Proteomic analysis of curdlan-producing Agrobacterium sp in response to pH downshift
Proteomic analysis of curdlan-producing Agrobacterium sp in response to pH downshift
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DOI：
10.1016/j.jbiotec.2008.08.010
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发表时间：
2008-11-25
影响因子：
4.1
通讯作者：
Lee, Jung-Heon
中科院分区：
文献类型：
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作者：
Jin, Li-Hua;Um, Hyun-Ju;Lee, Jung-Heon
在农杆菌ATCC 31750的分批培养过程中，使用二维电泳和基质辅助激光解吸电离飞行时间质谱法进行蛋白质组分析，以响应pH从7.0下调至5.5。当指数生长的农杆菌培养物的pH降低到pH 5.5时，与控制在pH 7.0的分批培养物相比，27种细胞内蛋白质的合成水平在延长的时间段内显示出显著的水平变化。特别是，β-1，3-葡聚糖合酶催化亚基、UTP-葡萄糖-1-磷酸尿苷酰转移酶和磷酸葡萄糖变位酶（它们是可得兰生物合成途径中的关键代谢酶）的细胞内蛋白水平在低pH培养物中高出10倍、3倍和17倍以上。从另一方面来说。乳清酸核苷5-磷酸脱羧酶（OMP向UMP的转化）的水平在pH降低后显著上调。UMP的积累可以将代谢流导向UTP的生物合成途径，UTP是UDP-葡萄糖的关键代谢前体。因此，可能的是，在pH下调培养期间细胞代谢酶的增加可以增强关键前体如UTP-和UDP-葡萄糖的生物合成的代谢通量，从而导致可得然胶生物合成的增加。(C)2008 Elsevier B. V.保留所有权利。
During batch cultivation of Agrobacterium sp. ATCC 31750, proteome analysis in response to a pH downshift from 7.0 to 5.5 was carried out using two-dimensional electrophoresis and matrix-assisted laser desorption-ionization-time of flight mass spectrometry. When the pH of the exponentially growing Agrobacterium sp. culture was downshifted to pH 5.5, the synthesis level of 27 intracellular proteins showed significant changes in level over a prolonged period of time compared with the batch culture controlled at pH 7.0. In particular, the intracellular protein level of the beta-1,3-glucan synthase catalytic subunit, UTP-glucose-1-phosphate uridylyltransferase, and phosphoglucomutase, which are key metabolic enzymes in the curdlan biosynthesis pathway, were more than 10-, 3- and 17-times higher in the low pH culture. On the other hand. the level of orotidine5-phosphate decarboxylase (conversion of OMP to UMP) was significantly up-regulated after pH downshift. The accumulation of UMP may direct the metabolic flow towards the biosynthetic route of UTP, which is a key metabolic precursor for UDP-glucose. Therefore, it is possible that increase of cellular metabolic enzymes during pH downshift culture can enhance the metabolic flux of the biosynthesis of key precursor, such as UTP- and UDP-glucose, resulting in an increase in curdlan biosynthesis. (C) 2008 Elsevier B.V. All rights reserved.