HYDROLYSIS OF PROLINE DIPEPTIDES COMPLETELY FULFILLS THE PROLINE REQUIREMENT IN A PROLINE-AUXOTROPHIC CHINESE-HAMSTER OVARY CELL-LINE
HYDROLYSIS OF PROLINE DIPEPTIDES COMPLETELY FULFILLS THE PROLINE REQUIREMENT IN A PROLINE-AUXOTROPHIC CHINESE-HAMSTER OVARY CELL-LINE
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DOI：
10.1093/jn/123.5.909
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发表时间：
1993-05-01
影响因子：
4.2
通讯作者：
PHANG, JM
中科院分区：
文献类型：
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作者：
EMMERSON, KS;PHANG, JM
含脯氨酸和羟脯氨酸的寡肽在蛋白质营养中可能是重要的，因为肠水解酶不能识别它们的亚氨基键。外周组织具有胞质酶脯氨酰二肽酶，其切割含有C-末端脯氨酸（X-Pro）或羟脯氨酸的二肽。二肽在细胞内代谢中的作用尚不确定。本研究检查了X-Pro向脯氨酸营养缺陷型细胞系CHO-K1提供脯氨酸的能力。氨酰基脯氨酸二肽酶对外源性Gly-Pro（最丰富的二肽消化产物）的作用提供了充足的脯氨酸，以剂量依赖性方式支持CHO-K1细胞的正常细胞生长。通过向CHO-K1细胞添加Gly-Pro产生的生长曲线与由于脯氨酸产生的生长曲线相似。另外两种结构上不相关的X-Pro也支持Gly-Pro的生长。Gly-Hyp对生长完全无效。X-Pro维持脯氨酸营养缺陷型细胞系的培养的能力在阐明这些二肽的细胞内营养和生理功能方面可能是重要的。
Proline- and hydroxyproline-containing oligopeptides may be important in protein nutrition because intestinal hydrolases are incapable of recognizing their imido bonds. Peripheral tissues have a cytosolic enzyme prolidase that cleaves dipeptides containing C-terminal proline (X-Pro) or hydroxyproline. The role of dipeptides in intracellular metabolism is uncertain. This study examined the ability of X-Pro to provide proline to the proline-auxotrophic cell line, CHO-K1. The action of prolidase on exogenously supplied Gly-Pro, the most abundant dipeptide product of digestion, provided adequate proline to support normal cell growth of CHO-K1 cells in a dose-dependent manner. The growth curve generated by addition of Gly-Pro to CHO-K1 cells was similar to that due to proline. Two other structurally unrelated X-Pro also supported growth indistinguishably from Gly-Pro. Gly-Hyp was completely ineffective for growth. The ability of X-Pro to sustain cultures of a proline-auxotrophic cell line may be important in elucidating intracellular nutritional and physiological functions for those dipeptides.