Positional stable isotope tracer analysis reveals carbon routes during ammonia metabolism of Aedes aegypti mosquitoes [Research]

In this study, we used low- and high-resolution liquid chromatography-mass spectrometry (LC/MS) techniques to investigate the role of glucose during ammonia detoxification. Mosquitoes were fed a blood meal supplemented with [1,2-13C2]glucose, and downstream metabolites were measured for 24 h. Quantification of [13C] amino acids in the entire mosquito body was conducted without sample derivatization using selected reaction monitoring of mass transitions that are indicative of the structural position of [13C] atom incorporation. Identification of unlabeled and [13C] isotopologs of 43 compounds, including amino acids, amino acid derivatives, and organic acids, was performed by high-resolution LC/MS techniques. Blood-fed mosquitoes synthesized [13C] metabolites in mainly 2 carbon positions from [1,2-13C2]glucose. [13C2]Ala and [13C2]Pro were the most abundant and rapidly labeled amino acids synthesized. Additional [13C] amino acids, [13C] amino acid derivatives, and [13C] organic acids in 1 or 2 carbon positions were also identified. Two kinetic routes were proposed based on the incorporation of a [13C] atom at position 1 in specific amino acids. Our findings provide evidence that glucose is used for ammonia detoxification and [13C] uric acid synthesis through multiple metabolic pathways, uncovering a metabolic link at the carbon atomic level in ammonia metabolism of A. aegypti.—Horvath, T. D., Dagan, S., Lorenzi, P. L., Hawke, D. H., Scaraffia, P. Y. Positional stable isot...

Source: FASEB Journal - January 2, 2018 Category: Biology Authors: Horvath, T. D., Dagan, S., Lorenzi, P. L., Hawke, D. H., Scaraffia, P. Y. Tags: Research Source Type: research