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Nakamura K, Iizuka R, Nishi S, Yoshida T, Hatada Y, Takaki Y, Iguchi A, Yoon DH, Sekiguchi T, Shoji S, Funatsu T. Culture-independent method for identification of microbial enzyme-encoding genes by activity-based single-cell sequencing using a water-in-oil microdroplet platform. Sci Rep 2016; 6:22259. [PMID: 26915788 PMCID: PMC4768102 DOI: 10.1038/srep22259] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/10/2016] [Indexed: 12/22/2022] Open
Abstract
Environmental microbes are a great source of industrially valuable enzymes with potent and unique catalytic activities. Unfortunately, the majority of microbes remain unculturable and thus are not accessible by culture-based methods. Recently, culture-independent metagenomic approaches have been successfully applied, opening access to untapped genetic resources. Here we present a methodological approach for the identification of genes that encode metabolically active enzymes in environmental microbes in a culture-independent manner. Our method is based on activity-based single-cell sequencing, which focuses on microbial cells showing specific enzymatic activities. First, at the single-cell level, environmental microbes were encapsulated in water-in-oil microdroplets with a fluorogenic substrate for the target enzyme to screen for microdroplets that contain microbially active cells. Second, the microbial cells were recovered and subjected to whole genome amplification. Finally, the amplified genomes were sequenced to identify the genes encoding target enzymes. Employing this method, we successfully identified 14 novel β-glucosidase genes from uncultured bacterial cells in marine samples. Our method contributes to the screening and identification of genes encoding industrially valuable enzymes.
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Affiliation(s)
- Kazuki Nakamura
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ryo Iizuka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shinro Nishi
- Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka-shi, Kanagawa 237-0061, Japan
| | - Takao Yoshida
- Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka-shi, Kanagawa 237-0061, Japan
| | - Yuji Hatada
- Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka-shi, Kanagawa 237-0061, Japan
| | - Yoshihiro Takaki
- Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka-shi, Kanagawa 237-0061, Japan
| | - Ayaka Iguchi
- Department of NanoscieWnce and Nanoengineering (ASE Graduate School), Waseda University, 3-4-1 Okubo, Shinju-ku, Tokyo 169-8555, Japan
| | - Dong Hyun Yoon
- Department of NanoscieWnce and Nanoengineering (ASE Graduate School), Waseda University, 3-4-1 Okubo, Shinju-ku, Tokyo 169-8555, Japan
| | - Tetsushi Sekiguchi
- Research Organization for Nano &Life Innovation, Waseda University, 513, Waseda-tsurumaki-cho, Shinjuku-ku, Tokyo, 162-0041, Japan
| | - Shuichi Shoji
- Department of NanoscieWnce and Nanoengineering (ASE Graduate School), Waseda University, 3-4-1 Okubo, Shinju-ku, Tokyo 169-8555, Japan
| | - Takashi Funatsu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Santosh Kumar B, Raghavendra Guru Prasad A, Madhu G, Raveendra Reddy P, Ravindranath L. Synthesis and in silico studies of pyrrolidine sulfonamide based dipeptides as β-gluscosidase inhibitors. ANNALES PHARMACEUTIQUES FRANÇAISES 2014; 72:256-66. [DOI: 10.1016/j.pharma.2014.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 02/11/2014] [Accepted: 02/17/2014] [Indexed: 01/14/2023]
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Abstract
The early detection of many human diseases is crucial if they are to be treated successfully. Therefore, the development of imaging techniques that can facilitate early detection of disease is of high importance. Changes in the levels of enzyme expression are known to occur in many diseases, making their accurate detection at low concentrations an area of considerable active research. Activatable fluorescent probes show immense promise in this area. If properly designed they should exhibit no signal until they interact with their target enzyme, reducing the level of background fluorescence and potentially endowing them with greater sensitivity. The mechanisms of fluorescence changes in activatable probes vary. This review aims to survey the field of activatable probes, focusing on their mechanisms of action as well as illustrating some of the in vitro and in vivo settings in which they have been employed.
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Affiliation(s)
- Christopher R Drake
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, Box 0946, San Francisco, CA, 94107, USA
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Valenzano KJ, Khanna R, Powe AC, Boyd R, Lee G, Flanagan JJ, Benjamin ER. Identification and characterization of pharmacological chaperones to correct enzyme deficiencies in lysosomal storage disorders. Assay Drug Dev Technol 2011; 9:213-35. [PMID: 21612550 PMCID: PMC3102255 DOI: 10.1089/adt.2011.0370] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many human diseases result from mutations in specific genes. Once translated, the resulting aberrant proteins may be functionally competent and produced at near-normal levels. However, because of the mutations, the proteins are recognized by the quality control system of the endoplasmic reticulum and are not processed or trafficked correctly, ultimately leading to cellular dysfunction and disease. Pharmacological chaperones (PCs) are small molecules designed to mitigate this problem by selectively binding and stabilizing their target protein, thus reducing premature degradation, facilitating intracellular trafficking, and increasing cellular activity. Partial or complete restoration of normal function by PCs has been shown for numerous types of mutant proteins, including secreted proteins, transcription factors, ion channels, G protein-coupled receptors, and, importantly, lysosomal enzymes. Collectively, lysosomal storage disorders (LSDs) result from genetic mutations in the genes that encode specific lysosomal enzymes, leading to a deficiency in essential enzymatic activity and cellular accumulation of the respective substrate. To date, over 50 different LSDs have been identified, several of which are treated clinically with enzyme replacement therapy or substrate reduction therapy, although insufficiently in some cases. Importantly, a wide range of in vitro assays are now available to measure mutant lysosomal enzyme interaction with and stabilization by PCs, as well as subsequent increases in cellular enzyme levels and function. The application of these assays to the identification and characterization of candidate PCs for mutant lysosomal enzymes will be discussed in this review. In addition, considerations for the successful in vivo use and development of PCs to treat LSDs will be discussed.
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Urban DJ, Zheng W, Goker-Alpan O, Jadhav A, Lamarca ME, Inglese J, Sidransky E, Austin CP. Optimization and validation of two miniaturized glucocerebrosidase enzyme assays for high throughput screening. Comb Chem High Throughput Screen 2009; 11:817-24. [PMID: 19075603 DOI: 10.2174/138620708786734244] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Glucocerebrosidase (GC) catalyzes the hydrolysis of beta-glucocerebroside to glucose and ceramide in lysosomes. Mutations in the glucocerebrosidase gene (GBA) result in Gaucher disease, an autosomal recessive lysosomal storage disorder. Many of the mutations encountered in patients with Gaucher disease are missense alterations that may cause misfolding, decreased stability and/or mistrafficking of this lysosomal protein. Some inhibitors of GC have been shown to act as chemical chaperones, stabilizing the conformation of mutant proteins and thus restoring their function. High throughput screening (HTS) of small molecule libraries for such compounds with potential for chaperone therapy requires an accurate, reproducible and sensitive assay method. We have adapted and optimized two fluorogenic GC enzyme assays and miniaturized them into the 1536-well plate format for HTS. The two substrates, 4-methylumbelliferyl beta-D-glucopyranoside and resorufin beta-D-glucopyranoside, have K(m) values of 768 microM and 33 microM, respectively, and different emission spectra. Paired screening with the two assays helps to eliminate false inference of activity due to autofluorescence or fluorescence quenching by the screened compounds. Test screens with the LOPAC library indicated that both assays were robust for HTS, and gave comparable results for GC inhibitor activities. These two assays can be used to identify both GC activators and inhibitors with potential therapeutic value.
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Affiliation(s)
- Daniel J Urban
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-3708, USA
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Kohen E, Gatt S, Schachtschabel A, Schachtschabel DO, Kohen C, Agmon V, Hirschberg JG, Monti M. Microspectrofluorometry and fluorescence imaging in the study of human cytopathology. Microsc Res Tech 2000; 51:469-80. [PMID: 11074618 DOI: 10.1002/1097-0029(20001201)51:5<469::aid-jemt10>3.0.co;2-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The study of energy pools and dynamics of specific pathways in living cells by microspectrofluorometry and fluorescence imaging produces spectral and topographic images characterizing structural and functional changes associated with cytopathology. Microspectro-fluorometry and fluorescence imaging have been applied, together with organelle morphometry to a number of cells mimicking certain cytopathologies, including melanoma cells, long-term malignant cells, and gene-defective cells. These investigations of cellular pathology indicate that there is a convergence of various physiopathological processes. Cellular states that have similarities include senescence, detoxification, and transformation. While the NAD(P)H metabolic transients have been studied before, our emphasis in this article is on very rapidly scanned fluorescence images related to organelle integration and photoinduced cellular senescence.
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Affiliation(s)
- E Kohen
- Department of Biology, University of Miami, Coral Gables, Florida 33124, USA
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van Es HH, Veldwijk M, Havenga M, Valerio D. A flow cytometric assay for lysosomal glucocerebrosidase. Anal Biochem 1997; 247:268-71. [PMID: 9177687 DOI: 10.1006/abio.1997.2090] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A flow cytometric assay is described for the determination of glucocerebrosidase (GC) activity using fluorescein di-beta-glucopyranoside (FDGlu). Fluorescent product is formed upon intracellular hydrolysis of FDGlu and is measured in the FL1 channel of a flow cytometer. We show that the assay is specific for lysosomal beta-glucosidase or glucocerebrosidase (1) by concentration-dependent inhibition of GC activity by conditurol-beta-epoxide (CBE), a specific irreversible inhibitor; (2) by the absence of activity in fibroblasts isolated from patients with Gaucher disease; (3) correction of the biochemical Gaucher phenotype in these cells is detectable following gene transfer and can be inhibited by CBE; (4) murine fibroblasts transfected with the human GC cDNA and expressing 1.5- to 2.5-fold higher levels of human GC in in vitro assays can be distinguished from nontransfected cells in mixing experiments; and (5) preincubation of GC expressing cells with the lysosomotropic compound chloroquine leads to a loss of the GC-mediated increase in fluorescence supporting lysosomal localization of the FDGlu hydrolyzing enzyme. This flow cytometric GC assay will be useful for monitoring GC activity at the single cell level and can be used for monitoring the efficacy of Gaucher patient treatments such as enzyme supplementation and gene therapy. Finally, our findings suggest that other lysosomal enzymes can be measured in this way using alternate fluorescein derivatives.
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Levade T, Leruth M, Graber D, Moisand A, Vermeersch S, Salvayre R, Courtoy PJ. In situ assay of acid sphingomyelinase and ceramidase based on LDL-mediated lysosomal targeting of ceramide-labeled sphingomyelin. J Lipid Res 1996. [DOI: 10.1016/s0022-2275(20)37457-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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