Douglas J. Fansher, Jonathan N. Besna and Joelle N. Pelletier
{"title":"靛蓝生产确定了细胞色素 P450 BM3 中芳香烃羟化多样化的热点。","authors":"Douglas J. Fansher, Jonathan N. Besna and Joelle N. Pelletier","doi":"10.1039/D4FD00017J","DOIUrl":null,"url":null,"abstract":"<p >Evolution of P450 BM3 is a topic of extensive research, but screening the various substrate/reaction combinations remains a time-consuming process. Indigo production has the potential to serve as a simple high-throughput method for reaction screening, as bacterial colonies expressing indigo (+) variants can be visually identified <em>via</em> their blue phenotype. Indigo (+) single variants, indigo (−) single variants and a combinatorial library, containing mutations that enable the blue phenotype, were screened for their ability to hydroxylate a panel of 12 aromatic compounds using the 4-aminoantipyrine colorimetric assay. Recombination of indigo (+) single variants to create a multiple-variant library is a particularly useful strategy, as all top performing P450 BM3 variants with high hydroxylation activity were either indigo (+) single variants or contained multiple substitutions. Furthermore, active variants, as determined using the 4-AAP assay, were further characterized and several variants were identified that gave more than 90% conversion with 1,3-dichlorobenzene and predominantly formed 2,6-dichlorophenol; other variants showed significant substrate selectivity. This supports the hypothesis that substitution at positions that enable the indigo (+) phenotype, or hotspot residues, is a general mechanism for increasing aromatic hydroxylation activity. Overall, this research demonstrates that indigo (+) single variants, identified <em>via</em> colorimetric colony-based screening, may be recombined to generate a multiply-substituted variant library containing many variants with high aromatic hydroxylation activity. The combination of colony-based screening and other screening assays greatly accelerates enzyme engineering, as readily-identified indigo (+) single variants can be recombined to create a library of active multiple variants without extensive screening of single variants.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"252 ","pages":" 29-51"},"PeriodicalIF":3.4000,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Indigo production identifies hotspots in cytochrome P450 BM3 for diversifying aromatic hydroxylation†\",\"authors\":\"Douglas J. Fansher, Jonathan N. Besna and Joelle N. Pelletier\",\"doi\":\"10.1039/D4FD00017J\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >Evolution of P450 BM3 is a topic of extensive research, but screening the various substrate/reaction combinations remains a time-consuming process. Indigo production has the potential to serve as a simple high-throughput method for reaction screening, as bacterial colonies expressing indigo (+) variants can be visually identified <em>via</em> their blue phenotype. Indigo (+) single variants, indigo (−) single variants and a combinatorial library, containing mutations that enable the blue phenotype, were screened for their ability to hydroxylate a panel of 12 aromatic compounds using the 4-aminoantipyrine colorimetric assay. Recombination of indigo (+) single variants to create a multiple-variant library is a particularly useful strategy, as all top performing P450 BM3 variants with high hydroxylation activity were either indigo (+) single variants or contained multiple substitutions. Furthermore, active variants, as determined using the 4-AAP assay, were further characterized and several variants were identified that gave more than 90% conversion with 1,3-dichlorobenzene and predominantly formed 2,6-dichlorophenol; other variants showed significant substrate selectivity. This supports the hypothesis that substitution at positions that enable the indigo (+) phenotype, or hotspot residues, is a general mechanism for increasing aromatic hydroxylation activity. Overall, this research demonstrates that indigo (+) single variants, identified <em>via</em> colorimetric colony-based screening, may be recombined to generate a multiply-substituted variant library containing many variants with high aromatic hydroxylation activity. The combination of colony-based screening and other screening assays greatly accelerates enzyme engineering, as readily-identified indigo (+) single variants can be recombined to create a library of active multiple variants without extensive screening of single variants.</p>\",\"PeriodicalId\":49075,\"journal\":{\"name\":\"Faraday Discussions\",\"volume\":\"252 \",\"pages\":\" 29-51\"},\"PeriodicalIF\":3.4000,\"publicationDate\":\"2024-07-12\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Faraday Discussions\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://pubs.rsc.org/en/content/articlelanding/2024/fd/d4fd00017j\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"Chemistry\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Faraday Discussions","FirstCategoryId":"92","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2024/fd/d4fd00017j","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"Chemistry","Score":null,"Total":0}
Indigo production identifies hotspots in cytochrome P450 BM3 for diversifying aromatic hydroxylation†
Evolution of P450 BM3 is a topic of extensive research, but screening the various substrate/reaction combinations remains a time-consuming process. Indigo production has the potential to serve as a simple high-throughput method for reaction screening, as bacterial colonies expressing indigo (+) variants can be visually identified via their blue phenotype. Indigo (+) single variants, indigo (−) single variants and a combinatorial library, containing mutations that enable the blue phenotype, were screened for their ability to hydroxylate a panel of 12 aromatic compounds using the 4-aminoantipyrine colorimetric assay. Recombination of indigo (+) single variants to create a multiple-variant library is a particularly useful strategy, as all top performing P450 BM3 variants with high hydroxylation activity were either indigo (+) single variants or contained multiple substitutions. Furthermore, active variants, as determined using the 4-AAP assay, were further characterized and several variants were identified that gave more than 90% conversion with 1,3-dichlorobenzene and predominantly formed 2,6-dichlorophenol; other variants showed significant substrate selectivity. This supports the hypothesis that substitution at positions that enable the indigo (+) phenotype, or hotspot residues, is a general mechanism for increasing aromatic hydroxylation activity. Overall, this research demonstrates that indigo (+) single variants, identified via colorimetric colony-based screening, may be recombined to generate a multiply-substituted variant library containing many variants with high aromatic hydroxylation activity. The combination of colony-based screening and other screening assays greatly accelerates enzyme engineering, as readily-identified indigo (+) single variants can be recombined to create a library of active multiple variants without extensive screening of single variants.