{"doi":"10.1101/2020.02.20.933945","title":"Directed evolution of <i>Anabaena variabilis</i> phenylalanine ammonia-lyase (PAL) identifies mutants with enhanced activities","abstract":"There is broad interest in engineering phenylalanine ammonia-lyase (PAL) for its biocatalytic applications in industry (fine-chemicals and natural product synthesis) and medicine (phenylketoruria/PKU and cancer treatment). While site-specific mutagenesis has been employed to improve PAL stability or substrate specificity, a more comprehensive mutational landscape has yet to be explored for this class of enzymes. Here, we report development of a directed evolution technique to engineer PAL enzymes. Central to this approach is a high-throughput enrichment that couples E. coli growth to PAL activity. Using the clinically-relevant PAL from Anabaena variabilis , which is used on the formulation of pegvaliase for PKU therapy, we identified mutations at residues previously unknown as relevant for function that increase turnover frequency almost twofold after only a single round of engineering. This work demonstrates the power our technique for ammonia-lyase enzyme engineering.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2020,"id":126280,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9494,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":574250,"name":"Karishma Mohan","orcid":null,"position":1,"is_corresponding":false},{"id":573701,"name":"Vikas D. Trivedi","orcid":"0000-0002-2703-8311","position":2,"is_corresponding":false},{"id":332940,"name":"Todd C. Chappell","orcid":null,"position":3,"is_corresponding":false},{"id":331408,"name":"Nikhil U. Nair","orcid":"0000-0001-7737-1385","position":4,"is_corresponding":false},{"id":354578,"name":"Zachary J. S. Mays","orcid":null,"position":0,"is_corresponding":true}],"reference_count":44,"raw_metadata":null,"created_at":"2026-07-18T23:15:23.509897Z","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":[]}