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Feng K, Qi N, Jin Q, Gao L, Zhang J, Tian Q. Cloning and characterization of four enzymes responsible for cyclohexylamine degradation from Paenarthrobacter sp. TYUT067. Protein Expr Purif 2022; 198:106136. [PMID: 35760252 DOI: 10.1016/j.pep.2022.106136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 06/11/2022] [Accepted: 06/22/2022] [Indexed: 01/25/2023]
Abstract
Paenarthrobacter sp. TYUT067 is a soil bacterium that can degrade and use cyclohexylamine as the sole source of carbon and energy. However, the responsible enzymes involved in cyclohexylamine degradation by TYUT067 have not been cloned and characterized in detail yet. In this study, four possible cyclohexylamine degradation genes, one cyclohexylamine oxidase (Pachao), two cyclohexanone monooxygenases (Pachms) and one lactone hydrolase (Pamlh) were successfully cloned and heterologous expressed in Escherichia coli T7 host cells. The four enzymes were purified and characterized. The optimal pH and temperature of the purified enzymes toward their own substrates were 7.0 (PaCHAO), 8.0 (PaCHM1), 9.0 (PaCHM2 and PaMLH) and 30 °C (PaCHAO and PaMLH), 40 °C (PaCHM2) and 45 °C (PaCHM1), respectively, with KM of 1.1 mM (PaCHAO), 0.1 mM (PaCHM1), 0.1 mM (PaCHM2) and 0.8 mM (PaMLH), and yielding a catalytic efficiency kcat/KM of 16.1 mM-1 s-1 (PaCHAO), 1.0 mM-1 s-1 (PaCHM1), 5.0 mM-1 s-1 (PaCHM2) and 124.4 mM-1 s-1 (PaMLH). In vitro mimicking the cyclohexylamine degradation pathway was conducted by using the combined three cyclohexylamine degradation enzymes (PaCHAO, PaCHM2 and PaMLH) with 10-50 mM cyclohexylamine, 100% conversion of cyclohexylamine could be finished within 12 h without any detected intermediates. The current study confirmed the enzymes responsible for cyclohexylamine degradation in TYUT067 for the first time, provide basic information for further investigation and application of these specific enzymes in pollution control.
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Affiliation(s)
- Kaiqing Feng
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, PR China
| | - Ning Qi
- Department of Biological and Pharmaceutical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, PR China
| | - Qi Jin
- Department of Biological and Pharmaceutical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, PR China
| | - Lili Gao
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, PR China.
| | - Jiandong Zhang
- Department of Biological and Pharmaceutical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, PR China
| | - Qi Tian
- College of Civil Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, PR China
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Ásgeirsson B, Markússon S, Hlynsdóttir SS, Helland R, Hjörleifsson JG. X-ray crystal structure of Vibrio alkaline phosphatase with the non-competitive inhibitor cyclohexylamine. Biochem Biophys Rep 2020; 24:100830. [PMID: 33102813 PMCID: PMC7569297 DOI: 10.1016/j.bbrep.2020.100830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 10/06/2020] [Indexed: 11/13/2022] Open
Abstract
Background Para-nitrophenyl phosphate, the common substrate for alkaline phosphatase (AP), is available as a cyclohexylamine salt. Here, we report that cyclohexylamine is a non-competitive inhibitor of APs. Methods Cyclohexylamine inhibited four different APs. Co-crystallization with the cold-active Vibrio AP (VAP) was performed and the structure solved. Results Inhibition of VAP fitted a non-competitive kinetic model (Km unchanged, Vmax reduced) with IC50 45.3 mM at the pH optimum 9.8, not sensitive to 0.5 M NaCl, and IC50 27.9 mM at pH 8.0, where the addition of 0.5 M NaCl altered the inhibition to the level observed at pH 9.8. APs from E. coli and calf intestines were less sensitive to cyclohexylamine, whereas an Antarctic bacterial AP was similar to VAP in this respect. X-ray crystallography at 2.3 Å showed two binding sites, one in the active site channel and another at the surface close to dimer interface. Antarctic bacterial AP and VAP have Trp274 in common in their active-sites, that takes part in binding cyclohexylamine. VAP variants W274A, W274K, and W274H gave IC50 values of 179 mM, 188 mM and 187 mM, respectively, at pH 9.8. Conclusions The binding of cyclohexylamine in locations at the dimeric interface and/or in the active site of APs may delay product release or reduce the rate of catalytic step(s) involving conformational changes and intersubunit communications. General significance Cyclohexylamine is a common chemical in industries and used as a counterion in substrates for alkaline phosphatase, a clinically important and common enzyme in the biosphere. Cyclohexylamine inhibits alkaline phosphatase activity non-competitively. X-ray structure was solved that shows cyclohexylamine bound to alkaline phosphatase at two sites. Alkaline phosphatases from four different organisms bind cyclohexylamine with varying affinity.
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Affiliation(s)
- Bjarni Ásgeirsson
- Department of Biochemistry, Science Institute, University of Iceland, Dunhagi 3, 107 Reykjavik, Iceland
| | - Sigurbjörn Markússon
- Department of Biochemistry, Science Institute, University of Iceland, Dunhagi 3, 107 Reykjavik, Iceland
| | - Sigríður S Hlynsdóttir
- Department of Biochemistry, Science Institute, University of Iceland, Dunhagi 3, 107 Reykjavik, Iceland
| | - Ronny Helland
- NorStruct, Department of Chemistry, Faculty of Science and Technology, UiT - the Arctic University of Norway, NO-9037, Tromsø, Norway
| | - Jens G Hjörleifsson
- Department of Biochemistry, Science Institute, University of Iceland, Dunhagi 3, 107 Reykjavik, Iceland
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Yu HL, Li T, Chen FF, Luo XJ, Li A, Yang C, Zheng GW, Xu JH. Bioamination of alkane with ammonium by an artificially designed multienzyme cascade. Metab Eng 2018; 47:184-189. [PMID: 29477859 DOI: 10.1016/j.ymben.2018.02.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 11/22/2017] [Accepted: 02/20/2018] [Indexed: 11/17/2022]
Abstract
Biocatalytic C-H amination is one of the most challenging tasks. C-H amination reaction can hardly be driven efficiently by solely one enzyme so far. Thus, enzymatic synergy represents an alternative strategy. Herein, we report an "Artificially Bioamination Pathway" for C-H amination of cyclohexane as a model substrate. Three enzymes, a monooxygenase P450BM3 mutant, an alcohol dehydrogenase ScCR from Streptomyces coelicolor and an amine dehydrogenase EsLeuDH from Exiguobacterium sibiricum, constituted a clean cascade reaction system with easy product isolation. Two independent cofactor regeneration systems were optimized to avoid interference from the endogenous NADH oxidases in the host E. coli cells. Based on a stepwise pH adjustment and ammonium supplement strategy, and using an in vitro mixture of cell-free extracts of the three enzymes, cyclohexylamine was produced in a titer of 14.9 mM, with a product content of up to 92.5%. Furthermore, designer cells coexpressing the three required enzymes were constructed and their capability of alkane bio-amination was examined. This artificially designed bioamination paves an attractive approach for enzymatic synthesis of amines from accessible and cheap alkanes.
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Affiliation(s)
- Hui-Lei Yu
- Laboratory of Biocatalysis and Synthetic Biotechnology, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China.
| | - Tuo Li
- Laboratory of Biocatalysis and Synthetic Biotechnology, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China
| | - Fei-Fei Chen
- Laboratory of Biocatalysis and Synthetic Biotechnology, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China
| | - Xiao-Jing Luo
- Laboratory of Biocatalysis and Synthetic Biotechnology, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China
| | - Aitao Li
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, 368 Friendship Avenue, Wuchang District, Wuhan, Hubei, 430062, China
| | - Chao Yang
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education and State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
| | - Gao-Wei Zheng
- Laboratory of Biocatalysis and Synthetic Biotechnology, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China
| | - Jian-He Xu
- Laboratory of Biocatalysis and Synthetic Biotechnology, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China.
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Sorouraddin SM, Farajzadeh MA, Okhravi T. Cyclohexylamine as extraction solvent and chelating agent in extraction and preconcentration of some heavy metals in aqueous samples based on heat-induced homogeneous liquid-liquid extraction. Talanta 2017; 175:359-365. [PMID: 28842003 DOI: 10.1016/j.talanta.2017.07.065] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/21/2017] [Accepted: 07/22/2017] [Indexed: 11/24/2022]
Abstract
A new sample preparation method has been developed for extraction and preconcentration of some heavy metal cations in aqueous samples using cyclohexylamine-based homogeneous liquid-liquid microextraction. In the proposed method, cyclohexylamine was used as both the complexing agent and the extraction solvent. For this purpose, cyclohexylamine at µL level was initially added into an aqueous solution containing Co(II), Ni(II), and Cu(II) ions which was placed in a glass test tube. The mixture was shaken for forming a homogeneous solution. Then sodium chloride was added to the solution. After shaking manually again, the test tube was placed in a water bath thermostated at 70°C. Due to lower solubility of cyclohexylamine at the elevated temperature, a cloudy solution was formed. The fine droplets of cyclohexylamine containing cation-cyclohexylamine complexes were collected on the top of the aqueous phase by centrifuging. The enriched analytes in the upper phase were determined by graphite furnace atomic absorption spectrometry. Several variables possibly affecting the extraction efficiency were investigated and optimized. Under the optimum conditions the calibration curves were linear in the ranges of 80-1000, 40-700, and 80-800ngL-1 for Co2+, Ni2+, and Cu2+, respectively. Repeatability of the proposed method, expressed as relative standard deviation, ranged from 3.3% to 5.2% (n = 6, C = 200ngL-1). Moreover, the obtained detection limits of the selected analytes were in the range of 15.3-37.7ngL-1. The accuracy of the developed procedure was verified by analyzing a certified reference material, namely NRCC-SLRS4 Riverine water. Finally, the proposed method was successfully applied for the simultaneous analysis of the selected analytes in environmental water samples.
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Affiliation(s)
| | - Mir Ali Farajzadeh
- Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran; Engineering Faculty, Near East University, 99138 Nicosia, North Cyprus, Mersin 10, Turkey
| | - Tohid Okhravi
- Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran
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Scoccianti V, Iacobucci M, Speranza A, Antognoni F. Over-accumulation of putrescine induced by cyclohexylamine interferes with chromium accumulation and partially restores pollen tube growth in Actinidia deliciosa. Plant Physiol Biochem 2013; 70:424-432. [PMID: 23835360 DOI: 10.1016/j.plaphy.2013.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 06/12/2013] [Indexed: 06/02/2023]
Abstract
Both trivalent and hexavalent chromium, i.e., Cr(III) and Cr(VI), respectively, were previously demonstrated to affect in vitro germination and ultrastructure of kiwifruit (Actinidia deliciosa) pollen. In the present work, the response to chromium in germinating pollen was evaluated in terms of changes in the polyamine profile. Slight, though significant, increases in free spermidine and spermine occurred after exposure to Cr(III), while the levels remained almost unchanged after Cr(VI) treatment. The spermidine synthase inhibitor cyclohexylamine (CHA) caused a dramatic increase in free putrescine in both chromium-treated and untreated samples, while spermidine content was not affected. Interestingly, CHA positively affected the performance of chromium-treated pollen by partially, though significantly, restoring pollen tube growth. The major growth recovery was registered with 1 mM CHA in the presence of Cr(VI), concomitant with a considerable reduction in uptake of the metal. Conversely, endogenous calcium levels were more heavily affected in Cr(III)-treated pollen. The effect of CHA on production of reactive oxygen species also varied depending on the chromium species. The response of pollen to the CHA-induced putrescine excess was compared with that exerted by an exogenous supply of the same diamine. Results show that in Cr(III)-treated pollen, putrescine over-accumulation induced by CHA exerted similar effects as exogenous putrescine, while this was not true in the Cr(VI) treatment. It appears that the diamine was able to improve pollen tolerance to metal stress through different mechanisms, mostly depending upon the chromium species, namely via reduced metal uptake or by substituting for calcium.
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Affiliation(s)
- Valeria Scoccianti
- Dipartimento di Scienze della Terra, della Vita e dell'Ambiente, Sezione di Biologia Vegetale, Università di Urbino Carlo Bo, via Bramante 28, 61029 Urbino, Italy.
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