Hirshfield I N, Price M B
J Bacteriol. 1975 Jun;122(3):966-75. doi: 10.1128/jb.122.3.966-975.1975.
Studies on the utilization of leucine peptide amides as a source of leucine for a leucine auxotroph showed that in general compounds with the structure leu-chi amide (where chi is any amide) are utilized as well as the free peptide, but that compounds with the structure chi-leu amide (where chi is not leucine) are used less effectively than the free peptide. Growth and enzymological experiments indicated that the lower capacity of Escherichia coli to utilize amides of the structure chi-leu amide is not a result of poor transport of these compounds, but rather the inability to rapidly liberate leucine from the amide when it is supplied to the cell in the form of a peptide. Competition studies indicated that the peptide amides enter the cell via the oligopeptide permease system.
关于利用亮氨酸肽酰胺作为亮氨酸营养缺陷型菌株的亮氨酸来源的研究表明，一般来说，具有亮氨酸-χ酰胺结构（其中χ为任何酰胺）的化合物与游离肽一样能被利用，但具有χ-亮氨酸酰胺结构（其中χ不是亮氨酸）的化合物比游离肽的利用效率低。生长和酶学实验表明，大肠杆菌利用χ-亮氨酸酰胺结构酰胺的能力较低，不是这些化合物转运不良的结果，而是当以肽的形式提供给细胞时，无法从酰胺中快速释放亮氨酸。竞争研究表明，肽酰胺通过寡肽通透酶系统进入细胞。
