α-酮异己酰谷氨酰胺是维持成纤维细胞生长的合适谷氨酰胺前体吗？

Is alpha-ketoisocaproyl-glutamine a suitable glutamine precursor to sustain fibroblast growth?

作者信息

Coudray-Lucas C, Lasnier E, Renaud F, Ziegler F, Settembre P, Cynober L A, Ekindjian O G

机构信息

Inflammation and Cell Biology Laboratory, University Paris XI, Chatenay, France.

出版信息

Clin Nutr. 1999 Feb;18(1):29-33. doi: 10.1016/s0261-5614(99)80046-6.

DOI:10.1016/s0261-5614(99)80046-6

PMID:10459079

Abstract

BACKGROUND

Glutamine is considered an essential nutrient for cellular growth.

AIM

To test the suitability of alpha-ketoisocaproyl-Gln (Kic-Gln) as a new glutamine (Gln) precursor to sustain human fibroblast growth.

METHODS

[3H] thymidine uptake into cellular DNA of human fibroblasts. Extracellular and intracellular amino acid patterns were determined with peptides and acylated compounds.

RESULTS

L-alanyl-L-glutamine (used here as a recognized Gln precursor) promoted DNA synthesis, while N-acetyl-L-glutamine (used here as a negative control since it is known to be a poor Gln precursor) and alpha-ketoisocaproyl-glutamine had no effect. Alanyl-glutamine progressively gave rise to free glutamine in the growth medium. In contrast, glutamine supplied in acylated form was poorly available and did not appear in free form in the medium. In addition, only alanyl-glutamine increased intracellular glutamine and glutamate levels. In contrast, Kic-Gln was able to sustain net protein synthesis as judged by total protein content and reduced intracellular levels of most essential amino acids.

CONCLUSION

Kic-Gln appears to be a poor extra-cellular precursor of Gln to sustain cell growth.

摘要

背景

谷氨酰胺被认为是细胞生长的必需营养素。

目的

测试α-酮异己酰谷氨酰胺（Kic-Gln）作为一种新的谷氨酰胺（Gln）前体以维持人成纤维细胞生长的适用性。

方法

通过[3H]胸苷掺入人成纤维细胞的细胞DNA中。用肽和酰化化合物测定细胞外和细胞内氨基酸模式。

结果

L-丙氨酰-L-谷氨酰胺（在此用作公认的Gln前体）促进DNA合成，而N-乙酰-L-谷氨酰胺（在此用作阴性对照，因为已知它是一种较差的Gln前体）和α-酮异己酰谷氨酰胺没有作用。丙氨酰谷氨酰胺在生长培养基中逐渐产生游离谷氨酰胺。相反，以酰化形式提供的谷氨酰胺利用率低，并且在培养基中不会以游离形式出现。此外，只有丙氨酰谷氨酰胺增加细胞内谷氨酰胺和谷氨酸水平。相比之下，根据总蛋白含量判断，Kic-Gln能够维持净蛋白合成，并降低大多数必需氨基酸的细胞内水平。