{"doi":"10.1042/bst0310748","title":"Biochemistry and genetics of mannan-binding lectin (MBL)","abstract":"<jats:p>Mannose- or mannan-binding lectin (MBL) is a member of the collectin protein family, which includes lung surfactant proteins SP-A and SP-D. Each member consists of similar or identical polypeptide chains with a region of collagen-like sequence followed by a C-type lectin domain. The polypeptides associate in threes to form a subunit containing a collagen-like helix, with three clustered lectin domains. These subunits associate into larger structures, usually with 12–18 polypeptides. The collectins bind to patterns of neutral sugars on surfaces (e.g. of micro-organisms) and mediate effector functions associated with killing/phagocytosis. MBL is the only collectin which activates complement. It resembles in quaternary structure the complement protein C1q, which recognizes targets via charge clusters. Binding of MBL to a surface activates MBL-associated serine proteases (MASPs) attached to MBL, and MASP-2 activates complement proteins C4 and C2. The MASPs are homologous to the C1q-associated proteases, C1r and C1s. MBL therefore activates complement by a mechanism very similar to C1q, and engages the opsonic activity of complement to clear micro-organisms. The serum concentration of MBL is very variable in humans. The variability is largely associated with mutations leading to amino acid substitutions in the collagen-like region which decrease MBL assembly and stability. Many studies demonstrate that MBL deficiency is associated with susceptibility to a range of infectious and inflammatory diseases.</jats:p>","journal":"Biochemical Society Transactions","year":2003,"id":31901,"datarank":3.542639056203227,"base_score":4.0943445622221,"endowment":4.0943445622221,"self_citation_contribution":0.6141516843333151,"citation_network_contribution":2.928487371869912,"self_endowment_contribution":0.6141516843333151,"citer_contribution":2.928487371869912,"corpus_percentile":null,"corpus_rank":null,"citation_count":59,"citer_count":56,"citers_with_citation_signal":46,"citers_with_endowment":46,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":169982,"name":"M. Kojima","orcid":null,"position":1,"is_corresponding":false},{"id":169985,"name":"R.B. Sim","orcid":null,"position":2,"is_corresponding":false},{"id":169979,"name":"J.S. Presanis","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"base_score":4.0943445622221,"endowment":4.0943445622221,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"12887296","pmcid":null,"openalex_id":"https://openalex.org/W1963747204","authors":[],"funders":[],"total_grants":0,"fwci":1.6621,"citation_percentile":0.83086124,"influential_citations":4,"citation_trend":[{"year":2012,"count":5},{"year":2014,"count":3},{"year":2015,"count":1},{"year":2016,"count":2},{"year":2018,"count":4},{"year":2019,"count":2},{"year":2021,"count":1},{"year":2022,"count":4},{"year":2023,"count":1},{"year":2025,"count":2}],"oa_status":"closed","license":null,"oa_locations":[{"url":"https://portlandpress.com/biochemsoctrans/article-pdf/31/4/748/531422/bst0310748.pdf","host_type":"publisher"},{"url":"https://doi.org/10.1042/bst0310748","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/12887296","host_type":"repository"}],"fields_of_study":["Complement system in diseases","Platelet Disorders and Treatments","Hemoglobinopathies and Related Disorders","Biology","Medicine","Chemistry","Complement Pathway, Mannose-Binding Lectin","Humans","Mannose-Binding Lectin","Protein Subunits","Serine Endopeptidases"],"mesh_terms":["Humans","Serine Endopeptidases","Protein Subunits","Complement Pathway, Mannose-Binding Lectin","Mannose-Binding Lectin"],"keywords":["Collectin","Mannan-binding lectin","Lectin pathway","Complement system","Lectin","Ficolin","Proteases","Biology","MASP1","C-type lectin","Biochemistry","Protein subunit","Classical complement pathway","Alternative complement pathway","Innate immune system","Cell biology","Immune system","Genetics","Serine protease","Receptor","Enzyme","Gene"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-06-09T09:09:48.115893Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}