{"doi":"10.1515/bchm3.1993.374.1-6.85","title":"On the Role of two Different Cobalt(II) Species in Coenzyme B<sub><b>12</b></sub>-Dependent 2-Methyleneglutarate Mutase from<i>Clostridium barkeri</i>","abstract":null,"journal":"Biological Chemistry Hoppe-Seyler","year":1993,"id":652603,"datarank":0.4566783656585135,"base_score":3.044522437723423,"endowment":3.044522437723423,"self_citation_contribution":0.4566783656585135,"citation_network_contribution":0.0,"self_endowment_contribution":0.4566783656585135,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":20,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"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":1702441,"name":"Wolfgang BUCKEL","orcid":null,"position":1,"is_corresponding":false},{"id":1702440,"name":"Oskar ZELDER","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"On the Role of two Different Cobalt(II) Species in Coenzyme B<sub><b>12</b></sub>-Dependent 2-Methyleneglutarate Mutase from<i>Clostridium barkeri</i>","abstract":"Purified 2-methyleneglutarate mutase from Clostridium barkeri contains adenosylcobalamin (coenzyme B12) and varying amounts of oxygen-stable cob(II)alamin. The content of the latter was estimated by EPR spectroscopy at 6-11% of the total cobalamin (2-4 mol/mol enzyme). Tryptic digestion of the enzyme liberated the prosthetic groups, cob(II)alamin being oxidized by air to aquocobalamin. HPLC analysis of the released cobamides from several preparations revealed > 90% adenosylcobalamin and < 10% aquocobalamin. Treatment of active 2-methyleneglutarate mutase with 8M urea followed by gelfiltration yielded an inactive enzyme from which 50% of the adenosylcobalamin and up to 70% of the cob(II)alamin was removed. Addition of adenosylcobalamin to the urea-treated enzyme resulted in complete reactivation, but the content of cob(II)alamin was not increased. These data suggest that the oxygen-stable cob(II)alamin is not involved in catalysis. In the presence of the competitive inhibitor itaconate (methylenesuccinate, Ki = 0.7mM), an alteration of the UV/visible spectrum at 470 nm as well as a new line in the EPR spectrum of the enzyme (around g = 2.1) was observed. The results indicate the formation of an unusual, oxygen sensitive Co(II) species during catalysis. The EPR signal of the oxygen-stable cob(II)alamin (gx,y = 2.24) remained unchanged under those conditions.","is_dataset_classified":null,"base_score":3.044522437723423,"endowment":3.044522437723423,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"8382495","pmcid":null,"openalex_id":"https://openalex.org/W2315625974","authors":[],"funders":[],"total_grants":0,"fwci":1.2157,"citation_percentile":0.79193092,"influential_citations":0,"citation_trend":[{"year":2022,"count":1}],"oa_status":"closed","license":null,"oa_locations":[{"url":"https://www.degruyter.com/document/doi/10.1515/bchm3.1993.374.1-6.85/pdf","host_type":"publisher"},{"url":"https://doi.org/10.1515/bchm3.1993.374.1-6.85","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/8382495","host_type":"repository"}],"fields_of_study":["Porphyrin Metabolism and Disorders","Folate and B Vitamins Research","Biochemical and Molecular Research"],"mesh_terms":["Catalysis","Chromatography, High Pressure Liquid","Clostridium","Cobalt","Cobamides","Electron Spin Resonance Spectroscopy","Isomerases","Spectrophotometry, Ultraviolet","Intramolecular Transferases"],"keywords":["Adenosylcobalamin","Mutase","Chemistry","Cofactor","Enzyme","Methylcobalamin","Catalysis","Oxygen","Electron paramagnetic resonance","Methanosarcina barkeri","Biochemistry","Organic chemistry","Nuclear magnetic resonance","Methanogenesis"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-10T16:10:05.378345Z","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":[]}