ABSTRACT
New inhibitors of Ca2+ and calmodulin-dependent cyclic-nucleotide phosphodiesterase, KS-501 and KS-502 were isolated from a fungus, Sporothrix sp. KAC-1985. Inhibitory concentration causing 50% inhibition (IC50) values of KS-501 and KS-502 for bovine brain enzyme were 1.8 and 4.3 microM, respectively. The compounds exhibited no or weak inhibition for calmodulin-independent cyclic-nucleotide phosphodiesterases and protein kinase C.
Subject(s)
2',3'-Cyclic-Nucleotide Phosphodiesterases/antagonists & inhibitors , Calcium/metabolism , Hydroxybenzoates/biosynthesis , Sporothrix/metabolism , Calmodulin/metabolism , Chromatography, Gel , Chromatography, Thin Layer , Fermentation , Hydroxybenzoates/isolation & purification , Hydroxybenzoates/pharmacology , Molecular StructureABSTRACT
Salmonella typhi 541Ty has deletions at aroA and purA, causing requirement for aromatic metabolites (including p-aminobenzoate) and for adenine. None of 36 volunteers who drank 10(8) to 10(10) bacteria of 541Ty or its Vi-negative mutant 543Ty showed any adverse effect; all gave evidence of cellular immune response but only a few had serum titre increases. S. typhimurium experiments (at the Wellcome Research Laboratories and at Stanford) show that adenine requirement may reduce both bacterial survival in mouse tissues and live-vaccine efficacy. S. typhi attenuated only by block(s) in aromatic biosynthesis may be more effective as oral-route live vaccine.
Subject(s)
Bacterial Vaccines/isolation & purification , Salmonella typhi/immunology , 4-Aminobenzoic Acid/biosynthesis , Animals , Antibodies, Bacterial/biosynthesis , Forecasting , Genetic Variation , Humans , Hydroxybenzoates/biosynthesis , Immunity, Cellular , Mice , Salmonella typhi/metabolism , Vaccines, Attenuated/isolation & purificationSubject(s)
Aspirin/metabolism , Cell Aggregation/drug effects , Gentisates , Hydroxybenzoates/pharmacology , Neutrophils/drug effects , Arachidonic Acid , Arachidonic Acids/antagonists & inhibitors , Calcimycin/antagonists & inhibitors , Depression, Chemical , Fluorescence Polarization , Humans , Hydroxybenzoates/biosynthesis , Membrane Fluidity/drug effects , Neutrophils/metabolism , Neutrophils/physiology , Superoxides/biosynthesisABSTRACT
It has been shown that a 10 000 x g matrix-free mitochondrial membrane-rich preparation from commercial bakers' yeast is able to synthesize 3-all-transhexaprenyl-4-hydroxybenzoate from 4-hydroxybenzoate and isopentenyl pyrophosphate. The synthesis is Mg2+ dependent and is stimulated markedly by the primer for polyprenylpyrophosphate synthesis of 3-hexaprenyl-4-hydroxybenzoate from 4-hydroxybenzoate, isopentenyl pyrophosphate and 3,3-dimethylallyl pyrophosphate the priming function of 3,3-dimethylallyl pyrophosphate can be performed by either geranyl pyrophosphate (most efficient) or farnesyl pyrophosphate. At high Mg2+ concentrations, however, geranyl pyrophosphate and farnesyl pyrophosphate act mainly as sources of preformed side chains and 3-diprenyl- and 3-tripenyl-4-hydroxybenzoate, respectively, are produced. In the presence of a source of preformed polyprenyl pyrophosphates the membrane preparations catalysed the polyprenylation of methyl-4-hydroxybenzoate, 4-hydroxybenzaldehyde, 4-hydroxybenzylalcohol and 4-hydroxycinnamate. No evidence was obtained for the involvement of either 4-hydroxybenzoyl CoA or 4-hydroxybenzoyl-S-protein in the formation of 3-polyprenyl-4-hydroxybenzoates.
Subject(s)
Intracellular Membranes/metabolism , Mitochondria/metabolism , Terpenes/biosynthesis , Hydroxybenzoates/biosynthesis , Magnesium/pharmacology , Polyisoprenyl Phosphates/pharmacology , Saccharomyces cerevisiae/metabolismABSTRACT
1. Micrococcus denitrificans excretes three catechol-containing compounds, which can bind iron, when grown aerobically and anaerobically in media deficient in iron, and anaerobically in medium with a high concentration of Ca2+. 2. One of these compounds was identified as 2,3-dihydroxybenzoic acid (compound I), and the other two were tentatively identified as N1N8-bis-(2,3-dihydroxybenzoyl)spermidine (compound II) and 2-hydroxybenzoyl-N-L-threonyl-N4[N1N8-bis-(2,3-dihydroxybenzoyl)]spermidine (compound III). 3. The equimolar ferric complex of compound III was prepared; compound III also forms complexes with Al3+, Cr3+ and Co2+ ions. 4. Cell-free extracts from iron-deficient organisms catalyse the formation of compound II from 2,3-dihydroxybenzoic acid and spermidine, and of compound III from compound II, L-threonine and 2-hydroxybenzoic acid; both reactions require ATP and dithiothreitol, and Mg2+ stimulates activity. The enzyme system catalysing the formation of compound II has optimum activity at pH 8.8 Fe2+ (35muM), Fe3+ (35muM) and Al3+ (65muM) inhibit the reaction by 50 percent. The enzyme system forming compound III has optimum activity at pH 8.6. Fe2+ (110 muM), Fe3+ (110 muM) and Al3+ (135 muM) inhibit the reaction by 50 percent. 5. At least two proteins are required for the formation of compound II, and another two proteins for its conversion into compound III. 6. The changes in the activities of these two systems were followed after cultures became deficient in iron. 7. Ferrous 1,10-phenanthroline is formed when a cell-free extract from iron-deficient cells is incubated with the ferric complex of compound III, succinate, NADH and 1,10-phenanthroline under N2.
