title: Hemin-utilizing G-quadruplex DNAzymes are strongly active in organic co-solvents.
abstract: The widespread use of organic solvents in industrial processes has focused in recent years on the utility of "green" solvents - those with less harmful environmental, health, and safety properties - such as methanol and formamide. However, protein enzymes, regarded as green catalysts, are often incompatible with organic solvents. Herein, we have explored the oxidative properties of a Fe(III)-heme, or hemin, utilizing catalytic DNA (heme·DNAzyme) in different green solvent-water mixtures. We find that the peroxidase and peroxygenase activities of the heme·DNAzyme are strongly enhanced in 20-30% v/v methanol or formamide, relative to water alone. Protic solvent content of >30% v/v gradually diminishes heme·DNAzyme catalytic activity; however, the heme·DNAzyme is still active in as high as 80% v/v methanol. In contrast to protic solvents, aqueous dimethylformamide solutions largely inhibit heme·DNAzyme activity. In view of the strong catalytic activity of heme·DNAzyme in aqueous methanol, we were able to determine that a 60% v/v methanol-water mixture gives the most optimal yield of the dibenzothiophene sulfoxide (DBTO) oxidation product of petroleum-derived dibenzothiophene (DBT). The high product yield reflects both DNAzyme catalysis and a high substrate availability. Overall, these results emphasize the excellent promise of G-quadruplex forming DNA catalysts in application to "greener" industrial chemistry. This article is part of a Special Issue entitled "G-quadruplex" Guest Editor: Dr. Concetta Giancola and Dr. Daniela Montesarchio.
authors.affiliation: Department of Molecular Biology & Biochemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Canale
authors.affiliation: Department of Molecular Biology & Biochemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada; Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada. Electronic address: sen@sfu.ca.
authors.forename: Dipankar
authors.initials: D
authors.lastname: Sen
mesh_terms: D001665:Binding Sites; D002384:Catalysis; D002942:Circular Dichroism; D021881:DNA, Catalytic / Q000737:chemistry / Q000378:metabolism*; D004126:Dimethylformamide / Q000737:chemistry; D004789:Enzyme Activation; D005559:Formamides / Q000737:chemistry; D054856:G-Quadruplexes; D006151:Guanosine / Q000737:chemistry / Q000378:metabolism*; D006427:Hemin / Q000737:chemistry / Q000378:metabolism*; D008024:Ligands; D000432:Methanol / Q000737:chemistry; D009841:Oligonucleotides / Q000737:chemistry / Q000378:metabolism*; D009930:Organic Chemicals / Q000737:chemistry*; D010084:Oxidation-Reduction; D011485:Protein Binding; D012997:Solvents / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship; D014867:Water / Q000737:chemistry; D020002:tert-Butyl Alcohol / Q000737:chemistry
chemical_list: D021881:DNA, Catalytic; D005559:Formamides; D008024:Ligands; D009841:Oligonucleotides; D009930:Organic Chemicals; D012997:Solvents; D014867:Water; D006151:Guanosine; C031066:formamide; D006427:Hemin; D004126:Dimethylformamide; D020002:tert-Butyl Alcohol; D000432:Methanol
keywords: DNAzyme; G-quadruplex; Heme; Organic solvents; Oxidation