脂肪组织中2-氧代戊二酸的线粒体内还原性羧化作用及其对脂肪酸合成的贡献。

Intramitochondrial reductive carboxylation of 2-oxoglutarate in adipose tissue and its contribution to fatty acid synthesis.

作者信息

Lenartowicz E, Savina M V

出版信息

Int J Biochem. 1984;16(12):1223-9. doi: 10.1016/0020-711x(84)90220-9.

Abstract

The reductive carboxylation of 2-oxoglutarate was found to proceed in mitochondria of rat epididymal fat pads and rabbit perirenal adipose tissue at a rate similar to that in liver mitochondria. In rat fat pads the incorporation of 14C from [5-14C]2-oxoglutarate into fatty acids via the carboxylation was suppressed by butylmalonate by 30%. 2-Oxoglutarate and glutamate stimulated the incorporation into fatty acids of 14C from [2-14C]acetate in rat fat pads with the simultaneous reduction of tissue NADP. These effects persisted after inhibition of succinate dehydrogenase by malonate. It is concluded that in adipose tissue 2-oxoglutarate carboxylation proceeds in both the cytoplasm and mitochondria. Therefore, it can supply carbon atoms as well as NADPH for fatty acid synthesis.

摘要

已发现2-氧代戊二酸的还原性羧化作用在大鼠附睾脂肪垫和兔肾周脂肪组织的线粒体中以与肝线粒体相似的速率进行。在大鼠脂肪垫中，丁基丙二酸将[5-¹⁴C]2-氧代戊二酸中的¹⁴C通过羧化作用掺入脂肪酸的过程抑制了30%。2-氧代戊二酸和谷氨酸刺激了大鼠脂肪垫中[2-¹⁴C]乙酸盐的¹⁴C掺入脂肪酸，同时组织中的NADP减少。在用丙二酸抑制琥珀酸脱氢酶后，这些作用仍然存在。得出的结论是，在脂肪组织中，2-氧代戊二酸羧化作用在细胞质和线粒体中均会发生。因此，它可为脂肪酸合成提供碳原子以及NADPH。