{"doi":"10.1093/jac/31.2.237","title":"A membrane-bound precursor β-lactamase in strains of <i>Moraxella catarrhalis</i> and <i>Moraxella nonliquefaciens</i> that produce peripiasmic BRO-1 and BRO-2 β-lactamases","abstract":null,"journal":"Journal of Antimicrobial Chemotherapy","year":1993,"id":680617,"datarank":0.41588830833596724,"base_score":2.772588722239781,"endowment":2.772588722239781,"self_citation_contribution":0.41588830833596724,"citation_network_contribution":0.0,"self_endowment_contribution":0.41588830833596724,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":15,"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":108179,"name":"Richard J. Wallace","orcid":"0000-0002-4120-0143","position":1,"is_corresponding":false},{"id":1778277,"name":"Danielle Beaulieu","orcid":null,"position":2,"is_corresponding":false},{"id":1778276,"name":"Vincent A. Steingrube","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"A membrane-bound precursor β-lactamase in strains of <i>Moraxella catarrhalis</i> and <i>Moraxella nonliquefaciens</i> that produce peripiasmic BRO-1 and BRO-2 β-lactamases","abstract":"By employing the non-ionic detergent Triton X-100, a membrane-bound beta-lactamase was extracted from strains of Moraxella (Branhamella) catarrhalis and Moraxella nonliquefaciens that produce BRO-1 and BRO-2 beta-lactamases. Unlike BRO-1 and BRO-2, which exhibit multiple major bands on isoelectric focusing (IEF), the membrane-bound enzyme focused as a single IEF band at a pI of 6.20, which was not present with either of the other two enzymes. The membrane-bound beta-lactamase could be extracted from all strains producing BRO-1 and BRO-2, including recombinant strains constructed by transformation or conjugation. The enzyme was also recovered from Escherichia coli strain HB101 carrying vector plasmid pLQ521 into which the BRO-1 beta-lactamase gene from M. catarrhalis had been cloned. All three beta-lactamases were indistinguishable by inhibitor profiles with clavulanic acid, BRL 42715, sulbactam and tazobactam. These data suggested that all three beta-lactamases were the product of a single gene in Moraxella spp., and that the membrane-bound beta-lactamase serves as a precursor of both BRO-1 and BRO-2. Species differences in cellular processing of the membrane-bound enzyme could explain the minor differences in IEF patterns that occurred with BRO-1 and BRO-2 beta-lactamases when present in different species.","is_dataset_classified":null,"base_score":0.0,"endowment":0.0,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"8463169","pmcid":null,"openalex_id":null,"authors":[],"funders":[],"total_grants":0,"fwci":null,"citation_percentile":null,"influential_citations":0,"citation_trend":[],"oa_status":"closed","license":null,"oa_locations":[{"url":"https://academic.oup.com/jac/article/31/2/237/827886/A-membranebound-precursor-βlactamase-in-strains-of","host_type":"publisher"}],"fields_of_study":[],"mesh_terms":["Cell Membrane","Moraxella","Escherichia coli","Polyethylene Glycols","Octoxynol","Enzyme Precursors","beta-Lactamases","Isoelectric Focusing","Species Specificity","beta-Lactamase Inhibitors","Moraxella catarrhalis"],"keywords":[],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-17T15:35:54.031882Z","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":[]}