Browsing by Author "Qin, Z."
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Item Fluorine speciation analysis using reverse phase liquid chromatography coupled off-line to continuum source molecular absorption spectrometry (CS-MAS): Identification and quantification of novel fluorinated organic compounds in environmental and biological samples(Analytical Chemistry, 2012-06) Qin, Z.; McNee, D.; Gleisner, H.; Raab, A.; Kyeremeh, K.; Jaspars, M.; Krupp, E.; Deng, H.; Feldmann, J.Figure Persented: Driven by increasing demand for the monitoring of industrial perfluorinated compounds (PFCs), the identification of novel fluorine containing compounds (FOCs) and the tracking of organofluorine drugs and their degradation products, there is a clear need for sensitive, fluorine-specific detection of unknown FOCs. Here we report the first ever direct fluorine-specific (speciation) method; capable of individually detecting untargeted FOCs in environmental and biological samples through the application of continuum source molecular absorption spectrometry (CS-MAS) using a commercial CS-AAS. Two model FOCs (2,4,6, trifluorobenzoic acid (TFBA) and 5-fluoroindol-5-carboxylic acid (FICA)) were used, achieving fluorine-specific detection across a range of 0.1 to 300 ng/mL fluorine, corresponding to a limit of detection of 4 pg F and 5.26 nM for both compounds. Both TFBA and FICA showed a similar response to CS-MAS detection, potentially enabling the quantification of fluorine content in novel FOCs without having molecular standards available. This paper also reports the use of reverse-phase high performance liquid chromatography (RP-HPLC) coupled off-line with CS-MAS for the identification of single organofluorines in a mixture of FOCs via fraction collection. The linear range of both FOCs was determined to be from 1 to 500 ng/mL. The limits of detection of those species were just above 1 ng/mL (100 pg) and can therefore compete with targeted analytical methods such as ESI-MS. Finally, as a proof of principle the analysis of a fluoride-containing groundwater sample from Ghana demonstrated that this method can be used in the detection of novel FOCs, with identification achieved through parallel ESI-MS. Coupled HPLC-CS-MAS/ESI-MS is the first analytical methodology capable of selectively detecting and identifying novel FOCs, making possible the quantification of all fluorine containing compounds in one sample. This is the necessary analytical requirement to perform fluoronomics. © 2012 American Chemical Society.Item Identification of a fluorometabolite from Streptomyces sp. MA37: (2R3S4S)-5-fluoro-2,3,4-trihydroxypentanoic acid†(Chemical Science, 2015) Ma, L.; Bartholome, A.; Tong, M.H.; Qin, Z.; Yu, Y.; Shepherd, T.; Kyerematen, K.; Deng, H.; Hagan, D.O.(2R3S4S)-5-Fluoro-2,3,4-trihydroxypentanoic acid (5-FHPA) has been discovered as a new fluorometabolite in the soil bacterium Streptomyces sp. MA37. Exogenous addition of 5-fluoro-5-deoxy-D-ribose (5-FDR) into the cell free extract of MA37 demonstrated that 5-FDR was an intermediate to a range of unidentified fluorometabolites, distinct from fluoroacetate (FAc) and 4-fluorothreonine (4-FT). Bioinformatics analysis allowed identification of a gene cluster (fdr), encoding a pathway to the biosynthesis of 5-FHPA. Over-expression and in vitro assay of FdrC indicated that FdrC is a NAD+ dependent dehydrogenase responsible for oxidation of 5-FDR into 5-fluoro-5-deoxy-lactone, followed by hydrolysis to 5-FHPA. The identity of 5-FHPA in the fermentation broth was confirmed by synthesis of a reference compound and then co-correlation by 19F-NMR and GC-MS analysis. The occurrence of 5-FHPA proves the existence of a new fluorometabolite pathway.Item Identification of fluorinases from streptomyces sp MA37, norcardia brasiliensis, and actinoplanes sp N902-109 by genome mining(ChemBioChem, 2014) Deng, H.; Ma, L.; Bandaranayaka, N.; Qin, Z.; Mann, G.; Kyeremeh, K.; Yu, Y.; Shepherd, T.; Naismith, J.H.; O'Hagan, D.The fluorinase is an enzyme that catalyses the combination of S-adenosyl-L-methionine (SAM) and a fluoride ion to generate 5′-fluorodeoxy adenosine (FDA) and L-methionine through a nucleophilic substitution reaction with a fluoride ion as the nucleophile. It is the only native fluorination enzyme that has been characterised. The fluorinase was isolated in 2002 from Streptomyces cattleya, and, to date, this has been the only source of the fluorinase enzyme. Herein, we report three new fluorinase isolates that have been identified by genome mining. The novel fluorinases from Streptomyces sp. MA37, Nocardia brasiliensis, and an Actinoplanes sp. have high homology (80-87 % identity) to the original S. cattleya enzyme. They all possess a characteristic 21-residue loop. The three newly identified genes were overexpressed in E. coli and shown to be fluorination enzymes. An X-ray crystallographic study of the Streptomyces sp. MA37 enzyme demonstrated that it is almost identical in structure to the original fluorinase. Culturing of the Streptomyces sp. MA37 strain demonstrated that it not only also elaborates the fluorometabolites, fluoroacetate and 4-fluorothreonine, similar to S. cattleya, but this strain also produces a range of unidentified fluorometabolites. These are the first new fluorinases to be reported since the first isolate, over a decade ago, and their identification extends the range of fluorination genes available for fluorination biotechnology. Get on the fluor! The fluorinase enzyme from Streptomyces cattleya was identified in 2002 as the only fluorination enzyme known in biochemistry. Three additional fluorinases expressed through bacterial genome mining are now reported. These new fluorinases extend the range of genes available for developing fluorination biotechnology. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Item Identification of Fluorinases from Streptomyces sp MA37,Norcardia brasiliensis, and Actinoplanes sp N902-109 by Genome Mining(ChemBioChem 15, 364 – 368, 2014) Deng, H.; Ma, L.; Bandaranayaka, N.; Qin, Z.; Mann, G.; Kyeremeh, K.; Yu, Y.; Shepherd, T; Naismith, J.H.; Hagan, D.O.The fluorinase is an enzyme that catalyses the combination of S-adenosyl-l-methionine (SAM) and a fluoride ion to generate 5’-fluorodeoxy adenosine (FDA) and l-methionine through a nucleophilic substitution reaction with a fluoride ion as the nucleophile. It is the only native fluorination enzyme that has been characterised. The fluorinase was isolated in 2002 from Streptomyces cattleya, and, to date, this has been the only source of the fluorinase enzyme. Herein, we report three new fluorinase isolates that have been identified by genome mining. The novel fluorinases from Streptomyces sp. MA37, Nocardia brasiliensis, and an Actinoplanes sp. have high homology (80–87% identity) to the original S. cattleya enzyme. They all possess a characteristic 21-residue loop. The three newly identified genes were overexpressed in E. coli and shown to be fluorination enzymes. An X-ray crystallographic study of the Streptomyces sp. MA37 enzyme demonstrated that it is almost identical in structure to the original fluorinase. Culturing of the Streptomyces sp. MA37 strain demonstrated that it not only also elaborates the fluorometabolites, fluoroacetate and 4-fluorothreonine, similar to S. cattleya, but this strain also produces a range of unidentified fluorometabolites. These are the first new fluorinases to be reported since the first isolate, over a decade ago, and their identification extends the range of fluorination genes available for fluorination biotechnology.