Characterisation of a soil MINPP phytase with remarkable long-term stability and activity from Acinetobacter sp.
Characterisation of a soil MINPP phytase with remarkable long-term stability and activity from Acinetobacter sp.
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具有显着的长期稳定性和活性的土壤MINPP植物酶的表征。
DOI：
10.1371/journal.pone.0272015
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发表时间：
2022
期刊：
影响因子：
3.7
通讯作者：
Brearley, Charles A.
中科院分区：
文献类型：
--
作者：
Rix, Gregory D.;Sprigg, Colleen;Whitfield, Hayley;Hemmings, Andrew M.;Todd, Jonathan D.;Brearley, Charles A.
采用系统发育分析、同源性建模和生物化学方法对一株革兰氏阴性土壤细菌植酸酶进行了研究。不动杆菌AC 1 -2植酸酶属于组氨酸（酸）植酸酶的进化枝2，属于多肌醇多磷酸磷酸酶（MINPP）亚类。该酶在室温和4°C下的溶液中都非常稳定，在755天内保持接近100%的活性。它显示出从2-8.5的宽pH活性曲线，在3、4.5-5和6处具有最大值。该酶表现出米氏动力学和底物抑制（Vmax、Km和Ki分别为228 U/mg、0.65 mM和2.23 mM）。同源性建模使用的晶体结构的同源MINPP从人类肠道寄生菌表明存在一个潜在的稳定多肽环（一个U-环）跨越的活性位点。通过利用拟南芥肌醇三/四磷酸激酶1对五磷酸肌醇的对映体特异性，我们表明AC 1 -2 MINPP具有D 6-植酸酶活性，这允许对InsP 6底物的活性位点特异性口袋进行建模。虽然植酸酶基因转录在丰富的媒体是不变的，它是抑制在基本培养基与植酸和正磷酸盐作为磷酸盐来源。本研究的结果表明，AC 1 -2 MINPP具有生物技术应用相关的理想属性。
Phylogenetic analysis, homology modelling and biochemical methods have been employed to characterize a phytase from a Gram-negative soil bacterium. Acinetobacter sp. AC1-2 phytase belongs to clade 2 of the histidine (acid) phytases, to the Multiple Inositol Polyphosphate Phosphatase (MINPP) subclass. The enzyme was extraordinarily stable in solution both at room temperature and 4°C, retaining near 100% activity over 755 days. It showed a broad pH activity profile from 2–8.5 with maxima at 3, 4.5–5 and 6. The enzyme showed Michaelis-Menten kinetics and substrate inhibition (Vmax, Km, and Ki, 228 U/mg, 0.65 mM and 2.23 mM, respectively). Homology modelling using the crystal structure of a homologous MINPP from a human gut commensal bacterium indicated the presence of a potentially stabilising polypeptide loop (a U-loop) straddling the active site. By employ of the enantiospecificity of Arabidopsis inositol tris/tetrakisphosphate kinase 1 for inositol pentakisphosphates, we show AC1-2 MINPP to possess D6-phytase activity, which allowed modelling of active site specificity pockets for InsP6 substrate. While phytase gene transcription was unaltered in rich media, it was repressed in minimal media with phytic acid and orthophosphate as phosphate sources. The results of this study reveal AC1-2 MINPP to possess desirable attributes relevant to biotechnological use.
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影响因子：
9.5
作者：
Katoh K;Rozewicki J;Yamada KD
通讯作者：
Yamada KD
DOI：
10.1016/j.ijfoodmicro.2009.07.015
发表时间：
2009-09-30
影响因子：
5.4
作者：
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影响因子：
1.9
作者：
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通讯作者：
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影响因子：
4.6
作者：
Farias, Nathalya;Almeida, Isabela;Meneses, Carlos
通讯作者：
Meneses, Carlos
影响因子：
2.9
作者：
Dokuzparmak, Emre;Sirin, Yakup;Ertunga, Nagihan Saglam
通讯作者：
Ertunga, Nagihan Saglam