{"doi":"10.1159/000458907","title":"Congenital Methylmalonic Acidemia: a Variant of the B\n‘Non-Responsive’ Form with Evidence for Reduced Affinity of\nMethylmalonyl-CoA Mutase for its B(12)-Coenzyme","abstract":"<jats:p>Methylmalonate metabolism was investigated in fibroblasts and leukocytes\nof two unrelated patients with a B(12)-nonresponsive type of congenital methylmalonic\nacidemia. Intact fibroblasts from both patients showed a defective metabolism of methyl^-14\nC-malonate to 14C0(2), whereas no such defect was found in their intact peripheral leukocytes.\nIn disrupted fibroblasts, the conversion of methylmalonyl coenzyme A to succinyl\ncoenzyme A was markedly reduced but was completely normalized by the addition of\n5'-deoxyadenosylcobalamin (AdoCbl; 10^-5 mol/l), the specific coenzyme of methylmalonyl\ncoenzyme A mutase. Assays with decreasing concentrations of AdoCbl (10^-5-10^-11 mol/l)\nsuggested a reduced affinity of the mutase apoenzyme for its coenzyme, implicating yet\nanother variant of this heterogeneous disease.</jats:p>","journal":"Enzyme","year":2017,"id":681569,"datarank":0.24141568686511508,"base_score":1.6094379124341003,"endowment":1.6094379124341003,"self_citation_contribution":0.24141568686511508,"citation_network_contribution":0.0,"self_endowment_contribution":0.24141568686511508,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":4,"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":1780765,"name":"E. Regula Baumgartner","orcid":null,"position":1,"is_corresponding":false},{"id":1780766,"name":"Claude Bachmann","orcid":null,"position":2,"is_corresponding":false},{"id":1780764,"name":"Hugo Wick","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Congenital Methylmalonic Acidemia: a Variant of the B\n‘Non-Responsive’ Form with Evidence for Reduced Affinity of\nMethylmalonyl-CoA Mutase for its B(12)-Coenzyme","abstract":"<jats:p>Methylmalonate metabolism was investigated in fibroblasts and leukocytes\nof two unrelated patients with a B(12)-nonresponsive type of congenital methylmalonic\nacidemia. Intact fibroblasts from both patients showed a defective metabolism of methyl^-14\nC-malonate to 14C0(2), whereas no such defect was found in their intact peripheral leukocytes.\nIn disrupted fibroblasts, the conversion of methylmalonyl coenzyme A to succinyl\ncoenzyme A was markedly reduced but was completely normalized by the addition of\n5'-deoxyadenosylcobalamin (AdoCbl; 10^-5 mol/l), the specific coenzyme of methylmalonyl\ncoenzyme A mutase. Assays with decreasing concentrations of AdoCbl (10^-5-10^-11 mol/l)\nsuggested a reduced affinity of the mutase apoenzyme for its coenzyme, implicating yet\nanother variant of this heterogeneous disease.</jats:p>","is_dataset_classified":null,"base_score":1.6094379124341003,"endowment":1.6094379124341003,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"12939","pmcid":null,"openalex_id":"https://openalex.org/W2410398343","authors":[],"funders":[],"total_grants":0,"fwci":0.0,"citation_percentile":0.00609397,"influential_citations":0,"citation_trend":[{"year":2016,"count":1}],"oa_status":"closed","license":"https://karger.com/pages/terms-and-conditions","oa_locations":[{"url":"https://karger.com/article-pdf/doi/10.1159/000458907","host_type":"publisher"},{"url":"https://doi.org/10.1159/000458907","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/12939","host_type":"repository"}],"fields_of_study":["Metabolism and Genetic Disorders","Folate and B Vitamins Research","Biochemical and Molecular Research","Amino Acid Metabolism, Inborn Errors","Female","Fibroblasts","Genetic Variation","Humans","Infant, Newborn","Isomerases","Kinetics","Leukocytes","Malonates","Methylmalonic Acid","Methylmalonyl-CoA Mutase","Vitamin B 12"],"mesh_terms":["Amino Acid Metabolism, Inborn Errors","Female","Fibroblasts","Humans","Infant, Newborn","Isomerases","Kinetics","Leukocytes","Malonates","Methylmalonic Acid","Methylmalonyl-CoA Mutase","Genetic Variation","Vitamin B 12"],"keywords":["Mutase","Methylmalonic acidemia","Cofactor","Adenosylcobalamin","Biochemistry","Methylcobalamin","Coenzyme A","Chemistry","Metabolism","Enzyme","Biology","Molecular biology","Vitamin B12","Endocrinology","Reductase"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-17T18:08:10.461584Z","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":[]}