IDO metabolic pathway

Overview of the IDO metabolic pathway. Approximately 95% of L-tryptophan (Trp) is catabolized into kynurenine (Kyn) through three rate-limiting enzymes: tryptophan 2,3-dioxygenase (TDO) in the liver and indoleamine 2, 3-dioxygenase 1/2 (IDO1/2) in peripheral tissues. Kyn is converted to 3-hydroxykynurenine (3-HK) by kynurenine 3-monooxygenase (KMO), to anthranilic acid (AA) by kynureninase (KYNase), or to kynurenic acid (KYNA) by kynurenine aminotransferase (KAT). Next, catalyzed by KYNase, 3-HK is converted to 3-hydroxyanthranilic acid (3-HAA), which is further converted to quinolinic acid (QA), picolinic acid, nicotinamide adenine dinucleotide (NAD+), and other molecules. Starting point: https://pfocr.wikipathways.org/figures/PMC6090955__13045_2018_644_Fig1_HTML.html

IDO代谢途径概述。约95%的L-色氨酸（Trp）通过三个限速酶在肝脏中的色氨酸2,3-双加氧酶（TDO）和周围组织中的吲哚胺2,3-双加氧酶1/2（IDO1/2）分解为犬尿氨酸（Kyn）。犬尿氨酸通过犬尿氨酸3-单加氧酶（KMO）转化为3-羟基犬尿氨酸（3-HK），通过犬尿氨酸酶（KYNase）转化为抗坏血酸（AA），或通过犬尿氨酸转氨酶（KAT）转化为犬尿氨酸酸（KYNA）。随后，在KYNase的催化下，3-HK转化为3-羟基抗坏血酸（3-HAA），进一步转化为喹啉酸（QA）、吡啶酸、烟酰胺腺嘌呤二核苷酸（NAD+）以及其他分子。起始点：https://pfocr.wikipathways.org/figures/PMC6090955__13045_2018_644_Fig1_HTML.html