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Yang T, Hu Q, Liu Y, Xu R, Wang D, Chang Z, Jin M, Huang J. Biochemical characteristics and potential application of a thermostable starch branching enzyme from Bacillus licheniformis. AMB Express 2023; 13:8. [PMID: 36662316 PMCID: PMC9859979 DOI: 10.1186/s13568-023-01511-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 01/08/2023] [Indexed: 01/21/2023] Open
Abstract
Slowly digestible starch (SDS) has attracted increasing attention for its function of preventing metabolic diseases. Based on transglycosylation, starch branching enzymes (1,4-α-glucan branching enzymes, GBEs, EC 2.4.1.18) can be used to regulate the digestibility of starch. In this study, a GBE gene from Bacillus licheniformis (bl-GBE) was cloned, expressed, purified, and characterized. Sequence analysis and structural modeling showed that bl-GBE belong to the glycoside hydrolase 13 (GH13) family, with which its active site residues were conserved. The bl-GBE was highly active at 80 °C and a pH range of 7.5-9.0, and retained 90% of enzyme activity at 70 °C for 16 h. bl-GBE also showed high substrate specificity (80.88 U/mg) on potato starch. The stability and the changes of the secondary structure of bl-GBE at different temperature were determined by circular dichroism (CD) spectroscopy. The CD data showed a loss of 20% of the enzyme activity at high temperatures (80 °C), due to the decreased content of the α -helix in the secondary structure. Furthermore, potato starch treated with bl-GBE (300 U/g starch) showed remarkable increase in stability, solubility, and significant reduction viscosity. Meanwhile, the slowly digestible starch content of bl-GBE modified potato starch increased by 53.03% compared with native potato starch. Our results demonstrated the potential applications of thermophilic bl-GBE in food industries.
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Affiliation(s)
- Ting Yang
- grid.22069.3f0000 0004 0369 6365School of Life Sciences, East China Normal University, Shanghai, 200241 China
| | - Qianyu Hu
- grid.22069.3f0000 0004 0369 6365School of Life Sciences, East China Normal University, Shanghai, 200241 China
| | - Yu Liu
- grid.22069.3f0000 0004 0369 6365School of Life Sciences, East China Normal University, Shanghai, 200241 China
| | - Rui Xu
- grid.22069.3f0000 0004 0369 6365School of Life Sciences, East China Normal University, Shanghai, 200241 China
| | - Dongrui Wang
- grid.22069.3f0000 0004 0369 6365School of Life Sciences, East China Normal University, Shanghai, 200241 China
| | - Zhongyi Chang
- grid.22069.3f0000 0004 0369 6365School of Life Sciences, East China Normal University, Shanghai, 200241 China
| | - Mingfei Jin
- grid.22069.3f0000 0004 0369 6365School of Life Sciences, East China Normal University, Shanghai, 200241 China
| | - Jing Huang
- grid.22069.3f0000 0004 0369 6365School of Life Sciences, East China Normal University, Shanghai, 200241 China
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Jansen JWA, Haaker MW, Zaal EA, Helms JB. Retinyl Ester Analysis by Orbitrap Mass Spectrometry. Methods Mol Biol 2023; 2669:67-77. [PMID: 37247055 DOI: 10.1007/978-1-0716-3207-9_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Retinoids are light-sensitive molecules that are normally detected by UV absorption techniques. Here we describe the identification and quantification of retinyl ester species by high-resolution mass spectrometry. Retinyl esters are extracted by the method of Bligh and Dyer and subsequently separated by HPLC in runs of 40 min. The retinyl esters are identified and quantified by mass spectrometry analysis. This procedure enables the highly sensitive detection and characterization of retinyl esters in biological samples such as hepatic stellate cells.
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Affiliation(s)
- Jeroen W A Jansen
- Division of Cell Biology, Metabolism & Cancer, Faculty of Veterinary Medicine, Department of Biomolecular Health Sciences, Utrecht University, Utrecht, The Netherlands
| | - Maya W Haaker
- Division of Cell Biology, Metabolism & Cancer, Faculty of Veterinary Medicine, Department of Biomolecular Health Sciences, Utrecht University, Utrecht, The Netherlands
| | - Esther A Zaal
- Division of Cell Biology, Metabolism & Cancer, Faculty of Veterinary Medicine, Department of Biomolecular Health Sciences, Utrecht University, Utrecht, The Netherlands
| | - J Bernd Helms
- Division of Cell Biology, Metabolism & Cancer, Faculty of Veterinary Medicine, Department of Biomolecular Health Sciences, Utrecht University, Utrecht, The Netherlands.
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Comparison between the enzymatic activity, structure and substrate binding of mouse and human lecithin retinol acyltransferase. Biochem Biophys Res Commun 2019; 519:832-837. [PMID: 31561851 DOI: 10.1016/j.bbrc.2019.09.061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 09/15/2019] [Indexed: 11/22/2022]
Abstract
Lecithin retinol acyltransferase (LRAT) is involved in the visual cycle where it catalyzes the formation of all-trans retinyl ester. The mouse animal model has been widely used to study LRAT. Primary sequence alignment shows 80% identity and 90% similarity between human and mouse LRAT. However, human LRAT has a proline at position 173 (hLRAT (P173)) while an arginine can be found at this position for the mouse protein (mLRAT (R173)). Moreover, residue 173 is important for the human protein since a substitution mutation of this residue to a leucine (P173L-hLRAT) caused night blindness in a patient. The present study was thus undertaken to determine whether mouse and human LRAT have a similar enzymatic activity, structure and substrate binding affinity using a truncated form of LRAT (tLRAT). The enzymatic activity and binding affinity to the substrate, all-trans retinol, of mtLRAT (R173) were found to be 2.7- and 3.9-fold lower, respectively, than that of htLRAT (P173). Moreover, the enzymatic activity of P173L-htLRAT is 6.3-fold lower compared to that of htLRAT (P173). Furthermore, a significant difference was observed between the intrinsic fluorescence emission as well as between the circular dichroism spectra of mtLRAT (R173) and htLRAT (P173). In addition, mtLRAT proteins are less thermostable than htLRAT proteins, which suggests that structural differences exist between the mouse and human proteins. Altogether, these data strongly suggest that the much lower catalytic activity of mtLRAT (R173) compared to that of htLRAT (P173) mostly results from differences between their structure, predominantly revealed by their dissimilar thermal stability, as well as their efficiency to bind all-trans retinol. Therefore, conclusions regarding the behavior of human LRAT based on measurements performed with mouse LRAT must be made with caution. Also, the much lower enzymatic activity of P173L-htLRAT compared to that of htLRAT (P173) might explain the night blindness of a patient carrying this mutation.
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Bernier SC, Cantin L, Salesse C. Systematic analysis of the expression, solubility and purification of a passenger protein in fusion with different tags. Protein Expr Purif 2018; 152:92-106. [DOI: 10.1016/j.pep.2018.07.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/13/2018] [Accepted: 07/19/2018] [Indexed: 12/31/2022]
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Ajat M, Molenaar M, Brouwers JFHM, Vaandrager AB, Houweling M, Helms JB. Hepatic stellate cells retain the capacity to synthesize retinyl esters and to store neutral lipids in small lipid droplets in the absence of LRAT. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:176-187. [PMID: 27815220 DOI: 10.1016/j.bbalip.2016.10.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 10/07/2016] [Accepted: 10/28/2016] [Indexed: 01/20/2023]
Abstract
Hepatic stellate cells (HSCs) play an important role in liver physiology and under healthy conditions they have a quiescent and lipid-storing phenotype. Upon liver injury, HSCs are activated and rapidly lose their retinyl ester-containing lipid droplets. To investigate the role of lecithin:retinol acyltransferase (LRAT) and acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) in retinyl ester synthesis and lipid droplet dynamics, we modified LC-MS/MS procedures by including multiple reaction monitoring allowing unambiguous identification and quantification of all major retinyl ester species. Quiescent primary HSCs contain predominantly retinyl palmitate. Exogenous fatty acids are a major determinant in the retinyl ester species synthesized by activated HSCs and LX-2 cells, indicating that HSCs shift their retinyl ester synthesizing capacity from LRAT to DGAT1 during activation. Quiescent LRAT-/- HSCs retain the capacity to synthesize retinyl esters and to store neutral lipids in lipid droplets ex vivo. The median lipid droplet size in LRAT-/- HSCs (1080nm) is significantly smaller than in wild type HSCs (1618nm). This is a consequence of an altered lipid droplet size distribution with 50.5±9.0% small (≤700nm) lipid droplets in LRAT-/- HSCs and 25.6±1.4% large (1400-2100nm) lipid droplets in wild type HSC cells. Upon prolonged (24h) incubation, the amounts of small (≤700nm) lipid droplets strongly increased both in wild type and in LRAT-/- HSCs, indicating a dynamic behavior in both cell types. The absence of retinyl esters and reduced number of lipid droplets in LRAT-deficient HSCs in vivo will be discussed.
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Affiliation(s)
- Mokrish Ajat
- Department of Biochemistry & Cell Biology, Faculty of Veterinary Medicine, and Institute of Biomembranes, Utrecht University, P.O. Box 80176, 3508 TD Utrecht, The Netherlands
| | - Martijn Molenaar
- Department of Biochemistry & Cell Biology, Faculty of Veterinary Medicine, and Institute of Biomembranes, Utrecht University, P.O. Box 80176, 3508 TD Utrecht, The Netherlands
| | - Jos F H M Brouwers
- Department of Biochemistry & Cell Biology, Faculty of Veterinary Medicine, and Institute of Biomembranes, Utrecht University, P.O. Box 80176, 3508 TD Utrecht, The Netherlands
| | - Arie B Vaandrager
- Department of Biochemistry & Cell Biology, Faculty of Veterinary Medicine, and Institute of Biomembranes, Utrecht University, P.O. Box 80176, 3508 TD Utrecht, The Netherlands
| | - Martin Houweling
- Department of Biochemistry & Cell Biology, Faculty of Veterinary Medicine, and Institute of Biomembranes, Utrecht University, P.O. Box 80176, 3508 TD Utrecht, The Netherlands
| | - J Bernd Helms
- Department of Biochemistry & Cell Biology, Faculty of Veterinary Medicine, and Institute of Biomembranes, Utrecht University, P.O. Box 80176, 3508 TD Utrecht, The Netherlands.
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Mezaki Y, Fujimi TJ, Senoo H, Matsuura T. The coordinated action of lecithin:retinol acyltransferase and cellular retinol-binding proteins for regulation of vitamin A esterification. Med Hypotheses 2016; 88:60-2. [PMID: 26880640 DOI: 10.1016/j.mehy.2016.01.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 01/20/2016] [Indexed: 11/25/2022]
Abstract
Vitamin A is a fat-soluble vitamin required for many physiological functions. The intracellular transport of vitamin A is assisted by proteins called cellular retinol-binding proteins (CRBP I/II). The absorption, storage and usage of vitamin A are regulated by a protein called lecithin:retinol acyltransferase (LRAT), a retinol-related enzyme that transfers an acyl group derived from an sn-1 position of phosphatidylcholine to retinol. LRAT is a member of the protein family which includes HRAS-like tumor suppressors (HRASLS). However, the HRASLS proteins never use retinol as an acyl acceptor. The mechanisms underlying the different substrate specificities between LRAT and HRASLS proteins are unknown. We propose in this report that LRAT physically interacts with CRBP and the LRAT-CRBP complex represents the binding pockets for both an acyl group and retinol, thus assuring the substrate specificity of LRAT.
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Affiliation(s)
- Yoshihiro Mezaki
- Department of Laboratory Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
| | - Takahiko J Fujimi
- Department of Laboratory Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan; Faculty of Health and Nutrition, Bunkyo University, 1100 Namegaya, Chigasaki, Kanagawa 253-8550, Japan
| | - Haruki Senoo
- Department of Cell Biology and Morphology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan
| | - Tomokazu Matsuura
- Department of Laboratory Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan
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Eichmann TO, Grumet L, Taschler U, Hartler J, Heier C, Woblistin A, Pajed L, Kollroser M, Rechberger G, Thallinger GG, Zechner R, Haemmerle G, Zimmermann R, Lass A. ATGL and CGI-58 are lipid droplet proteins of the hepatic stellate cell line HSC-T6. J Lipid Res 2015; 56:1972-84. [PMID: 26330055 PMCID: PMC4583087 DOI: 10.1194/jlr.m062372] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Indexed: 12/31/2022] Open
Abstract
Lipid droplets (LDs) of hepatic stellate cells (HSCs) contain large amounts of vitamin A [in the form of retinyl esters (REs)] as well as other neutral lipids such as TGs. During times of insufficient vitamin A availability, RE stores are mobilized to ensure a constant supply to the body. To date, little is known about the enzymes responsible for the hydrolysis of neutral lipid esters, in particular of REs, in HSCs. In this study, we aimed to identify LD-associated neutral lipid hydrolases by a proteomic approach using the rat stellate cell line HSC-T6. First, we loaded cells with retinol and FAs to promote lipid synthesis and deposition within LDs. Then, LDs were isolated and lipid composition and the LD proteome were analyzed. Among other proteins, we found perilipin 2, adipose TG lipase (ATGL), and comparative gene identification-58 (CGI-58), known and established LD proteins. Bioinformatic search of the LD proteome for α/β-hydrolase fold-containing proteins revealed no yet uncharacterized neutral lipid hydrolases. In in vitro activity assays, we show that rat (r)ATGL, coactivated by rat (r)CGI-58, efficiently hydrolyzes TGs and REs. These findings suggest that rATGL and rCGI-58 are LD-resident proteins in HSCs and participate in the mobilization of both REs and TGs.
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Affiliation(s)
- Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Lukas Grumet
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Ulrike Taschler
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Jürgen Hartler
- Bioinformatics, Institute for Knowledge Discovery, Graz University of Technology, Graz, Austria
| | - Christoph Heier
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Aaron Woblistin
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Laura Pajed
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Manfred Kollroser
- Institute of Forensic Medicine, Medical University of Graz, Graz, Austria
| | - Gerald Rechberger
- Institute of Molecular Biosciences, University of Graz, Graz, Austria BioTechMed-Graz, Graz, Austria OMICS Center, Graz, Austria
| | - Gerhard G Thallinger
- Bioinformatics, Institute for Knowledge Discovery, Graz University of Technology, Graz, Austria BioTechMed-Graz, Graz, Austria OMICS Center, Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Günter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
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