Biochemical characterization of human gluconokinase and the proposed metabolic impact of gluconic acid as determined by constraint based metabolic network analysis

Rohatgi, N; Nielsen, TK; Bjørn, SP; Axelsson, I; Paglia, G; Voldborg, BG; Palsson, BO; Rolfsson, Ó

HERO ID

4825338

Reference Type

Journal Article

Year

2014

Language

English

PMID

24896608

HERO ID 4825338
In Press No
Year 2014
Title Biochemical characterization of human gluconokinase and the proposed metabolic impact of gluconic acid as determined by constraint based metabolic network analysis
Authors Rohatgi, N; Nielsen, TK; Bjørn, SP; Axelsson, I; Paglia, G; Voldborg, BG; Palsson, BO; Rolfsson, Ó
Journal PLoS ONE
Volume 9
Issue 6
Page Numbers e98760
Abstract The metabolism of gluconate is well characterized in prokaryotes where it is known to be degraded following phosphorylation by gluconokinase. Less is known of gluconate metabolism in humans. Human gluconokinase activity was recently identified proposing questions about the metabolic role of gluconate in humans. Here we report the recombinant expression, purification and biochemical characterization of isoform I of human gluconokinase alongside substrate specificity and kinetic assays of the enzyme catalyzed reaction. The enzyme, shown to be a dimer, had ATP dependent phosphorylation activity and strict specificity towards gluconate out of 122 substrates tested. In order to evaluate the metabolic impact of gluconate in humans we modeled gluconate metabolism using steady state metabolic network analysis. The results indicate that significant metabolic flux changes in anabolic pathways linked to the hexose monophosphate shunt (HMS) are induced through a small increase in gluconate concentration. We argue that the enzyme takes part in a context specific carbon flux route into the HMS that, in humans, remains incompletely explored. Apart from the biochemical description of human gluconokinase, the results highlight that little is known of the mechanism of gluconate metabolism in humans despite its widespread use in medicine and consumer products.
Doi 10.1371/journal.pone.0098760
Pmid 24896608
Wosid WOS:000338430700072
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English