TY - JOUR
T1 - Influence of cyanide on diauxic oscillations in yeast
AU - Hald, Bjørn Olav
AU - Smrcinova, Miroslava
AU - Sørensen, Preben Graae
N1 - © 2012 The Authors Journal compilation © 2012 FEBS.
PY - 2012/12
Y1 - 2012/12
N2 - Coherent glycolytic oscillations in Saccharomyces cerevisiae are a multicellular property induced by addition of glucose to a starved cell population of sufficient density. However, initiation of oscillations requires an additional perturbation, usually addition of cyanide. The fate of cyanide during glycolytic oscillations has not previously been studied, and is the subject of the present paper. Using a cyanide electrode, a substantial decrease in cyanide concentration was observed. In the pH range 6-7, we found experimentally that the electrode behaves reasonably well, provided changes in pH are taken into account. To our knowledge, use of a cyanide electrode to study cyanide dynamics in living biological systems is new. Cyanide was found to enter starving yeast cells in only negligible amounts, and did not react significantly with glucose. Thus, cyanide consumption must be explained by reactions with glycolytic intermediates and evaporation. Evaporation and reaction with the signalling substance, extracellular acetaldehyde (ACA x) only explains the observed cyanide removal if [ACAx] is improbably high. Furthermore, differences in NADH traces upon cyanide addition before or after glucose addition strongly suggest that cyanide also reacts with intracellular carbonyl-containing metabolites. We show that cyanide reacts with pyruvate (Pyr) and dihydroxyacetone phosphate in addition to ACA, and estimate their rate constants. Our results strongly suggest that the major routes of cyanide removal during glycolysis are reactions with pyruvate and ACA. Cyanide removal by all carbonyl-containing intermediates led to a lower mean [ACA x], thereby increasing the amplitude of [ACAx] oscillations. Database The mathematical model described here has been submitted to the JWS Online Cellular Systems Modelling Database and can be accessed at http://jjj.biochem.sun.ac.za/database/hald/index.html free of charge. Observation of glycolytic oscillations in Saccharomyces cerevisiae usually requires addition of glucose and cyanide to a starved cell population. Using a cyanide electrode, cyanide removal routes during oscillations were studied. Extracellularly, a substantial decrease in cyanide concentration was observed. It was found that cyanide reacts in significant amounts with intracellular pyruvate and dihydroxy-acetone-phosphate as well as extracellular acetaldehyde
AB - Coherent glycolytic oscillations in Saccharomyces cerevisiae are a multicellular property induced by addition of glucose to a starved cell population of sufficient density. However, initiation of oscillations requires an additional perturbation, usually addition of cyanide. The fate of cyanide during glycolytic oscillations has not previously been studied, and is the subject of the present paper. Using a cyanide electrode, a substantial decrease in cyanide concentration was observed. In the pH range 6-7, we found experimentally that the electrode behaves reasonably well, provided changes in pH are taken into account. To our knowledge, use of a cyanide electrode to study cyanide dynamics in living biological systems is new. Cyanide was found to enter starving yeast cells in only negligible amounts, and did not react significantly with glucose. Thus, cyanide consumption must be explained by reactions with glycolytic intermediates and evaporation. Evaporation and reaction with the signalling substance, extracellular acetaldehyde (ACA x) only explains the observed cyanide removal if [ACAx] is improbably high. Furthermore, differences in NADH traces upon cyanide addition before or after glucose addition strongly suggest that cyanide also reacts with intracellular carbonyl-containing metabolites. We show that cyanide reacts with pyruvate (Pyr) and dihydroxyacetone phosphate in addition to ACA, and estimate their rate constants. Our results strongly suggest that the major routes of cyanide removal during glycolysis are reactions with pyruvate and ACA. Cyanide removal by all carbonyl-containing intermediates led to a lower mean [ACA x], thereby increasing the amplitude of [ACAx] oscillations. Database The mathematical model described here has been submitted to the JWS Online Cellular Systems Modelling Database and can be accessed at http://jjj.biochem.sun.ac.za/database/hald/index.html free of charge. Observation of glycolytic oscillations in Saccharomyces cerevisiae usually requires addition of glucose and cyanide to a starved cell population. Using a cyanide electrode, cyanide removal routes during oscillations were studied. Extracellularly, a substantial decrease in cyanide concentration was observed. It was found that cyanide reacts in significant amounts with intracellular pyruvate and dihydroxy-acetone-phosphate as well as extracellular acetaldehyde
U2 - 10.1111/febs.12030
DO - 10.1111/febs.12030
M3 - Journal article
C2 - 23072639
SN - 1742-4658
VL - 279
SP - 4410
EP - 4420
JO - The F E B S Journal (Online)
JF - The F E B S Journal (Online)
IS - 23
ER -