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Sun Q, Gao H, Liu Y, Wang L, Huang J. Validation and stability analysis of guanine deaminase assay kit. Heliyon 2024; 10:e36210. [PMID: 39224279 PMCID: PMC11367462 DOI: 10.1016/j.heliyon.2024.e36210] [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: 03/13/2024] [Revised: 06/13/2024] [Accepted: 08/12/2024] [Indexed: 09/04/2024] Open
Abstract
Guanine deaminase (GD)plays important roles in the diagnosis of liver function. However, there is no totally rapid and simple for the eatimation of GD activity in clinical application. Herein, we have constructed an enzymatic assay system with highly sensitive and strong stability for quantification of GD activity by highly double enzyme-coupling (xanthine oxidase and uric acid oxidase) and adding compound stabilizer in GD kit. In this study, we validated parameters, including reagent blank, sensitivity, accuracy, inter-batch difference, intra-batch difference, linear range. Furthermore, composite stabilizers, containing gentamicin sulfate, bovine serum albumin, and mannitol, were selected to improve stability of GD kit during long-term storage. The experimental results showed that the absorbance of the reagent blank was <0.2, the mean recovery rate was 103 %, the inter-batch and intra-batch diffeerence were <15 %, The linearity range was 0 U/L-50 U/L (R2 > 0.99). All indicators met the kit requirements for clinical applications. When gentamicin sulfate, bovine serum albumin, and mannitol were used as a stabilizer, the kit remained stable for 12 months without significant loss of enzymatic activity. These results indicated that GD kit possesses high sensitivity and strong stability, which can be used for routine biochemical applications and is of great significance for the diagnosis and differential diagnosis of liver diseases.
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Affiliation(s)
- Qiang Sun
- Department of Laboratory Medicine, The First Hospital of Jilin University, Changchun, Jilin Province, PR China
| | - Haidi Gao
- Department of Laboratory Medicine, The First Hospital of Jilin University, Changchun, Jilin Province, PR China
| | - Yong Liu
- Genetic Diagnosis Center, The First Hospital of Jilin University, Changchun, Jilin Province, PR China
| | - Liqiang Wang
- Department of Laboratory Medicine, The First Hospital of Jilin University, Changchun, Jilin Province, PR China
| | - Jing Huang
- Department of Laboratory Medicine, The First Hospital of Jilin University, Changchun, Jilin Province, PR China
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Guan Q, Kong W, Tan B, Zhu W, Akter T, Li J, Tian J, Chen S. Multiomics unravels potential molecular switches in the C 3 to CAM transition of Mesembryanthemum crystallinum. J Proteomics 2024; 299:105145. [PMID: 38431086 DOI: 10.1016/j.jprot.2024.105145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/21/2024] [Accepted: 02/28/2024] [Indexed: 03/05/2024]
Abstract
Mesembryanthemum crystallinum (common ice plant), a facultative CAM plant, shifts from C3 to CAM photosynthesis under salt stress, enhancing water use efficiency. Here we used transcriptomics, proteomics, and targeted metabolomics to profile molecular changes during the diel cycle of C3 to CAM transition. The results confirmed expected changes associated with CAM photosynthesis, starch biosynthesis and degradation, and glycolysis/gluconeogenesis. Importantly, they yielded new discoveries: 1) Transcripts displayed greater circadian regulation than proteins. 2) Oxidative phosphorylation and inositol methylation may play important roles in initiating the transition. 3) V-type H+-ATPases showed consistent transcriptional regulation, aiding in vacuolar malate uptake. 4) A protein phosphatase 2C, a major component in the ABA signaling pathway, may trigger the C3 to CAM transition. Our work highlights the potential molecular switches in the C3 to CAM transition, including the potential role of ABA signaling. SIGNIFICANCE: The common ice plant is a model facultative CAM plant, and under stress conditions it can shift from C3 to CAM photosynthesis within a three-day period. However, knowledge about the molecular changes during the transition and the molecular switches enabling the transition is lacking. Multi-omic analyses not only revealed the molecular changes during the transition, but also highlighted the importance of ABA signaling, inositol methylation, V-type H+-ATPase in initiating the shift. The findings may explain physiological changes and nocturnal stomatal opening, and inform future synthetic biology effort in improving crop water use efficiency and stress resilience.
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Affiliation(s)
- Qijie Guan
- Department of Biology, University of Mississippi, Oxford, MS 38677, USA
| | - Wenwen Kong
- College of Life Sciences, Northeast Agricultural University, Harbin 150040, China
| | - Bowen Tan
- Department of Biology, University of Mississippi, Oxford, MS 38677, USA
| | - Wei Zhu
- Institute of Basic Medicine and Cancer, Chinese Academy of Sciences, Hangzhou 310002, China
| | - Tahmina Akter
- Department of Biology, University of Mississippi, Oxford, MS 38677, USA
| | - Jing Li
- College of Life Sciences, Northeast Agricultural University, Harbin 150040, China
| | - Jingkui Tian
- Institute of Basic Medicine and Cancer, Chinese Academy of Sciences, Hangzhou 310002, China
| | - Sixue Chen
- Department of Biology, University of Mississippi, Oxford, MS 38677, USA.
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Li CH, Tu YC, Wen MF, Tien HJ, Yen HE. Exogenous myo-inositol increases salt tolerance and accelerates CAM induction in the early juvenile stage of the facultative halophyte Mesembryanthemum crystallinum but not in the late juvenile stage. FUNCTIONAL PLANT BIOLOGY : FPB 2023; 50:363-377. [PMID: 36949582 DOI: 10.1071/fp22285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 02/21/2023] [Indexed: 05/03/2023]
Abstract
Mesembryanthemum crystallinum L. (ice plant) develops salt tolerance during the transition from the juvenile to the adult stage through progressive morphological, physiological, biochemical, and molecular changes. Myo -inositol is the precursor for the synthesis of compatible solute D-pinitol and promotes Na+ transport in ice plants. We previously showed that supplying myo -inositol to 9-day-old seedlings alleviates salt damage by coordinating the expression of genes involved in inositol synthesis and transport, affecting osmotic adjustment and the Na/K balance. In this study, we examined the effects of myo -inositol on physiological parameters and inositol-related gene expression in early- and late-stage juvenile plants. The addition of myo -inositol to salt-treated, hydroponically grown late juvenile plants had no significant effects on growth or photosynthesis. In contrast, supplying exogenous myo -inositol to salt-treated early juvenile plants increased leaf biomass, relative water content, and chlorophyll content and improved PSII activity and CO2 assimilation. The treatment combining high salt and myo -inositol synergistically induced the expression of myo -inositol phosphate synthase (INPS ), myo -inositol O -methyltransferase (IMT ), and inositol transporters (INTs ), which modulated root-to-shoot Na/K ratio and increased leaf D-pinitol content. The results indicate that sufficient myo -inositol is a prerequisite for high salt tolerance in ice plant.
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Affiliation(s)
- Cheng-Hsun Li
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
| | - Yun-Cheng Tu
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
| | - Meng-Fang Wen
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
| | - Hsing-Jung Tien
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
| | - Hungchen Emilie Yen
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
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Ge YD, Guo YT, Jiang LL, Wang HH, Hou SL, Su FZ. Enzymatic Characterization and Coenzyme Specificity Conversion of a Novel Dimeric Malate Dehydrogenase from Bacillus subtilis. Protein J 2023; 42:14-23. [PMID: 36534341 PMCID: PMC9761052 DOI: 10.1007/s10930-022-10087-0] [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] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
Malate is an important material to various industrials and clinical applications. Bacillus subtilis is a widely used biocatalyst tool for chemical production. However, the specific enzymatic properties of malate dehydrogenase from Bacillus subtilis (BsMDH) remain largely unknown. In the present study, BsMDH was cloned, recombinantly expressed and purified to test its enzymatic properties. The molecular weight of single unit of BsMDH was 34,869.7 Da. Matrix-Assisted Laser-Desorption Ionization-Time-of-Flight Mass Spectrometry and gel filtration analysis indicated that the recombinant BsMDH could form dimers. The kcat/Km values of oxaloacetate and NADH were higher than those of malate and NAD+, respectively, indicating a better catalysis in the direction of malate synthesis than the reverse. Furthermore, six BsMDH mutants were constructed with the substitution of amino acids at the coenzyme binding site. Among them, BsMDH-T7 showed a greatly higher affinity and catalysis efficiency to NADPH than NADH with the degree of alteration of 2039, suggesting the shift of the coenzyme dependence from NADH to NADPH. In addition, BsMDH-T7 showed a relatively lower Km value, but a higher kcat and kcat/Km than NADPH-dependent MDHs from Thermus flavus and Corynebacterium glutamicum. Overall, these results indicated that BsMDH and BsMDH-T7 mutant might be promising enzymes for malate production.
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Affiliation(s)
- Ya-Dong Ge
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, People's Republic of China.
| | - Yi-Tian Guo
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, People's Republic of China
| | - Lu-Lu Jiang
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, People's Republic of China
| | - Hui-Hui Wang
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, People's Republic of China
| | - Shao-Lin Hou
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, People's Republic of China
| | - Feng-Zhi Su
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, People's Republic of China
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5
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Li CH, Tien HJ, Wen MF, Yen HE. Myo-inositol transport and metabolism participate in salt tolerance of halophyte ice plant seedlings. PHYSIOLOGIA PLANTARUM 2021; 172:1619-1629. [PMID: 33511710 DOI: 10.1111/ppl.13353] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 01/06/2021] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
Myo-inositol and its metabolic derivatives such as pinitol, galactinol, and raffinose affect growth and development and are also involved in stress adaptation. Previous studies have identified myo-inositol transporters (INTs) as transporters of Na+ from root to shoot in the halophyte ice plant (Mesembryanthemum crystallinum). We found that the supply of myo-inositol could alleviate the dehydration effects of salt-stressed ice plant seedlings by decreasing the Na/K ratio in roots and increasing the Na/K ratio in shoots. Analyses of the uptake of exogenous myo-inositol revealed that ice plant seedlings contained intrinsic high-affinity transporters and inducible low-affinity uptake systems. The presence of Na+ facilitated both high- and low-affinity myo-inositol uptake. Six INT genes were identified from the ice plant transcriptome and named McINT1a, 1b, 2, 4a, 4b, and 4c, according to the classification of the Arabidopsis INT family. In seedlings treated with myo-inositol, salt, or myo-inositol plus salt, the expression patterns of all McINT members differed in shoot and root, which indicates organ-specific regulation of McINTs by salt and myo-inositol. The expression of McINT2, 4a, 4b, and 4c was induced by salt stress in shoot and root, but that of McINT1a and 1b was salt-induced only in shoot. The expression of pinitol biosynthesis gene IMT1 was induced by salt and myo-inositol, and their combination had a synergistic effect on the accumulation of pinitol. Supply of myo-inositol to salt-treated seedlings alleviated the detrimental effects by maintaining a low root Na/K ratio and providing precursors for the synthesis of compatible solute to maintain the osmotic balance.
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Affiliation(s)
- Cheng-Hsun Li
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Hsing-Jung Tien
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Meng-Fang Wen
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Hungchen Emilie Yen
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
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Scafaro AP, Fan Y, Posch BC, Garcia A, Coast O, Atkin OK. Responses of leaf respiration to heatwaves. PLANT, CELL & ENVIRONMENT 2021; 44:2090-2101. [PMID: 33534189 DOI: 10.1111/pce.14018] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/21/2021] [Accepted: 01/23/2021] [Indexed: 06/12/2023]
Abstract
Mitochondrial respiration (R) is central to plant physiology and responds dynamically to daily short-term temperature changes. In the longer-term, changes in energy demand and membrane fluidity can decrease leaf R at a common temperature and increase the temperature at which leaf R peaks (Tmax ). However, leaf R functionality is more susceptible to short-term heatwaves. Catalysis increases with rising leaf temperature, driving faster metabolism and leaf R demand, despite declines in photosynthesis restricting assimilate supply and growth. Proteins denature as temperatures increase further, adding to maintenance costs. Excessive heat also inactivates respiratory enzymes, with a concomitant limitation on the capacity of the R system. These competing push-and-pull factors are responsible for the diminishing acceleration in leaf R rate as temperature rises. Under extreme heat, membranes become overly fluid, and enzymes such as the cytochrome c oxidase are impaired. Such changes can lead to over-reduction of the energy system culminating in reactive oxygen species production. This ultimately leads to the total breakdown of leaf R, setting the limit of leaf survival. Understanding the heat stress responses of leaf R is imperative, given the continued rise in frequency and intensity of heatwaves and the importance of R for plant fitness and survival.
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Affiliation(s)
- Andrew P Scafaro
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Yuzhen Fan
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Bradley C Posch
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Andres Garcia
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Onoriode Coast
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
- Natural Resources Institute, Agriculture, Health and Environment Department, University of Greenwich, Kent, UK
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
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Vuorinen E, Valtonen S, Eskonen V, Kariniemi T, Jakovleva J, Kopra K, Härmä H. Sensitive Label-Free Thermal Stability Assay for Protein Denaturation and Protein-Ligand Interaction Studies. Anal Chem 2020; 92:3512-3516. [PMID: 32013400 PMCID: PMC7145280 DOI: 10.1021/acs.analchem.9b05712] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
In modern biochemistry,
protein stability and ligand interactions are of high interest. These
properties are often studied with methods requiring labeled biomolecules,
as the existing methods utilizing luminescent external probes suffer
from low sensitivity. Currently available label-free technologies,
e.g., thermal shift assays, circular dichroism, and differential scanning
calorimetry, enable studies on protein unfolding and protein–ligand
interactions (PLI). Unfortunately, the required micromolar protein
concentration increases the costs and predisposes these methods for
spontaneous protein aggregation. Here, we report a time-resolved luminescence
method for protein unfolding and PLI detection with nanomolar sensitivity.
The Protein-Probe method is based on highly luminescent europium chelate-conjugated
probe, which is the key component in sensing the hydrophobic regions
exposed to solution after protein unfolding. With the same Eu-probe,
we also demonstrate ligand-interaction induced thermal stabilization
with model proteins. The developed Protein-Probe method provides a
sensitive approach overcoming the problems of the current label-free
methodologies.
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Affiliation(s)
- Emmiliisa Vuorinen
- Department of Chemistry, University of Turku, Vatselankatu 2, 20500 Turku, Finland
| | - Salla Valtonen
- Department of Chemistry, University of Turku, Vatselankatu 2, 20500 Turku, Finland
| | - Ville Eskonen
- Department of Chemistry, University of Turku, Vatselankatu 2, 20500 Turku, Finland
| | - Taru Kariniemi
- Department of Chemistry, University of Turku, Vatselankatu 2, 20500 Turku, Finland
| | - Jelena Jakovleva
- Department of Chemistry, University of Turku, Vatselankatu 2, 20500 Turku, Finland
| | - Kari Kopra
- Department of Chemistry, University of Turku, Vatselankatu 2, 20500 Turku, Finland
| | - Harri Härmä
- Department of Chemistry, University of Turku, Vatselankatu 2, 20500 Turku, Finland
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Pupel P, Szablińska-Piernik J, Lahuta LB. Two-step d-ononitol epimerization pathway in Medicago truncatula. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:237-250. [PMID: 31215085 DOI: 10.1111/tpj.14439] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/31/2019] [Accepted: 06/10/2019] [Indexed: 06/09/2023]
Abstract
Methylated inositol, d-pinitol (3-O-methyl-d-chiro-inositol), is a common constituent in legumes. It is synthesized from myo-inositol in two reactions: the first reaction, catalyzed by myo-inositol-O-methyltransferase (IMT), consists of a transfer of a methyl group from S-adenosylmethionine to myo-inositol with the formation of d-ononitol, while the second reaction, catalyzed by d-ononitol epimerase (OEP), involves epimerization of d-ononitol to d-pinitol. To identify the genes involved in d-pinitol biosynthesis in a model legume Medicago truncatula, we conducted a BLAST search on its genome using soybean IMT cDNA as a query and found putative IMT (MtIMT) gene. Subsequent co-expression analysis performed on publicly available microarray data revealed two potential OEP genes: MtOEPA, encoding an aldo-keto reductase and MtOEPB, encoding a short-chain dehydrogenase. cDNAs of all three genes were cloned and expressed as recombinant proteins in E. coli. In vitro assays confirmed that putative MtIMT enzyme catalyzes methylation of myo-inositol to d-ononitol and showed that MtOEPA enzyme has NAD+ -dependent d-ononitol dehydrogenase activity, while MtOEPB enzyme has NADP+ -dependent d-pinitol dehydrogenase activity. Both enzymes are required for epimerization of d-ononitol to d-pinitol, which occurs in the presence of NAD+ and NADPH. Introduction of MtIMT, MtOEPA, and MtOEPB genes into tobacco plants resulted in production of d-ononitol and d-pinitol in transformants. As this two-step pathway of d-ononitol epimerization is coupled with a transfer of reducing equivalents from NADPH to NAD+ , we speculate that one of the functions of this pathway might be regeneration of NADP+ during drought stress.
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Affiliation(s)
- Piotr Pupel
- Department of Plant Physiology, Genetics and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn, Poland
| | - Joanna Szablińska-Piernik
- Department of Plant Physiology, Genetics and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn, Poland
| | - Lesław B Lahuta
- Department of Plant Physiology, Genetics and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn, Poland
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Abstract
Symbiosomes are a unique structural entity that performs the role of biological nitrogen fixation, an energy-demanding process that is the primary entryway of fixed nitrogen into the biosphere. Symbiosomes result from the infection of specific rhizobial strains into the roots of an appropriate leguminous host plant forming an organ referred to as a nodule. Within the infected plant cells of the nodule, the rhizobia are encased within membrane-bounded structures that develop into symbiosomes. Mature symbiosomes create an environment that allows the rhizobia to differentiate into a nitrogen-fixing form called bacteroids. The bacteroids are surrounded by the symbiosome space, which is populated by proteins from both eukaryotic and prokaryotic symbionts, suggesting this space is the quintessential component of symbiosis: an inter-kingdom environment with the single purpose of symbiotic nitrogen fixation. Proteins associated with the symbiosome membrane are largely plant-derived proteins and are non-metabolic in nature. The proteins of the symbiosome space are mostly derived from the bacteroid with annotated functions of carbon metabolism, whereas relatively few are involved in nitrogen metabolism. An appreciable portion of both the eukaryotic and prokaryotic proteins in the symbiosome are also ‘moonlighting’ proteins, which are defined as proteins that perform roles unrelated to their annotated activities when found in an unexpected physiological environment. The essential functions of symbiotic nitrogen fixation of the symbiosome are performed by co-operative interactions of proteins from both symbionts some of which may be performing unexpected roles.
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Ribeiro EDS, Centeno DDC, Figueiredo-Ribeiro RDC, Fernandes KVS, Xavier-Filho J, Oliveira AEA. Free cyclitol, soluble carbohydrate and protein contents in Vigna unguiculata and Phaseolus vulgaris bean sprouts. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:4273-4278. [PMID: 21413793 DOI: 10.1021/jf104979m] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Seeds sprouts have been used as a good source of basic nutrients and nutraceutical compounds. The high nutritional value of seeds derives from the deposition of compounds during development. However some of these molecules are used in metabolic processes like germination, which leads to a considerable variation in their concentrations once these events are completed. In this work, we investigate the levels of inositols (myo-inositol, D-pinitol and ononitol), soluble carbohydrates and proteins in cotyledons of Phaseolus vulgaris and Vigna unguiculata sprouts. Sprouting increased myo-inositol and glucose content and reduction of raffinose and ononitol was observed. The protein levels increased in P. vulgaris and decreased in V. unguiculata sprouting. The level of sucrose was maintained in both sprouts. D-Pinitol was detected only in quiescent seeds. Our results suggested that bean sprout is an important source of proteins, sucrose, glucose and myo-inositol. Additionally, bean sprouts have low levels of raffinose, an antinutritional compound.
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Affiliation(s)
- Elane da Silva Ribeiro
- Laboratório de Química e Função de Proteínas e Peptídeos-LQFPP, Centro de Biociências e Biotecnologia-CBB, Universidade Estadual do Norte Fluminense Darcy Ribeiro-UENF, Campos dos Goytacazes, RJ, Brazil
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11
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Garland S, Goheen S, Donald P, McDonald L, Campbell J. Application of Derivatization Gas Chromatography/Mass Spectrometry for the Identification and Quantitation of Pinitol in Plant Roots. ANAL LETT 2009. [DOI: 10.1080/00032710903082531] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Arndt SK, Livesley SJ, Merchant A, Bleby TM, Grierson PF. Quercitol and osmotic adaptation of field-grown Eucalyptus under seasonal drought stress. PLANT, CELL & ENVIRONMENT 2008; 31:915-924. [PMID: 18315535 DOI: 10.1111/j.1365-3040.2008.01803.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
This study investigated the role of quercitol in osmotic adjustment in field-grown Eucalyptus astringens Maiden subject to seasonal drought stress over the course of 1 year. The trees grew in a native woodland and a farm plantation in the semi-arid wheatbelt region of south Western Australia. Plantation trees allocated relatively more biomass to leaves than woodland trees, but they suffered greater drought stress over summer, as indicated by lower water potentials, CO(2)assimilation rates and stomatal conductances. In contrast, woodland trees had relatively fewer leaves and suffered less drought stress. Plantation trees under drought stress engaged in osmotic adjustment, but woodland trees did not. Quercitol made a significant contribution to osmotic adjustment in drought-stressed trees (25% of total solutes), and substantially more quercitol was measured in the leaves of plantation trees (5% dry matter) than in the leaves of woodland trees (2% dry matter). We found no evidence that quercitol was used as a carbon storage compound while starch reserves were depleted under drought stress. Differences in stomatal conductance, biomass allocation and quercitol production clearly indicate that E. astringens is both morphologically and physiologically 'plastic' in response to growth environment, and that osmotic adjustment is only one part of a complex strategy employed by this species to tolerate drought.
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Affiliation(s)
- Stefan K Arndt
- School of Forest and Ecosystem Science, The University of Melbourne, 500 Yarra Boulevard, Richmond, Vic. 3121, Australia.
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14
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Ortbauer M, Popp M. Functional role of polyhydroxy compounds on protein structure and thermal stability studied by circular dichroism spectroscopy. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2008; 46:428-434. [PMID: 18343146 DOI: 10.1016/j.plaphy.2008.02.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Indexed: 05/26/2023]
Abstract
Polyhydroxy compounds such as cyclitols, acyclic polyols and sugars are produced by a wide variety of organisms under stressful conditions in order to protect macromolecular structure. Plants undergoing abiotic stresses like heat and dehydration accumulate enormous amounts of polyhydroxy compounds (up to 400 mM) in their cellular tissues. Not only do they serve as osmoprotectants ("compatible solutes"), they also protect membrane structure and preserve enzymatic activity. To gain further insight into the mechanism of protein protection by polyhydroxy compounds, we examined the structural and thermal stability of six model proteins (bovine serum albumin, glutamine synthetase of Escherichia coli, malate dehydrogenase of pig heart, SH2 domain of phospholipaseCgamma1, SH2_Myc and GST_MycMax fusion proteins) upon the addition of various polyhydroxy compounds by circular dichroism spectroscopy. Our results show that D-pinitol (1D-3-O-methyl-chiro-inositol), L-quebrachitol (1L-2-O-methyl-chiro-inositol), myo-inositol, D-chiro-inositol, mannitol, glucose and trehalose promoted improved structural and thermal stability for each protein, whereas conduritol (1,4/2,3-cyclohexanetetrol) and glycerol were not effective. An increase in the midpoint denaturation temperature (T(m)) of 3.3 degrees C to 4.7 degrees C was observed for each protein upon the addition of 400 mM myo-inositol. Although the apparent T(m) of each protein was shifted by the addition of polyhydroxy compounds, the influence seems to be dependent on attributes like the protein surface topology, the hydration shell and on the nature of the protective solute, as well as on its concentration. The O-methylated cyclitols D-pinitol and L-quebrachitol were more effective preservatives than the less hydrophobic non-methylated myo-inositol and D-chiro-inositol. Amongst various polyhydroxy compounds, hydrophobic cyclitols were the most effective stabilizers.
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Affiliation(s)
- Martina Ortbauer
- Department of Biomolecular Structural Chemistry, University of Vienna, Campus Vienna Biocenter 5, Vienna, Austria.
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Jakobsen AN, Aasen IM, Strøm AR. Endogenously synthesized (-)-proto-quercitol and glycine betaine are principal compatible solutes of Schizochytrium sp. strain S8 (ATCC 20889) and three new isolates of phylogenetically related thraustochytrids. Appl Environ Microbiol 2007; 73:5848-56. [PMID: 17660311 PMCID: PMC2074927 DOI: 10.1128/aem.00610-07] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report that endogenously synthesized (-)-proto-quercitol (1D-1,3,4/2,5-cyclohexanepentol) and glycine betaine were the principal compatible solutes of Schizochytrium sp. strain S8 (ATCC 20889) and three new osmotolerant isolates of thraustochytrids (strains T65, T66, and T67). The compatible solutes were identified and quantified by use of nuclear magnetic resonance spectroscopy, and their identity was confirmed by mass spectroscopy and measurement of the specific optical rotation. The cellular content of compatible solutes increased with increasing NaCl concentration of a defined medium. (-)-proto-Quercitol was the dominating solute at all NaCl concentrations tested (0.25 to 1.0 M), e.g., cells of S8 and T66 stressed with 1.0 M NaCl accumulated about 500 micromol (-)-proto-quercitol and 100 micromol glycine betaine per g dry weight. To our knowledge, (-)-proto-quercitol has previously been found only in eucalyptus. The 18S rRNA gene sequences of the four (-)-proto-quercitol-producing strains showed 99% identity, and they displayed the same fatty acid profile. The only polyunsaturated fatty acids accumulated were docosahexaenoic acid (78%) and docosapentaenoic acid (22%). A less osmotolerant isolate (strain T29), which was closely phylogenetically related to Thraustochytrium aureum (ATCC 34304), did not contain (-)-proto-quercitol or glycine betaine. Thus, the level of osmotolerance and the osmolyte systems vary among thraustochytrids.
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Affiliation(s)
- Anita N Jakobsen
- Department of Biotechnology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
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