caa a22 4500 463185846 CHVBK 20180406164852.0 cr unu---uuuuu 170326e20070501xx s 000 0 eng 10.1007/s00726-006-0424-9 doi (NATIONALLICENCE)springer-10.1007/s00726-006-0424-9 Kinetic and proteomic analyses of S -nitrosoglutathione-treated hexokinase A: consequences for cancer energy metabolism [Elektronische Daten] [S. Miller, C. Ross-Inta, C. Giulivi] Summary.: Mammalian hexokinase (HXK) is found at the outer mitochondrial membrane, exposed to mitochondrial oxygen- and nitrogen-radicals. Given the important role of this enzyme in metabolic pathways and diseases, the effect of S-nitrosoglutathione (GSNO) on HXK A structure and activity was studied. To focus on the catalytic domain, yeast HXK A was used because it has a significant homology to the mammalian domain that contains both the regulatory and catalytic sites. Biologically relevant [GSNO]/[HXK] caused a significant decrease in Vmax with glucose (but not with fructose), along with oxidation of 5 Met and nitration of 4 Tyr. Preincubation of HXK with glucose abrogated the effect of GSNO whereas fructose was ineffective. These results are interpreted by considering the tight binding of glucose to the enzyme as opposed to that of fructose. The segment comprised from amino acids 304 to 306 contained the most modifications. Given that this sequence is highly conserved in HXK from various species, a decline in activity is expected when a high-affinity substrate is presented. Considering that changes in primary structure are envisioned at high [GSNO]/[HXK] ratios, like those present under normal conditions, it could be hypothesized that the high concentration of hexokinase present in fast growing tumors may serve not only to sustain high glycolysis rates, but also to minimize protein damage that might result in activity decline, compromising energy metabolism. Springer-Verlag, 2006 Keywords: Nitrosoglutathione - Hexokinase - Structure - Activity - Oxygen radicals - Nitrogen radicals - Proteomics - Tumor - Glycolysis nationallicence Miller S. Department of Molecular Biosciences, University of California, Davis, CA, U.S.A. aut Ross-Inta C. Department of Molecular Biosciences, University of California, Davis, CA, U.S.A. aut Giulivi C. Department of Molecular Biosciences, University of California, Davis, CA, U.S.A. aut Amino Acids Springer-Verlag 32/4(2007-05-01), 593-602 0939-4451 32:4<593 2007 32 726 https://doi.org/10.1007/s00726-006-0424-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00726-006-0424-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Miller S. Department of Molecular Biosciences, University of California, Davis, CA, U.S.A aut NATIONALLICENCE 700 1- Ross-Inta C. Department of Molecular Biosciences, University of California, Davis, CA, U.S.A aut NATIONALLICENCE 700 1- Giulivi C. Department of Molecular Biosciences, University of California, Davis, CA, U.S.A aut NATIONALLICENCE 773 0- Amino Acids Springer-Verlag 32/4(2007-05-01), 593-602 0939-4451 32:4<593 2007 32 726 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer