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Hermann Sahm - One of the best experts on this subject based on the ideXlab platform.
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enzymes involved in the formation of glycerol 3 phosphate and the by products Dihydroxyacetone and glycerol in zymomonas mobilis
Fems Microbiology Letters, 1994Co-Authors: Silke Horbach, Joachim Strohhacker, Roland Welle, Albert A De Graaf, Hermann SahmAbstract:In Zymomonas mobilis a novel pathway for the formation of glycerol 3-phosphate was identified by enzymatic studies and nuclear magnetic resonance spectroscopy. This pathway branches off from the Entner-Doudoroff pathway at the intermediate glyceraldehyde 3-phosphate and proceedes via Dihydroxyacetone phosphate, Dihydroxyacetone, glycerol to glycerol 3-phosphate. The reaction sequence is catalyzed by the enzymes triosephosphate isomerase (0.4 U (mg protein)−1), Dihydroxyacetone phosphatase (0.31 U (mg protein)−1), Dihydroxyacetone reductase (0.25 U (mg protein)−1), and glycerokinase (0.08 mU (mg protein)−1), respectively. The action of a postulated aldolase catalyzing the cleavage of fructose 6-phosphate to Dihydroxyacetone and glyceraldehyde 3-phosphate could be excluded.
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Enzymes involved in the formation of glycerol 3-phosphate and the by-products Dihydroxyacetone and glycerol in Zymomonas mobilis
FEMS Microbiology Letters, 1994Co-Authors: Silke Horbach, Joachim Strohhacker, Roland Welle, Albert A De Graaf, Hermann SahmAbstract:In Zymomonas mobilis a novel pathway for the formation of glycerol 3-phosphate was identified by enzymatic studies and nuclear magnetic resonance spectroscopy. This pathway branches off from the Entner-Doudoroff pathway at the intermediate glyceraldehyde 3-phosphate and proceedes via Dihydroxyacetone phosphate, Dihydroxyacetone, glycerol to glycerol 3-phosphate. The reaction sequence is catalyzed by the enzymes triosephosphate isomerase (0.4 U (mg protein)−1), Dihydroxyacetone phosphatase (0.31 U (mg protein)−1), Dihydroxyacetone reductase (0.25 U (mg protein)−1), and glycerokinase (0.08 mU (mg protein)−1), respectively. The action of a postulated aldolase catalyzing the cleavage of fructose 6-phosphate to Dihydroxyacetone and glyceraldehyde 3-phosphate could be excluded.
Kunio Ohmiya - One of the best experts on this subject based on the ideXlab platform.
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Purification and Characterization of Two Dihydroxyacetone Kinases from Schizosaccharomyces pombe IFO 0354.
Applied and environmental microbiology, 1996Co-Authors: K Yoshihara, Y Shimada, Shuichi Karita, Tetsuya Kimura, Kazuo Sakka, Kunio OhmiyaAbstract:Two Dihydroxyacetone kinases (DHAKs), DHAK I and DHAK II, were purified to homogeneity from Schizosaccharomyces pombe IFO 0354. They were immunologically different from each other. Although both of the enzymes had some affinity for glycerol and dl-glyceraldehyde in addition to Dihydroxyacetone and glyceraldehyde, V(infmax) values for Dihydroxyacetone were much higher than those for glycerol and dl-glyceraldehyde. On the basis of the K(infm) values of both enzymes for Dihydroxyacetone, DHAK II plays a more important role than DHAK I in dissimilation of glycerol via Dihydroxyacetone.
Silke Horbach - One of the best experts on this subject based on the ideXlab platform.
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enzymes involved in the formation of glycerol 3 phosphate and the by products Dihydroxyacetone and glycerol in zymomonas mobilis
Fems Microbiology Letters, 1994Co-Authors: Silke Horbach, Joachim Strohhacker, Roland Welle, Albert A De Graaf, Hermann SahmAbstract:In Zymomonas mobilis a novel pathway for the formation of glycerol 3-phosphate was identified by enzymatic studies and nuclear magnetic resonance spectroscopy. This pathway branches off from the Entner-Doudoroff pathway at the intermediate glyceraldehyde 3-phosphate and proceedes via Dihydroxyacetone phosphate, Dihydroxyacetone, glycerol to glycerol 3-phosphate. The reaction sequence is catalyzed by the enzymes triosephosphate isomerase (0.4 U (mg protein)−1), Dihydroxyacetone phosphatase (0.31 U (mg protein)−1), Dihydroxyacetone reductase (0.25 U (mg protein)−1), and glycerokinase (0.08 mU (mg protein)−1), respectively. The action of a postulated aldolase catalyzing the cleavage of fructose 6-phosphate to Dihydroxyacetone and glyceraldehyde 3-phosphate could be excluded.
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Enzymes involved in the formation of glycerol 3-phosphate and the by-products Dihydroxyacetone and glycerol in Zymomonas mobilis
FEMS Microbiology Letters, 1994Co-Authors: Silke Horbach, Joachim Strohhacker, Roland Welle, Albert A De Graaf, Hermann SahmAbstract:In Zymomonas mobilis a novel pathway for the formation of glycerol 3-phosphate was identified by enzymatic studies and nuclear magnetic resonance spectroscopy. This pathway branches off from the Entner-Doudoroff pathway at the intermediate glyceraldehyde 3-phosphate and proceedes via Dihydroxyacetone phosphate, Dihydroxyacetone, glycerol to glycerol 3-phosphate. The reaction sequence is catalyzed by the enzymes triosephosphate isomerase (0.4 U (mg protein)−1), Dihydroxyacetone phosphatase (0.31 U (mg protein)−1), Dihydroxyacetone reductase (0.25 U (mg protein)−1), and glycerokinase (0.08 mU (mg protein)−1), respectively. The action of a postulated aldolase catalyzing the cleavage of fructose 6-phosphate to Dihydroxyacetone and glyceraldehyde 3-phosphate could be excluded.
Adam Poulos - One of the best experts on this subject based on the ideXlab platform.
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exclusive localization in peroxisomes of Dihydroxyacetone phosphate acyltransferase and alkyl Dihydroxyacetone phosphate synthase in rat liver
Journal of Lipid Research, 1993Co-Authors: Harmeet Singh, K Beckman, Adam PoulosAbstract:Dihydroxyacetone phosphate acyl transferase (DHAP-AT), alkyl Dihydroxyacetone phosphate synthase (alkyl- DHAP-synthase), and glycerol-3-phosphate acyltransferase (GPAT) activities were investigated under optimal assay condi- tions using highly purified organelle preparations. The data presented clearly indicate that GPAT activity was mainly local- ized in mitochondria and microsomes, whereas DHAP-AT and alkyl-DHAP-synthase activities were exclusively localized in peroxisomes. A small fraction of the total DHAP-AT and alkyl- DHAP-synthase activities observed in purified mitochondrial preparations was due to the presence of intact peroxisomes. DHAP-AT and alkyl-DHAP-synthase activities were very low in purified microsomes (< 1% compared to peroxisomes) and these activities are thought to be due to sedimentation of perox- isomal fragments (generated during homogenization of liver and processing of liver homogenate) with microsomes. The results indicate that the Dihydroxyacetone phosphate pathway does not contribute to the synthesis of glycerolipids other than ether lipids in rat liver. The ether bond formation occurs exclu- sively in peroxisomes, and all the biosynthetic reactions for plas- malogen synthesis may also be operating within peroxisomes in rat liver.-Singh, H., K. Beckman, and A. Poulos. Exclusive localization in peroxisomes of Dihydroxyacetone phosphate acyltransferase and alkyl-Dihydroxyacetone phosphate synthase in rat liver. J. Lipid Res. 1993. 34: 467-477.
Anna W. M. Zomer - One of the best experts on this subject based on the ideXlab platform.
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Alkyl Dihydroxyacetone phosphate synthase in glycosomes of Trypanosoma brucei.
Biochimica et Biophysica Acta, 1995Co-Authors: Anna W. M. Zomer, Frederik Opperdoes, H. BoschAbstract:Alkyl-Dihydroxyacetone phosphate synthase (E.C. 2.5.1.26), the key enzyme in ether phospholipid biosynthesis, was demonstrated to be present in Trypanosoma brucei. The distribution of alkyl-Dihydroxyacetone phosphate synthase was found to be identical to that of Dihydroxyacetone phosphate acyltransferase (E.C. 2.3.1.42), which has previously been shown to be exclusively associated with the glycosome fraction (Opperdoes, F.R. (1984) FEBS Lett. 169, 35-39). Studies with gradient purified glycosomes indicated that the formation of alkyl-Dihydroxyacetone phosphate was completely dependent on the presence of acyl-Dihydroxyacetone phosphate. The glycosomal alkyl-Dihydroxyacetone phosphate synthase activity was characterized with respect to its pH optimum, Triton X-100 sensitivity and the dependency on the concentration of the substrates palmitoyl-Dihydroxyacetone phosphate and hexadecanol. Using thin-layer chromatographic and alkaline hydrolysis procedures the reaction product was identified as alkyl-Dihydroxyacetone phosphate. Alkyl-Dihydroxyacetone phosphate synthase was resistant to proteolytic inactivation by trypsin in intact glycosomes but not in Triton X-100 disrupted glycosomes. It is concluded that T. brucei glycosomes contain the enzymes responsible for glycero-ether bond formation analogous to mammalian peroxisomes.
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ether lipid synthesis purification and identification of alkyl Dihydroxyacetone phosphate synthase from guinea pig liver
Biochimica et Biophysica Acta, 1993Co-Authors: Anna W. M. Zomer, Wim F C De Weerd, Jan Langeveld, Henk Van Den BoschAbstract:Abstract Alkyl-Dihydroxyacetone phosphate synthase, the second enzyme involved in ether phospholipid biosynthesis from Dihydroxyacetone phosphate and responsible for glycero-ether bond formation, has been purified from guinea-pig liver. Alkyl-Dihydroxyacetone phosphate synthase was solubilized from a membrane fraction prepared from an enriched peroxisome fraction with Triton X-100 and potasssium chloride. The solubilized enzyme was further purified by chromatography on QAE-Sephadex, Matrex Red, Phosphocellulose and Concanavalin A. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis alkyl-Dihydroxyacetone phosphate synthase appears as a 65 kDa band. Chromatofocusing revealed an isoelectric point of pH 5.9 for the enzyme. The pH optimum of alkyl-Dihydroxyacetone phosphate synthase was found to be between pH 7 and 8 in a 50 mM potassium phosphate buffer. The specific activity of the enzyme was estimated to be at least 350 nmol · min −1 · mg −1 , corresponding to a purification of at least 13 000-fold.