title: Methylglyoxal and other carbohydrate metabolites induce lanthanum-sensitive Ca2+ transients and inhibit growth in E. coli.
abstract: The results here are the first demonstration of a family of carbohydrate fermentation products opening Ca2+ channels in bacteria. Methylglyoxal, acetoin (acetyl methyl carbinol), diacetyl (2,3 butane dione), and butane 2,3 diol induced Ca2+ transients in Escherichia coli, monitored by aequorin, apparently by opening Ca2+ channels. Methylglyoxal was most potent (K(1/2) = 1 mM, 50 mM for butane 2,3 diol). Ca2+ transients depended on external Ca2+ (0.1-10 mM), and were blocked by La3+ (5 mM). The metabolites affected growth, methylglyoxal being most potent, blocking growth completely up to 5 h without killing the cells. But there was no affect on the number of viable cells after 24 h. These results were consistent with carbohydrate products activating a La3+-sensitive Ca2+ channel, rises in cytosolic Ca2+ possibly protecting against certain toxins. They have important implications in bacterial-host cell signalling, and where numbers of different bacteria compete for the same substrates, e.g., the gut in lactose and food intolerance.
authors.affiliation: Department of Medical Biochemistry and Immunology, Cardiff University, Tenovus Building, Health Park, Cardiff CF14 XN, UK. campbellak@cf.ac.uk
authors.forename: Anthony K
authors.initials: AK
authors.lastname: Campbell
authors.forename: Riffat
authors.initials: R
authors.lastname: Naseem
authors.forename: I Barry
authors.initials: IB
authors.lastname: Holland
authors.forename: Stephanie B
authors.initials: SB
authors.lastname: Matthews
authors.forename: Kenneth T
authors.initials: KT
authors.lastname: Wann
mesh_terms: D000080:Acetals / Q000008:administration & dosage*; D000093:Acetoin / Q000008:administration & dosage*; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D050260:Carbohydrate Metabolism / Q000187:drug effects / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D003931:Diacetyl / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology*; D007811:Lanthanum / Q000008:administration & dosage*; D011765:Pyruvaldehyde / Q000008:administration & dosage*
chemical_list: D000080:Acetals; C442342:butane-2,3-diacetal glycolic acid; D007811:Lanthanum; D011765:Pyruvaldehyde; D000093:Acetoin; D003931:Diacetyl