Allosteric Regulation of the Partitioning of Glucose-1-phosphate Between Glycogen and Trehalose Biosynthesis in Mycobacterium tuberculosis

ASENCIÓN DIEZ, MD; DEMONTE, AM; SYSON, K; ARIAS, DG; GORELIK, A; GUERRERO, SA; BORNEMANN, S; IGLESIAS, AA

BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 1850 p. 13 - 21

0304-4165

Background: Mycobacterium tuberculosis is a pathogenic prokaryote adapted to survive in hostile environments. In this organism and other Gram-positive actinobacteria, the metabolic pathways of glycogen and trehalose are interconnected.Results: In thisworkwe showthe production, purification and characterization of recombinant enzymes involved in the partitioning of glucose-1-phosphate between glycogen and trehalose in M. tuberculosis H37Rv, namely: ADP-glucose pyrophosphorylase, glycogen synthase, UDP-glucose pyrophosphorylase and trehalose-6-phosphate synthase. The substrate specificity, kinetic parameters and allosteric regulation of each enzymewere determined. ADP-glucose pyrophosphorylase was highly specific for ADP-glucose while trehalose-6-phosphate synthase used not only ADP-glucose but also UDP-glucose, albeit to a lesser extent. ADP-glucose pyrophosphorylase was allosterically activated primarily by phosphoenolpyruvate and glucose-6-phosphate, while the activity of trehalose-6-phosphate synthase was increased up to 2-fold by fructose-6-phosphate. None of the other two enzymes tested exhibited allosteric regulation. Conclusions: Results give information about how the glucose-1-phosphate/ADP-glucose node is controlled after kinetic and regulatory properties of key enzymes for mycobacteria metabolism.General significance: This work increases our understanding of oligo and polysaccharides metabolism in M. tuberculosis and reinforces the importance of the interconnection between glycogen and trehalose biosynthesis in this human pathogen.