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Zaman U, Khan SU, Hendi AA, Rehman KU, Badshah S, Refat MS, Alsuhaibani AM, Ullah K, Wahab A. Kinetic and thermodynamic studies of novel acid phosphatase isolated and purified from Carthamus oxyacantha seedlings. Int J Biol Macromol 2022; 224:20-31. [PMID: 36481331 DOI: 10.1016/j.ijbiomac.2022.12.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/30/2022] [Accepted: 12/04/2022] [Indexed: 12/12/2022]
Abstract
Acid phosphatase (ACP) is a key enzyme in the regulation of phosphate feeding in plants. In this study, a new ACP from C. oxyacantha was isolated to homogeneity and biochemically described for the first time. Specific activity (283 nkat/mg) was found after 2573 times purification fold and (17 %) yield. Using SDS-PAGE under denaturing and nondenaturing conditions, ACP was isolated as a monomer with a molecular weight of 36 kDa. LC-MS/MS confirmed the presence of this band, suggesting that C. oxycantha ACP is a monomer. The enzyme could also hydrolyze orthophosphate monoester with an optimal pH of 5.0 and a temperature of 50 °C. Thermodynamic parameters were also determined (Ea, ΔH°, ΔG°, and ΔS°). ACP activity was further studied in the presence of cysteine, DTT, SDS, EDTA, β-ME, Triton-X-100 H2O2, and PMSF. The enzyme had a Km of 0.167 mM and an Ea of 9 kcal/mol for p-nitrophenyl phosphate. The biochemical properties of the C. oxyacantha enzyme distinguish it from other plant acid phosphatases and give a basic understanding of ACP in C. oxyacantha. The results of this investigation also advance our knowledge about the biochemical significance of ACP in C. oxyacantha. Thermal stability over a wide pH and temperature range make it more suitable for use in harsh industrial environments. However, further structural and physiological studies are anticipated to completely comprehend its important aspects in oxyacantha species.
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Affiliation(s)
- Umber Zaman
- Institute of Chemical Sciences, Gomal University, Dera Ismail Khan, Pakistan
| | - Shahid Ullah Khan
- Department of Biochemistry, Women Medical and Dental College, Khyber Medical University KPK, Pakistan; National Key Laboratory of Crops Genetics and Improvement, PR China
| | - Awatif A Hendi
- Department of Physics, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Khalil Ur Rehman
- Institute of Chemical Sciences, Gomal University, Dera Ismail Khan, Pakistan.
| | - Syed Badshah
- Institute of Chemical Sciences, Gomal University, Dera Ismail Khan, Pakistan
| | - Moamen S Refat
- Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Amnah Mohammed Alsuhaibani
- Department of Physical Sport Science, College of Education, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Kalim Ullah
- Department of Zoology, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, Pakistan
| | - Abdul Wahab
- Department of Pharmacy, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, Pakistan
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Identification, kinetics and thermodynamic analysis of novel β-galactosidase from Convolvulus arvensis seeds: An efficient agent for delactosed milk activity. Int J Biol Macromol 2022; 220:1545-1555. [PMID: 36113598 DOI: 10.1016/j.ijbiomac.2022.09.107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 09/06/2022] [Accepted: 09/12/2022] [Indexed: 11/21/2022]
Abstract
The β-galactosidase was extracted and purified from 100 g of C. arvensis seeds using a variety of protein purification procedures such as ammonium sulphate fractionation, gel filtration, and finally chromatography on a cationic ion exchanger. The effects of metal ions, kinetics parameters, and glycoprotein nature were determined, as well as the optimal pH and temperature of the purified enzyme. With a high specific activity (72 units/mg), β-galactosidase was isolated to a 24-fold apparent electrophoretic homogeneity. The molecular mass of β-galactosidase was determined as monomeric, which was further confirmed by SDS-PAGE and MALDI-TOF/MS analysis, with a 45 kDa molecular weight. The enzyme has a Km of 0.33 mM and a Vmax of 42 μmol/min Lactose in milk was reduced by 38.5 and 70 % after 4 h of incubation with β-galactosidase from C. arvensis. The β-galactosidase thermal inactivation kinetic parameters ΔH°, ΔS°, and ΔG° were calculated, indicating that the enzyme undergoes significant unfolding events during denaturation. Using β-galactosidase from C. arvensis seeds, lactose hydrolysis in milk up to approx. 50 % was observed. The findings indicate the potential use of C. arvensis seeds for the production of low/delactosed milk for lactose-intolerant population.
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Amara AAAF. Natural Polymer Types and Applications. BIOMOLECULES FROM NATURAL SOURCES 2022:31-81. [DOI: 10.1002/9781119769620.ch2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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Zhang H, Zhang Y, Wang P, Zhang J. Transcriptome profiling of genes associated with fruit firmness in the melon variety 'Baogua' ( Cucumis melo ssp. agrestis Jeffrey). PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2022; 28:301-313. [PMID: 35400878 PMCID: PMC8943068 DOI: 10.1007/s12298-022-01131-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 01/10/2022] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
UNLABELLED Fruit firmness is an important trait of melons due to its effect on fresh fruit consumption, storage, and transport. However, information on the expression of genes influencing the fruit firmness of 'Baogua' (BG) melon (Cucumis melo ssp. agrestis Jeffrey) remains rare. This study aimed to identify the key genes associated with the firmness of BG fruit sampled at 14 and 28 days after pollination (dap) via transcriptome sequencing. A total of 1113 up-regulated and 2224 down-regulated differentially expressed genes (DEGs) were identified. The main Gene Ontology terms assigned to the DEGs were phosphotransferase activity, alcohol group as acceptor, protein phosphorylation, and protein kinase activity. The enriched KEGG pathways involving the DEGs were starch and sucrose metabolism, diterpenoid biosynthesis, plant hormone signal transduction, and MAPK signaling pathway-plant. In addition, qRT-PCR verified that four GAL genes, namely, CmGAL1-4, were differentially expressed at 0, 7, 14, 21, and 28 dap. Our data revealed that CmGAL1 expression was highest at 21 dap. However, the expression levels of CmGAL2-4 were highest at 14 dap. The sequence of CmGAL1 was similar to the sequences of homologs from melon and cucumber. Subcellular localization analysis revealed CmGAL1 was located in the cell membrane and cytoplasm. Our findings implied that fruit development at 14 dap, which is a key time-point, varies considerably from fruit development at 28 dap. Our present study provides new information on the genes associated with BG fruit firmness and help improve the storage and transport of BG fruit prior to processing. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12298-022-01131-5.
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Affiliation(s)
- Huijun Zhang
- School of Life Sciences, Huaibei Normal University, Huaibei, 235000 Anhui Province China
- Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, Anhui Jianghuai Horticulture Seeds Co., Ltd, Huaibei, 235000 Anhui Province China
| | - Yan Zhang
- School of Life Sciences, Huaibei Normal University, Huaibei, 235000 Anhui Province China
| | - Pengcheng Wang
- Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei, 230031 Anhui Province China
- Key Laboratory of Intelligent Seedling Breeding in Vegetable Factory, Ma-an-shan, 238200 Anhui Province China
- Key Laboratory of Genetic Improvement and Ecophysiology of Horticultural Crops, Hefei, 230031 Anhui Province China
| | - Jian Zhang
- Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei, 230031 Anhui Province China
- Key Laboratory of Intelligent Seedling Breeding in Vegetable Factory, Ma-an-shan, 238200 Anhui Province China
- Key Laboratory of Genetic Improvement and Ecophysiology of Horticultural Crops, Hefei, 230031 Anhui Province China
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Yadav A, Kayastha AM. Lens culinaris β-galactosidase (Lsbgal): Insights into its purification, biochemical characterization and trisaccharides synthesis. Bioorg Chem 2020; 95:103543. [DOI: 10.1016/j.bioorg.2019.103543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 12/07/2019] [Accepted: 12/21/2019] [Indexed: 12/28/2022]
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Wang D, Yeats TH, Uluisik S, Rose JKC, Seymour GB. Fruit Softening: Revisiting the Role of Pectin. TRENDS IN PLANT SCIENCE 2018; 23:302-310. [PMID: 29429585 DOI: 10.1016/j.tplants.2018.01.006] [Citation(s) in RCA: 228] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 01/16/2018] [Accepted: 01/18/2018] [Indexed: 05/18/2023]
Abstract
Fruit softening, which is a major determinant of shelf life and commercial value, is the consequence of multiple cellular processes, including extensive remodeling of cell wall structure. Recently, it has been shown that pectate lyase (PL), an enzyme that degrades de-esterified pectin in the primary wall, is a major contributing factor to tomato fruit softening. Studies of pectin structure, distribution, and dynamics have indicated that pectins are more tightly integrated with cellulose microfibrils than previously thought and have novel structural features, including branches of the main polymer backbone. Moreover, recent studies of the significance of pectinases, such as PL and polygalacturonase, are consistent with a causal relationship between pectin degradation and a major effect on fruit softening.
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Affiliation(s)
- Duoduo Wang
- Plant and Crop Science Division, School of Biosciences, University of Nottingham, Sutton Bonington, Loughborough, LE12 5RD, UK
| | - Trevor H Yeats
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA; Robert W. Holley Center for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, NY 14853, USA
| | - Selman Uluisik
- Colemerik Vocational School, Hakkari University, University Street, Karsiyaka Neighborhood 30000, Hakkari, Turkey
| | - Jocelyn K C Rose
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
| | - Graham B Seymour
- Plant and Crop Science Division, School of Biosciences, University of Nottingham, Sutton Bonington, Loughborough, LE12 5RD, UK.
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Pandey JK, Dash SK, Biswal B. Loss in photosynthesis during senescence is accompanied by an increase in the activity of β-galactosidase in leaves of Arabidopsis thaliana: modulation of the enzyme activity by water stress. PROTOPLASMA 2017; 254:1651-1659. [PMID: 27942976 DOI: 10.1007/s00709-016-1061-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 12/02/2016] [Indexed: 05/21/2023]
Abstract
The precise nature of the developmental modulation of the activity of cell wall hydrolases that breakdown the wall polysaccharides to maintain cellular sugar homeostasis under sugar starvation environment still remains unclear. In this work, the activity of β-galactosidase (EC 3.2.1.23), a cell-wall-bound enzyme known to degrade the wall polysaccharides, has been demonstrated to remarkably enhance during senescence-induced loss in photosynthesis in Arabidopsis thaliana. The enhancement in the enzyme activity reaches a peak at the terminal phase of senescence when the rate of photosynthesis is at its minimum. Although the precise nature of chemistry of the interface between the decline in photosynthesis and enhancement in the activity of the enzyme could not be fully resolved, the enhancement in its activity in dark and its suppression in light or with exogenous sugars may indicate the involvement of loss of photosynthetic production of sugars as a key factor that initiates and stimulates the activity of the enzyme. The hydrolase possibly participates in the catabolic network of cell wall polysaccharides to produce sugars for execution of energy-dependant senescence program in the background of loss of photosynthesis. Drought stress experienced by the senescing leaves accelerates the decline in photosynthesis with further stimulation in the activity of the enzyme. The stress recovery of photosynthesis and suppression of the enzyme activity on withdrawal of stress support the proposition of photosynthetic modulation of the cell-wall-bound enzyme activity.
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Affiliation(s)
- Jitendra Kumar Pandey
- Laboratory of Biochemistry and Molecular Biology, School of Life Sciences, Sambalpur University, Jyoti Vihar, Burla, Odisha, 768019, India
| | - Sidhartha Kumar Dash
- Laboratory of Biochemistry and Molecular Biology, School of Life Sciences, Sambalpur University, Jyoti Vihar, Burla, Odisha, 768019, India
| | - Basanti Biswal
- Laboratory of Biochemistry and Molecular Biology, School of Life Sciences, Sambalpur University, Jyoti Vihar, Burla, Odisha, 768019, India.
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Rahman MZ, Maeda M, Kimura Y. β-Galactosidase from Ginkgo biloba seeds active against β-galactose-containing N-glycans: purification and characterization. Biosci Biotechnol Biochem 2015; 79:1464-72. [DOI: 10.1080/09168451.2015.1034653] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Abstract
In this study, we purified an acidic β-galactosidase to homogeneity from Ginkgo biloba seeds (β-Gal’ase Gb-1) with approximately 270-fold purification. A molecular mass of the purified β-Gal’ase Gb-1 was estimated about 35 kDa by gel filtration and 32 kDa by SDS-PAGE under non-reducing condition, respectively. On the other hand, β-Gal’ase Gb-1 produced a single band with a molecular mass of 16 kDa by SDS-PAGE under reducing condition. The N-terminal amino acid sequences of 32 kDa and 16 kDa molecules were the same and identified as H-K-A-N-X-V-T-V-A-F-V-M-T-Q-H-, suggesting that β-Gal’ase Gb-1 may function as a homodimeric structure in vivo. When complex-type N-glycans containing β-galactosyl residues were used as substrates, β-Gal’ase Gb-1 showed substantial activity for β1-4 galactosyl residue and modest activity for β1-3 galactosyl residue with an optimum pH near 5.0. Based on these results, the involvement of β-Gal’ase Gb-1 in the degradation of plant complex-type N-glycans is discussed.
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Affiliation(s)
- Md Ziaur Rahman
- Department of Biofunctional Chemistry, Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
- Institute of Food and Radiation Biology, Atomic Energy Research Establishment, Bangladesh Atomic Energy Commission, Dhaka, Bangladesh
| | - Megumi Maeda
- Department of Biofunctional Chemistry, Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Yoshinobu Kimura
- Department of Biofunctional Chemistry, Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
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Mahn A, Angulo A, Cabañas F. Purification and characterization of broccoli (Brassica oleracea var. italica) myrosinase (β-thioglucosidase glucohydrolase). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:11666-11671. [PMID: 25390544 DOI: 10.1021/jf504957c] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Myrosinase (β-thioglucosidase glucohydrolase, EC 3.2.1.147) from broccoli (Brassica oleracea var. italica) was purified by ammonium sulfate precipitation followed by concanavalin A affinity chromatography, with an intermediate dialysis step, resulting in 88% recovery and 1318-fold purification. These are the highest values reported for the purification of any myrosinase. The subunits of broccoli myrosinase have a molecular mass of 50-55 kDa. The native molecular mass of myrosinase was 157 kDa, and accordingly, it is composed of three subunits. The maximum activity was observed at 40 °C and at pH below 5.0. Kinetic assays demonstrated that broccoli myrosinase is subjected to substrate (sinigrin) inhibition. The Michaelis-Menten model, considering substrate inhibition, gave Vmax equal to 0.246 μmol min(-1), Km equal to 0.086 mM, and K(I) equal to 0.368 mM. This is the first study about purification and characterization of broccoli myrosinase.
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Affiliation(s)
- Andrea Mahn
- Department of Chemical Engineering, University of Santiago of Chile , Avenida Libertador Bernardo O'Higgins 3363, Estación Central, Santiago 9170019, Chile
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Lemes AC, Machado JR, Brites ML, Luccio MD, Kalil SJ. Design Strategies for Integratedβ-Galactosidase Purification Processes. Chem Eng Technol 2014. [DOI: 10.1002/ceat.201300433] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Duman Y(A, Kaya E. Purification, recovery, and characterization of chick pea (Cicer arietinum) β-galactosidase in single step by three phase partitioning as a rapid and easy technique. Protein Expr Purif 2013; 91:155-60. [DOI: 10.1016/j.pep.2013.08.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 07/16/2013] [Accepted: 08/03/2013] [Indexed: 10/26/2022]
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Gerardi C, Blando F, Santino A. Purification and chemical characterisation of a cell wall-associated β-galactosidase from mature sweet cherry (Prunus avium L.) fruit. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2012; 61:123-30. [PMID: 23121861 DOI: 10.1016/j.plaphy.2012.09.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 09/21/2012] [Indexed: 05/11/2023]
Abstract
Using four different chromatographic steps, β-galactosidase was purified from the ripe fruit of sweet cherry to apparent electrophoretic homogeneity with approximately 131-fold purification. The Prunus avium β-galactosidase showed an apparent molecular mass of about 100 kDa and consisted of four different active polypeptides with pIs of about 7.9, 7.4, 6.9 and 6.4 as estimated by native IEF and β-galactosidase-activity staining. The active polypeptides were individually excised from the gel and subjected to SDS-PAGE. Each of the four native enzymes showing β-galactosidase activity was composed of two polypeptides with an estimated mass of 54 and 33 kDa. Both of these polypeptides were subjected to N-terminal amino acid sequence analysis. The 54 kDa polypeptide of sweet cherry β-galactosidase showed a 43% identity with the 44 kDa subunit of persimmon and apple β-galactosidases and the 48 kDa subunit of carambola galactosidase I. The sweet cherry β-galactosidase exhibited a strict specificity towards p-nitrophenyl β-D-galactopyranoside, a pH optimum of 4.0 and K(m) and V(max) values of 0.42 mM and 4.12 mmol min(-1) mg(-1) of protein respectively with this substrate. The enzyme was also active towards complex glycans. Taken together the results of this study prompted a role for this class of enzymes on sweet cherry fruit ripening and softening.
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Affiliation(s)
- Carmela Gerardi
- Institute of Sciences of Food Production, C.N.R. Unit of Lecce, via Monteroni, 73100 Lecce, Italy.
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Kishore D, Kayastha AM. A β-galactosidase from chick pea (Cicer arietinum) seeds: Its purification, biochemical properties and industrial applications. Food Chem 2012; 134:1113-22. [DOI: 10.1016/j.foodchem.2012.03.032] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 01/30/2012] [Accepted: 03/06/2012] [Indexed: 11/25/2022]
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Membrane processing for purification and concentration of β-glycosidases from barley (Hordeum vulgare). BIOTECHNOL BIOPROC E 2011. [DOI: 10.1007/s12257-010-0368-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Hemavathi AB, Umesh Hebbar H, Raghavarao KSMS. Reverse Micellar Extraction of β-Galactosidase from Barley (Hordeum vulgare). Appl Biochem Biotechnol 2008; 151:522-31. [DOI: 10.1007/s12010-008-8228-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Accepted: 03/25/2008] [Indexed: 10/22/2022]
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Gantulga D, Turan Y, Bevan DR, Esen A. The Arabidopsis At1g45130 and At3g52840 genes encode beta-galactosidases with activity toward cell wall polysaccharides. PHYTOCHEMISTRY 2008; 69:1661-70. [PMID: 18359051 DOI: 10.1016/j.phytochem.2008.01.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Revised: 01/15/2008] [Accepted: 01/21/2008] [Indexed: 05/21/2023]
Abstract
The Arabidopsis genes At1g45130 and At3g52840 encode the beta-galactosidase isozymes Gal-5 and Gal-2 that belong to Glycosyl Hydrolase Family 35 (GH 35). The two enzymes share 60% sequence identity with each other and 38-81% with other plant beta-galactosidases that are reported to be involved in cell wall modification. We studied organ-specific expression of the two isozymes. According to our western blot analysis using peptide-specific antibodies, Gal-5 and Gal-2 are most highly expressed in stem and rosette leaves. We show by dot-immunoblotting that Gal-5 and Gal-2 are associated with the cell wall in Arabidopsis. We also report expression of the recombinant enzymes in P. pastoris and describe their substrate specificities. Both enzymes hydrolyze the synthetic substrate para-nitrophenyl-beta-d-galactopyranoside and display optimal enzyme activity between pH 4.0 and 4.5, similar to the pH optimum reported for other well-characterized plant beta-galactosidases. Both Gal-5 and Gal-2 show a broad specificity for the aglycone moiety and a strict specificity for the glycone moiety in that they prefer galactose and its 6-deoxy analogue, fucose. Both enzymes cleave beta-(1,4) and beta-(1,3) linkages in galacto-oligosaccharides and hydrolyze the pectic fraction of Arabidopsis cell wall. These findings suggest that Gal-5 and Gal-2 could be involved in the modification of cell wall polysaccharides.
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Affiliation(s)
- Dashzeveg Gantulga
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States
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Dean GH, Zheng H, Tewari J, Huang J, Young DS, Hwang YT, Western TL, Carpita NC, McCann MC, Mansfield SD, Haughn GW. The Arabidopsis MUM2 gene encodes a beta-galactosidase required for the production of seed coat mucilage with correct hydration properties. THE PLANT CELL 2007; 19:4007-21. [PMID: 18165329 PMCID: PMC2217648 DOI: 10.1105/tpc.107.050609] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Revised: 12/10/2007] [Accepted: 12/12/2007] [Indexed: 05/17/2023]
Abstract
Seed coat development in Arabidopsis thaliana involves a complex pathway where cells of the outer integument differentiate into a highly specialized cell type after fertilization. One aspect of this developmental process involves the secretion of a large amount of pectinaceous mucilage into the apoplast. When the mature seed coat is exposed to water, this mucilage expands to break the primary cell wall and encapsulate the seed. The mucilage-modified2 (mum2) mutant is characterized by a failure to extrude mucilage on hydration, although mucilage is produced as normal during development. The defect in mum2 appears to reside in the mucilage itself, as mucilage fails to expand even when the barrier of the primary cell wall is removed. We have cloned the MUM2 gene and expressed recombinant MUM2 protein, which has beta-galactosidase activity. Biochemical analysis of the mum2 mucilage reveals alterations in pectins that are consistent with a defect in beta-galactosidase activity, and we have demonstrated that MUM2 is localized to the cell wall. We propose that MUM2 is involved in modifying mucilage to allow it to expand upon hydration, establishing a link between the galactosyl side-chain structure of pectin and its physical properties.
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Affiliation(s)
- Gillian H Dean
- Department of Botany, University of British Columbia, Vancouver, Canada V6T 1Z4
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Kestwal RM, Bhide SV. Purification of β-galactosidase from Erythrina indica: Involvement of tryptophan in active site. Biochim Biophys Acta Gen Subj 2007; 1770:1506-12. [PMID: 17761389 DOI: 10.1016/j.bbagen.2007.07.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Revised: 07/06/2007] [Accepted: 07/06/2007] [Indexed: 10/23/2022]
Abstract
beta-Galactosidase (EC: 3.2.1.23), one of the glycosidases detected in Erythrina indica seeds, was purified to 135 fold. Amongst the four major glycosidases detected beta-galactosidase was found to be least glycosylated, and was not retained by Con-A CL Seralose affinity matrix. A homogenous preparation of the enzyme was obtained by ion-exchange chromatography, followed by gel filtration. The enzyme was found to be a dimmer with a molecular weight of 74 kDa and 78 kDa, by gel filtration and SDS-PAGE, respectively. The optimum pH and optimum temperature for enzyme activity were 4.4 and 50 degrees C, respectively. The enzyme showed a K(m) value of 2.6 mM and V(max) of 3.86 U/mg for p-nitrophenyl-beta-D-galactopyranoside as substrate and was inhibited by Zn(2+) and Hg(2+). The enzyme activity was regulated by feed back inhibition as it was found to be inhibited by beta-D-galactose. Chemical modification studies revealed involvement of tryptophan and histidine for enzyme activity. Involvement of tryptophan was also supported by fluorescence studies and one tryptophan was found to be present in the active site of beta-galactosidase. Circular dichroism studies revealed 37% alpha helix, 27% beta sheet and 38% random coil in the secondary structure of the purified enzyme.
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Affiliation(s)
- Rakesh M Kestwal
- Division of Biochemistry, Department of Chemistry, University of Pune, Pune-411007, Maharashtra, India
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Agoreyo B, Golden K, Asemota H, Osagie A. Postharvest Biochemistry of the Plantain (Musa paradisiacal L.). ACTA ACUST UNITED AC 2006. [DOI: 10.3923/jbs.2007.136.144] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Minic Z, Jouanin L. Plant glycoside hydrolases involved in cell wall polysaccharide degradation. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2006; 44:435-49. [PMID: 17023165 DOI: 10.1016/j.plaphy.2006.08.001] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Indexed: 05/12/2023]
Abstract
The cell wall plays a key role in controlling the size and shape of the plant cell during plant development and in the interactions of the plant with its environment. The cell wall structure is complex and contains various components such as polysaccharides, lignin and proteins whose composition and concentration change during plant development and growth. Many studies have revealed changes in cell walls which occur during cell division, expansion, and differentiation and in response to environmental stresses; i.e. pathogens or mechanical stress. Although many proteins and enzymes are necessary for the control of cell wall organization, little information is available concerning them. An important advance was made recently concerning cell wall organization as plant enzymes that belong to the superfamily of glycoside hydrolases and transglycosidases were identified and characterized; these enzymes are involved in the degradation of cell wall polysaccharides. Glycoside hydrolases have been characterized using molecular, genetic and biochemical approaches. Many genes encoding these enzymes have been identified and functional analysis of some of them has been performed. This review summarizes our current knowledge about plant glycoside hydrolases that participate in the degradation and reorganisation of cell wall polysaccharides in plants focussing particularly on those from Arabidopsis thaliana.
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Affiliation(s)
- Z Minic
- Laboratoire de biologie cellulaire, Institut national de la recherche agronomique, route de Saint-Cyr, 78026 Versailles cedex, France
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Soh CP, Ali ZM, Lazan H. Characterisation of an alpha-galactosidase with potential relevance to ripening related texture changes. PHYTOCHEMISTRY 2006; 67:242-54. [PMID: 16325871 DOI: 10.1016/j.phytochem.2005.09.032] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Revised: 09/28/2005] [Accepted: 09/29/2005] [Indexed: 05/05/2023]
Abstract
alpha-Galactosidase (EC 3.2.1.22) from ripe papaya (Carica papaya L.) fruit was fractionated by a combination of ion exchange and gel filtration chromatography into three forms, viz., alpha-galactosidase 1, 2 and 3. The predominant isoform, alpha-gal 2, was probably a tetramer with a native molecular mass of about 170 kDa and 52 kDa-sized subunits and an estimated pI of 7.3. The subunit's N-terminal amino acid sequence shared high identity (97%) with the deduced sequence of a papaya cDNA clone encoding a putative alpha-galactosidase PAG2 as well as with an Ajuga reptans L. GGT1 clone encoding a galactan: galactan galactosyltransferase (66%). During ripening, alpha-galactosidase activity increased concomitantly with firmness loss and this increase was largely ascribed to alpha-gal 2. The protein level of alpha-gal 2 as estimated by immunoblot was low in developing fruits and generally increased with ripening. alpha-Galactosidase 2 also had the ability to markedly catalyse increased pectin solubility and depolymerisation while the polymers were still structurally attached to the cell walls mimicking, in part, the changes that occur during ripening. The close correlation between texture changes, alpha-gal 2 activity and protein levels as well as capability to modify intact cell walls suggest that the enzyme might contribute to papaya fruit softening during ripening. The purported mechanism of alpha-gal 2 action as a softening enzyme was discussed in terms of its functional capacity as a glycanase or perhaps, as a transglycosylase.
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Affiliation(s)
- Chin-Pin Soh
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
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