ACCUMULATION OF 3-(N-MORPHOLINO)PROPANESULFONATE BY OSMOTICALLY STRESSED ESCHERICHIA-COLI K-12
ACCUMULATION OF 3-(N-MORPHOLINO)PROPANESULFONATE BY OSMOTICALLY STRESSED ESCHERICHIA-COLI K-12
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DOI：
10.1128/jb.171.7.3597-3602.1989
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发表时间：
1989-07-01
影响因子：
3.2
通讯作者：
LEWIS, BA
中科院分区：
文献类型：
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作者：
CAYLEY, S;RECORD, MT;LEWIS, BA
我们发现，外源性morpholinopropanesulfonate（MOPS）是浓缩约五倍的大肠杆菌K-12（菌株MG 1665）的细胞质的自由体积时，在两种不同的培养基中含有40 mM MOPS的高渗透压（1.1 OsM）生长。MOPS不被E.在低渗透压MOPS缓冲培养基或含有渗透保护剂甘氨酸甜菜碱的1.1OsM MOPS缓冲培养基中生长的大肠杆菌中，鼠伤寒沙门氏菌LT 2在任何检测条件下都不积累MOPS。我们推测，MOPS积累的E。coliK-12中的蛋白质转运不是由于被动平衡而是由于转运，可能涉及到一种在S.鼠伤寒。谷氨酸和MOPS是我们在E. coli K-12在MOPS缓冲培养基中生长。正电荷的增加，伴随着在稳态量的K+细胞从低到高的外部渗透压的增加似乎是由腐胺，谷氨酸，和MOPS的量的变化补偿。MOPS不是一种植物保护剂，因为它的积累不会增加细胞的生长速率。
We found that exogenous morpholinopropanesulfonate (MOPS) is concentrated approximately fivefold in the free volume of the cytoplasm of Escherichia coli K-12 (strain MG1665) when grown at high osmolarity (1.1 OsM) in two different media containing 40 mM MOPS. MOPS was not accumulated by E. coli grown in low-osmolarity MOPS-buffered medium or in 1.1 OsM MOPS-buffered medium containing the osmorprotectant glycine betaine, Salmonella typhimurium LT2 did not accumulate MOPS under any condition examined. We infer that accumulation of MOPS by E. coli K-12 is not due to passive equilibration but rather to transport, possibly involving an as yet uncharacterized porter not present in S. typhimurium. Glutamate and MOPS were the only anionic osmolytes we observed by 13C nuclear magnetic resonance in E. coli K-12 grown in MOPS-buffered medium. The increase in positive charge accompanying the increase in the steady-state amount of K+ in cells shifted from low to high external osmolarity appeared to be compensated for by changes in the amounts of putrescine, glutamate, and MOPS. MOPS is not an osmoprotectant, because its accumulation did not increase cell growth rate.