role unspecified role cys-31 direct binding direct binding region direct binding certain certain sequence position certain certain certain sequence position certain c1qac binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 6 unspecified role unspecified role cys-26 direct binding direct binding region direct binding certain certain sequence position certain certain certain sequence position certain c1qbc binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 15 unspecified role unspecified role c1ab binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain cys-32 binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 5 unspecified role unspecified role cys-31 direct binding direct binding region direct binding certain certain sequence position certain certain certain sequence position certain c1qac binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 15 unspecified role unspecified role c1ab binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain cys-32 binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 5 unspecified role unspecified role c1qac binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain cys-31 direct binding direct binding region direct binding certain certain sequence position certain certain certain sequence position certain 6 unspecified role unspecified role cys-26 direct binding direct binding region direct binding certain certain sequence position certain certain certain sequence position certain c1qbc binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 6 unspecified role unspecified role cys-26 direct binding direct binding region direct binding certain certain sequence position certain certain certain sequence position certain c1qbc binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 5 unspecified role unspecified role cys-31 direct binding direct binding region direct binding certain certain sequence position certain certain certain sequence position certain c1qac binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 6 unspecified role unspecified role cys-26 direct binding direct binding region direct binding certain certain sequence position certain certain certain sequence position certain c1qbc binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 15 unspecified role unspecified role c1ab binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain cys-32 binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 15 unspecified role unspecified role c1ab binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain cys-32 binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 6 unspecified role unspecified role cys-26 direct binding direct binding region direct binding certain certain sequence position certain certain certain sequence position certain c1qbc binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 5 unspecified role unspecified role cys-31 direct binding direct binding region direct binding certain certain sequence position certain certain certain sequence position certain c1qac binding region binding region binding-associated region binding region certain certain sequence position certain certain certain sequence position certain 81 87 88 82 84 85 91 106 85 100 91 106 127 94 90 97 100 124 96 93 115 99 103 127 124 102 114 112 105 108 109 111 117 120 123 118 121 126 133 130 129 132 physical association physical association human Homo sapiens Human stable complex stable complex physical interaction evidence used in manual assertion physical interaction evidence used in manual assertion IPI inferred from physical interaction Complement component C1q deficiency (C1QD) [MONDO:0013343]: a disorder caused by impaired activation of the complement classical pathway. It generally leads to severe immune complex disease with features of systemic lupus erythematosus and glomerulonephritis. coronavirus The complex comprises of six heterotrimeric collagen-like triple helices, formed from triplets of the A, B, and C chains, that associate in their N-terminal half to form a stalk, then diverge to form individual stems, each terminating in a C-terminal globular domain. Each of the six heterotrimeric globular heads or domains is made up of the globular domains from one A, one B, and one C chain, each of which in turn has its own ligand specificity. The six collagen-like stalks appear to be fibril-like and exist in the central region. The collagen-like region and the globular heads can independently interact with a multiplicity of biological structures including pathogen-associated and cell associated molecules, also each of the individual globular head domains is capable of independently interacting with specific ligands. Chains A and B are disulfide-linked whilst the C chain forms a disulfide bond with the C chain of the next strand. Molecular weight 460 kDa. Recognition unit of the classical pathway of complement which associates with the Ca2+ - dependent C1r(2)-C1s(2) tetramer to form C1 (CPX-1920), the first component of the classical complement system. The complex's role in C1 is the recognition of immune complexes, or other molecules, which trigger the classical pathway of the complement system. Independent of complement activation C1q appears to have additional roles in homeostasis and cellular development, superoxide (O2-) production by neutrophils, blood coagulation and neurological synapse pruning. Heterooctadecamer created with intact-jami-dbscripts