L-高丝氨酸对结核分枝杆菌生长的影响。
Effect of l-Homoserine on the Growth of Mycobacterium tuberculosis.
机构信息
Microbiology Division, U.S. Army Medical Research and Nutrition Laboratory, Fitzsimons General Hospital, Denver, Colorado 80240.
出版信息
Infect Immun. 1971 Feb;3(2):328-32. doi: 10.1128/iai.3.2.328-332.1971.
l-Homoserine was observed to inhibit the growth of Mycobacterium tuberculosis. In the metabolism of M. tuberculosis, l-homoserine was found to be a precursor of threonine, isoleucine, and methionine. l-Homoserine-inhibited cells contained elevated levels of the enzyme acetohydroxy acid synthetase. In addition, washed cell suspensions of M. tuberculosis formed significant amounts of alpha-amino-n-butyric acid from supplements of l-homoserine. dl-Alpha-amino-n-butyric acid proved to be much more inhibitory for growth than l-homoserine. Growth antagonism by l-homoserine was reversed by l-lysine, l-threonine, and combinations of l-leucine with l-valine. At the cellular level, these amino acids reduced the amount of acetohydroxy acid synthetase in cells grown with l-homoserine and competed with dl-homoserine-4-(14)C for entrance into the extractable cell pool. l-Isoleucine also antagonized the conversion of l-homoserine to alpha-amino-n-butyric acid. Available data indicated that the effect of l-homoserine was related to its conversion to alpha-amino-n-butyric acid which subsequently inhibited growth.
L-高丝氨酸被发现能够抑制结核分枝杆菌的生长。在结核分枝杆菌的代谢过程中，L-高丝氨酸被发现是苏氨酸、异亮氨酸和蛋氨酸的前体。L-高丝氨酸抑制的细胞中含有高水平的乙酰羟酸合酶。此外，从 L-高丝氨酸的补充物中，结核分枝杆菌的洗涤细胞悬浮液形成了大量的α-氨基-n-丁酸。DL-α-氨基-n-丁酸对生长的抑制作用比 L-高丝氨酸强得多。L-高丝氨酸的生长拮抗作用可以通过 L-赖氨酸、L-苏氨酸以及 L-亮氨酸与 L-缬氨酸的组合来逆转。在细胞水平上，这些氨基酸降低了在 L-高丝氨酸中生长的细胞中乙酰羟酸合酶的含量，并与 DL-高丝氨酸-4-(14)C 竞争进入可提取的细胞池。L-异亮氨酸也拮抗了 L-高丝氨酸向α-氨基-n-丁酸的转化。现有数据表明，L-高丝氨酸的作用与其转化为α-氨基-n-丁酸有关，后者随后抑制了生长。
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