title: Regulation of the activity of lactate dehydrogenases from four lactic acid bacteria.
abstract: Despite high similarity in sequence and catalytic properties, the l-lactate dehydrogenases (LDHs) in lactic acid bacteria (LAB) display differences in their regulation that may arise from their adaptation to different habitats. We combined experimental and computational approaches to investigate the effects of fructose 1,6-bisphosphate (FBP), phosphate (Pi), and ionic strength (NaCl concentration) on six LDHs from four LABs studied at pH 6 and pH 7. We found that 1) the extent of activation by FBP (Kact) differs. Lactobacillus plantarum LDH is not regulated by FBP, but the other LDHs are activated with increasing sensitivity in the following order: Enterococcus faecalis LDH2 ≤ Lactococcus lactis LDH2 < E. faecalis LDH1 < L. lactis LDH1 ≤ Streptococcus pyogenes LDH. This trend reflects the electrostatic properties in the allosteric binding site of the LDH enzymes. 2) For L. plantarum, S. pyogenes, and E. faecalis, the effects of Pi are distinguishable from the effect of changing ionic strength by adding NaCl. 3) Addition of Pi inhibits E. faecalis LDH2, whereas in the absence of FBP, Pi is an activator of S. pyogenes LDH, E. faecalis LDH1, and L. lactis LDH1 and LDH2 at pH 6. These effects can be interpreted by considering the computed binding affinities of Pi to the catalytic and allosteric binding sites of the enzymes modeled in protonation states corresponding to pH 6 and pH 7. Overall, the results show a subtle interplay among the effects of Pi, FBP, and pH that results in different regulatory effects on the LDHs of different LABs.
authors.affiliation: From the Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies, 69118 Heidelberg, Germany,; BioQuant and.
authors.forename: Anna
authors.initials: A
authors.lastname: Feldman-Salit
authors.affiliation: Institute of Medical Microbiology, Virology, and Hygiene, University Medicine Rostock, 18057 Rostock, Germany.
authors.forename: Silvio
authors.initials: S
authors.lastname: Hering
authors.affiliation: Manchester Centre for Integrative Systems Biology, MIB, The University of Manchester, Manchester M1 7DN, United Kingdom, and.
authors.forename: Hanan L
authors.initials: HL
authors.lastname: Messiha
authors.affiliation: From the Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies, 69118 Heidelberg, Germany,; BioQuant and.
authors.forename: Nadine
authors.initials: N
authors.lastname: Veith
authors.affiliation: From the Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies, 69118 Heidelberg, Germany.
authors.forename: Vlad
authors.initials: V
authors.lastname: Cojocaru
authors.affiliation: Institute of Medical Microbiology, Virology, and Hygiene, University Medicine Rostock, 18057 Rostock, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Sieg
authors.affiliation: Manchester Centre for Integrative Systems Biology, MIB, The University of Manchester, Manchester M1 7DN, United Kingdom, and; Synthetic Systems Biology, SILS, the University of Amsterdam, and Molecular Cell Physiology, FALW, Netherlands Institute for Systems Biology, VU University Amsterdam, NL-1018 HV Amsterdam, The Netherlands.
authors.forename: Hans V
authors.initials: HV
authors.lastname: Westerhoff
authors.affiliation: Institute of Medical Microbiology, Virology, and Hygiene, University Medicine Rostock, 18057 Rostock, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Kreikemeyer
authors.affiliation: From the Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies, 69118 Heidelberg, Germany,; Center for Molecular Biology, Heidelberg University, 69120 Heidelberg, Germany,. Electronic address: rebecca.wade@h-its.org.
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Wade
authors.affiliation: Institute of Medical Microbiology, Virology, and Hygiene, University Medicine Rostock, 18057 Rostock, Germany,. Electronic address: tomas.fiedler@med.uni-rostock.de.
authors.forename: Tomas
authors.initials: T
authors.lastname: Fiedler
mesh_terms: D000494:Allosteric Regulation / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects / Q000201:enzymology*; D001665:Binding Sites; D055162:Biocatalysis / Q000187:drug effects; D018360:Crystallography, X-Ray; D004789:Enzyme Activation / Q000187:drug effects; D005635:Fructosediphosphates / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007527:Isoenzymes / Q000378:metabolism; D007700:Kinetics; D045022:Lactate Dehydrogenases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D019344:Lactic Acid / Q000378:metabolism*; D008954:Models, Biological; D010710:Phosphates / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D055672:Static Electricity
chemical_list: D005635:Fructosediphosphates; D007527:Isoenzymes; D010710:Phosphates; D019344:Lactic Acid; D012965:Sodium Chloride; D045022:Lactate Dehydrogenases; C029063:fructose-1,6-diphosphate
keywords: Allosteric Regulation; Bacterial Metabolism; Dehydrogenase; Enzyme Kinetics; Homology Modeling; Lactate Dehydrogenase; Lactic Acid Bacteria; Molecular Interaction Field; Protein Electrostatics