Because it can’t be synthesized in the body, as an essential amino acid, tryptophan (TRP) are indispensible in the diets of monogastric animals like humans, pigs, dogs and preweaning ruminants such as calves and lambs. Like other amino acids such as homocysteine and cysteine, TRP can form a non-covalent bond with serum albumin.
Tryptophan plays a significant role in growth, development, and health of animals and humans. In the past decades, tryptophan is widely studied as an essential amino acid of protein synthesis in mammalian. However, there are increasing evidence show that besides its primary role serving as a building block in protein biosynthesis, tryptophan and its metabolites is also the key nutrient essential for regulating nervous system, reproduction system, immune responses and anti-stress responses. What’s more, tryptophan may affect whole-body homeostasis in organisms by modulating gene expression and nutrient metabolism.
Tryptophan is special because it contains an indole nucleus and can be metabolized through different important biochemical pathways to a number of specific products in human. The diet and intracellular protein degradation are the two sources contributing to the free TRP in the body. They each contribute to about 1/3 and 2/3 of the TRP’s whole-body pool. However, since animal cells can’t synthesize the TRP, the ultimate source of tryptophan in the body is from diet. There are three metabolism pathways for tryptophan in the body. The first pathway is that TRP can be hydroxylated and decarboxylated into serotonin and 5-hydroxyindoleacetic acid involved in neurodevelopment. The second pathway is that the deamination and decarboxylation of TRP yields indoleacetic acid. The third pathway is that through the formation of kunurenine, TRP can be degraded into niacin, kynurenic acid, picolinic acid and xanthurenic acid, which contributing to the formation of pyruvate and acetyl-CoA. Niacin is essential component of NAD and NADP, which are coenzymes for many oxidoreductase enzymes taking part in the metabolism of nutrients. Because it can activate N-methyl-D-aspartic acid (NMDA) receptor subtypes, generate free radicals independently of receptor-mediated mechanisms and its significant actionon NR2A and NR2B, quinolinic acid acts as an agonist in the brain and the peripheral nervous system. Quinolinic acid may further converts to nicotinamide or nicotinic acid. In healthy adult, more than 95% of the ingested TRP is metabolized mainly in the liver through the kynurenine (KYN) pathway. That’s because the crucial enzyme for the first and rate-controlling step in kynurenine (KYN) pathway, either the ubiquitous indoleamine 2, 3-dioxygenase (IDO) or TRP 2, 3-dioxygenase (TDO) primarily exist in the liver.
Tryptophan (TRP) metabolites impairments are associated with the pathology several neurological and inflammatory diseases such as cerebral palsy, autism and Alzheimer disease. Therefore, the increasing interest in tryptophan (TRP) metabolism in research filed and industrial field demands powerful profiling analytical platform enabling simultaneous quantification of TRP and its major metabolites. To measure TRP metabolite sensitively and accurately with a single method, Creative Proteomics has established HPLC-MS/MS method for quantification of TRP and its major metabolites.
Tryptophan Metabolites Quantified in this Service
With integrated set of separation, characterization, identification and quantification systems featured with excellent robustness & reproducibility, high and ultra-sensitivity, Creative Proteomics provides reliable, rapid and cost-effective tryptophan metabolites targeted metabolomics services.