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Influence of Calcium Ions on the Thermal Characteristics of α-amylase from Thermophilic Anoxybacillus sp. GXS-BL
BACKGROUND: α-Amylases are starch-degrading enzymes and used widely, the study on thermostability of α-amylase is a central requirement for its application in life science and biotech-nology. OBJECTIVE: In this article, our motivation is to study how the effect of Ca2+ ions on the structure and ther...
Autores principales: | , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Bentham Science Publishers
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6416487/ https://www.ncbi.nlm.nih.gov/pubmed/30652633 http://dx.doi.org/10.2174/0929866526666190116162958 |
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author | Liao, Si-Ming Liang, Ge Zhu, Jing Lu, Bo Peng, Li-Xin Wang, Qing-Yan Wei, Yu-Tuo Zhou, Guo-Ping Huang, Ri-Bo |
author_facet | Liao, Si-Ming Liang, Ge Zhu, Jing Lu, Bo Peng, Li-Xin Wang, Qing-Yan Wei, Yu-Tuo Zhou, Guo-Ping Huang, Ri-Bo |
author_sort | Liao, Si-Ming |
collection | PubMed |
description | BACKGROUND: α-Amylases are starch-degrading enzymes and used widely, the study on thermostability of α-amylase is a central requirement for its application in life science and biotech-nology. OBJECTIVE: In this article, our motivation is to study how the effect of Ca2+ ions on the structure and thermal characterization of α-amylase (AGXA) from thermophilic Anoxybacillus sp.GXS-BL. METHODS: α-Amylase activity was assayed with soluble starch as the substrate, and the amount of sugar released was determined by DNS method. For AGXA with calcium ions and without calcium ions, optimum temperature (Topt), half-inactivation temperature (T50) and thermal inactivation (half-life, t1/2) was evaluated. The thermal denaturation of the enzymes was determined by DSC and CD methods. 3D structure of AGXA was homology modeled with α-amylase (5A2A) as the template. RESULTS: With calcium ions, the values of Topt, T50, t1/2, Tm and ΔH in AGXA were significantly high-er than those of AGXA without calcium ions, showing calcium ions had stabilizing effects on α-amylase structure with the increased temperature. Based on DSC measurements AGXA underwent thermal denaturation by adopting two-state irreversible unfolding processes. Based on the CD spectra, AGXA without calcium ions exhibited two transition states upon unfolding, including α-helical contents increasing, and the transition from α-helices to β-sheet structures, which was obviously dif-ferent in AGXA with Ca2+ ions, and up to 4 Ca2+ ions were located on the inter-domain or intra-domain regions according to the modeling structure. CONCLUSION: These results reveal that Ca(2+) ions have pronounced influences on the thermostability of AGXA structure. |
format | Online Article Text |
id | pubmed-6416487 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Bentham Science Publishers |
record_format | MEDLINE/PubMed |
spelling | pubmed-64164872019-04-10 Influence of Calcium Ions on the Thermal Characteristics of α-amylase from Thermophilic Anoxybacillus sp. GXS-BL Liao, Si-Ming Liang, Ge Zhu, Jing Lu, Bo Peng, Li-Xin Wang, Qing-Yan Wei, Yu-Tuo Zhou, Guo-Ping Huang, Ri-Bo Protein Pept Lett Article BACKGROUND: α-Amylases are starch-degrading enzymes and used widely, the study on thermostability of α-amylase is a central requirement for its application in life science and biotech-nology. OBJECTIVE: In this article, our motivation is to study how the effect of Ca2+ ions on the structure and thermal characterization of α-amylase (AGXA) from thermophilic Anoxybacillus sp.GXS-BL. METHODS: α-Amylase activity was assayed with soluble starch as the substrate, and the amount of sugar released was determined by DNS method. For AGXA with calcium ions and without calcium ions, optimum temperature (Topt), half-inactivation temperature (T50) and thermal inactivation (half-life, t1/2) was evaluated. The thermal denaturation of the enzymes was determined by DSC and CD methods. 3D structure of AGXA was homology modeled with α-amylase (5A2A) as the template. RESULTS: With calcium ions, the values of Topt, T50, t1/2, Tm and ΔH in AGXA were significantly high-er than those of AGXA without calcium ions, showing calcium ions had stabilizing effects on α-amylase structure with the increased temperature. Based on DSC measurements AGXA underwent thermal denaturation by adopting two-state irreversible unfolding processes. Based on the CD spectra, AGXA without calcium ions exhibited two transition states upon unfolding, including α-helical contents increasing, and the transition from α-helices to β-sheet structures, which was obviously dif-ferent in AGXA with Ca2+ ions, and up to 4 Ca2+ ions were located on the inter-domain or intra-domain regions according to the modeling structure. CONCLUSION: These results reveal that Ca(2+) ions have pronounced influences on the thermostability of AGXA structure. Bentham Science Publishers 2019-02 2019-02 /pmc/articles/PMC6416487/ /pubmed/30652633 http://dx.doi.org/10.2174/0929866526666190116162958 Text en © 2019 Bentham Science Publishers https://creativecommons.org/licenses/by-nc/4.0/legalcode This is an open access article licensed under the terms of the Creative Commons Attribution-Non-Commercial 4.0 International Public License (CC BY-NC 4.0) (https://creativecommons.org/licenses/by-nc/4.0/legalcode), which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited. |
spellingShingle | Article Liao, Si-Ming Liang, Ge Zhu, Jing Lu, Bo Peng, Li-Xin Wang, Qing-Yan Wei, Yu-Tuo Zhou, Guo-Ping Huang, Ri-Bo Influence of Calcium Ions on the Thermal Characteristics of α-amylase from Thermophilic Anoxybacillus sp. GXS-BL |
title | Influence of Calcium Ions on the Thermal Characteristics of α-amylase from Thermophilic Anoxybacillus sp. GXS-BL |
title_full | Influence of Calcium Ions on the Thermal Characteristics of α-amylase from Thermophilic Anoxybacillus sp. GXS-BL |
title_fullStr | Influence of Calcium Ions on the Thermal Characteristics of α-amylase from Thermophilic Anoxybacillus sp. GXS-BL |
title_full_unstemmed | Influence of Calcium Ions on the Thermal Characteristics of α-amylase from Thermophilic Anoxybacillus sp. GXS-BL |
title_short | Influence of Calcium Ions on the Thermal Characteristics of α-amylase from Thermophilic Anoxybacillus sp. GXS-BL |
title_sort | influence of calcium ions on the thermal characteristics of α-amylase from thermophilic anoxybacillus sp. gxs-bl |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6416487/ https://www.ncbi.nlm.nih.gov/pubmed/30652633 http://dx.doi.org/10.2174/0929866526666190116162958 |
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