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Gautam S, Gupta MN. Solid state fluorescence of proteins in high throughput mode and its applications. F1000Res 2019; 2:82. [PMID: 30997030 PMCID: PMC6441877 DOI: 10.12688/f1000research.2-82.v2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/07/2019] [Indexed: 11/24/2022] Open
Abstract
Direct comparison between fluorescence spectra of a sample in solution and solid state form is valuable to monitor the changes in protein structure when it is “dried” or immobilized on a solid surface (for biocatalysis or sensor applications). We describe here a simple method for recording fluorescence emission spectra of protein powders without using any dedicated accessory for solid samples in a high-throughput format. The 96-well plate used in our studies, was coated black from all the sides and the excitation and emission paths are identical and are from the top of the well. These two features minimize scatter and provide fairly noise free spectra. Even then the fluorescence intensity may be dependent upon many factors such as the extent of protein aggregation, morphology and sizes of the protein particles. Hence, (changes in) λ
max emission may be a more reliable metric in the case of fluorescence spectra of proteins in the solid state. However, any large changes in the intensity could indicate changes in the microenvironment of the fluorophore. The fluorescence emission spectra were blue-shifted (4 to 9 nm), showed an increase in the intensity for different proteins studied upon lyophilization, and were similar to what has been reported by others using available commercial accessories for solid state samples. After validating that our method worked just as well as the dedicated accessories, we applied the method to compare the fluorescence emission spectra of α-chymotrypsin in solution, precipitated form, and the lyophilized powder form. We further examined the fluorescence emission spectra of green fluorescent protein (GFP) in solution and solid form. We also analyzed fluorescence resonance energy transfer (FRET) between tryptophan (Trp57) and the cyclic chromophore of GFP. These findings pointed towards the change in the microenvironment around the cyclic chromophore in GFP upon lyophilization.
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Affiliation(s)
- Saurabh Gautam
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Munishwar N Gupta
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi, 110016, India
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Xu L, Liu X, Yin Z, Liu Q, Lu L, Xiao M. Site-directed mutagenesis of α-l-rhamnosidase from Alternaria sp. L1 to enhance synthesis yield of reverse hydrolysis based on rational design. Appl Microbiol Biotechnol 2016; 100:10385-10394. [DOI: 10.1007/s00253-016-7676-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 06/06/2016] [Accepted: 06/11/2016] [Indexed: 12/19/2022]
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Zhang J, Lu L, Lu L, Zhao Y, Kang L, Pang X, Liu J, Jiang T, Xiao M, Ma B. Galactosylation of steroidal saponins by β-galactosidase from Lactobacillus bulgaricus L3. Glycoconj J 2015; 33:53-62. [PMID: 26547747 DOI: 10.1007/s10719-015-9632-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 10/20/2015] [Accepted: 10/20/2015] [Indexed: 11/25/2022]
Abstract
The galactosylation of furostanosides and spirostanosides were investigated by using β-galactosidase from Lactobacillus bulgaricus L3 as a catalyst and lactose as a sugar donor. Four novel galactosylated furostanoside products (compounds 1-4) from compound F, compound G, compound I, and compound H were obtained and their structures were identified by HR-ESI-MS, 1D and 2D NMR spectra. The result showed that galactosyl moiety was found to be added to the 6-OH of the 26-O-glucosyl in these four furostanoside substrates.
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Affiliation(s)
- Jie Zhang
- Beijing Institute of Radiation Medicine, 27# Tai-ping Road, Haidian District, Beijing, 100850, China
- Ovation Health Science and Technology Co. Ltd., ENN Group, Langfang, 065001, China
| | - Lili Lu
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, 27 Shanda South Road, Jinan, 250100, China
| | - Li Lu
- Beijing Institute of Radiation Medicine, 27# Tai-ping Road, Haidian District, Beijing, 100850, China
| | - Yang Zhao
- Beijing Institute of Radiation Medicine, 27# Tai-ping Road, Haidian District, Beijing, 100850, China
| | - Liping Kang
- State Key Laboratory of Dao-di Herbs, National Resource Center of Chinese Materia Medica, China Academy of Chinese Medical Sciences, 16# Nanxiaojie, Dongcheng District, Beijing, 100700, China
| | - Xu Pang
- Beijing Institute of Radiation Medicine, 27# Tai-ping Road, Haidian District, Beijing, 100850, China
| | - Jingyuan Liu
- Beijing Institute of Radiation Medicine, 27# Tai-ping Road, Haidian District, Beijing, 100850, China
| | - Tengchuan Jiang
- Beijing Institute of Radiation Medicine, 27# Tai-ping Road, Haidian District, Beijing, 100850, China
| | - Min Xiao
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, 27 Shanda South Road, Jinan, 250100, China.
| | - Baiping Ma
- Beijing Institute of Radiation Medicine, 27# Tai-ping Road, Haidian District, Beijing, 100850, China.
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Lu L, Liu Q, Jin L, Yin Z, Xu L, Xiao M. Enzymatic Synthesis of Rhamnose Containing Chemicals by Reverse Hydrolysis. PLoS One 2015; 10:e0140531. [PMID: 26505759 PMCID: PMC4624630 DOI: 10.1371/journal.pone.0140531] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 09/28/2015] [Indexed: 11/19/2022] Open
Abstract
Rhamnose containing chemicals (RCCs) are widely occurred in plants and bacteria and are known to possess important bioactivities. However, few of them were available using the enzymatic synthesis method because of the scarcity of the α-L-rhamnosidases with wide acceptor specificity. In this work, an α-L-rhamnosidase from Alternaria sp. L1 was expressed in Pichia pastroris strain GS115. The recombinant enzyme was purified and used to synthesize novel RCCs through reverse hydrolysis in the presence of rhamnose as donor and mannitol, fructose or esculin as acceptors. The effects of initial substrate concentrations, reaction time, and temperature on RCC yields were investigated in detail when using mannitol as the acceptor. The mannitol derivative achieved a maximal yield of 36.1% by incubation of the enzyme with 0.4 M L-rhamnose and 0.2 M mannitol in pH 6.5 buffers at 55°C for 48 h. In identical conditions except for the initial acceptor concentrations, the maximal yields of fructose and esculin derivatives reached 11.9% and 17.9% respectively. The structures of the three derivatives were identified to be α-L-rhamnopyranosyl-(1→6')-D-mannitol, α-L-rhamnopyranosyl-(1→1')-β-D-fructopyranose, and 6,7-dihydroxycoumarin α-L-rhamnopyranosyl-(1→6')-β-D-glucopyranoside by ESI-MS and NMR spectroscopy. The high glycosylation efficiency as well as the broad acceptor specificity of this enzyme makes it a powerful tool for the synthesis of novel rhamnosyl glycosides.
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Affiliation(s)
- Lili Lu
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan 250100, PR China
| | - Qian Liu
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan 250100, PR China
- Academy of State Administration of Grain, Beijing 100037, PR China
| | - Lan Jin
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan 250100, PR China
| | - Zhenhao Yin
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan 250100, PR China
| | - Li Xu
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan 250100, PR China
| | - Min Xiao
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan 250100, PR China
- * E-mail:
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Mukherjee J, Mishra P, Gupta MN. Urea treated subtilisin as a biocatalyst for transformations in organic solvents. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2015.02.109] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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