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1.
The occurrence of adenosine 5-triphosphate-3-diphosphate-synthesizing activity was detected in five strains of actinomycetes; Streptomyces morookaensis, Streptomyces aspergilloides, Streptomyces hachijoensis, Actinomyces violascens and Streptoverticillium septatum, out of 825 strains of actinomycetes, bacteria, fungi and imperfecti. Purine nucleotide pyrophosphotransferase were extracellularly excreted associating with the cell growth, and were purified partially or to apparent homogeniety from the culture filtrate. The enzymes are a monomeric protein with a molecular weight of 18000–26000 and synthesize adenosine, guanosine and inosine 5-phosphate (mono, di or tri)-3-diphosphate such as pApp, ppApp, pppApp, pGpp, ppGpp, pppGpp and pppIpp by transferring a pyrophosphoryl group from the 5-position of ATP, dATP and pppApp to the 3-position of purine nucleotides in the presence of a divalent cation and in alkaline state.Abbreviations pppApp adenosine 5-triphosphate 3-diphosphate - ppApp adenosine 5-diphosphate 3-diphosphate - pApp adenosine 5-monophosphate 3-diphosphate - pppGpp guanosine 5-triphosphate 3-diphosphate  相似文献   

2.
Summary The self-condensation of 2(3)-O-glycyl esters of adenosine, adenosine-5-(O-methylphosphate) and P1, P2-diadenosine-5-pyrophosphate in 6.2 mM solutions at pH 8.0 and -5°C in the presence of 12.5 mM poly(U) yields approximately 3 times as much diketopiperazine as reactions without poly(U). As the concentration of 2(3)-O-(glycyl)-P1, P2-diadenosine-5-pyrophosphate is decreased from 6.2 mM to 1.5 mM the yield of diketopiperazine in the presence of poly(U) decreases slightly from 6.6% to 5.2%, whereas, in the absence of poly(U) the yield of diketopiperazine decreases substantially from 2.4% to 0.75%. The enhanced yield of diketopiperazine that is attributed to the template action of poly(U) is temperature dependent and is observed only at temperatures below 10°C (5°C to -5°C) for 6.2 mM 2(3)-O-(glycyl)-adenosine-5-(O-methylphosphate) and below 23°C (15°C to -5°C) for 6.2 mM 2(3)-O-(glycyl)-P1, P2-diadenosine-5-pyrophosphate. The absence of a template effect at high temperatures is attributed to the melting of the organized helices. The hydrolysis half-lives at pH 8.0 and -5°C of 2(3)-O-(glycyl)-adenosine, 2(3)-O-(glycyl)-adenosine-5-(O-methylphosphate), 2(3)-O-(glycyl)-P1, P2-diadenosine-5-pyrophosphate, and 5-O-(glycyl)-adenosine in the presence of poly(U) are substantially larger than their half-lives in the absence of poly(U). The condensation of 2(3)-O-(glycyl)-adenosine yields 5% of 5-O-(glycyl)-adenosine in the presence of poly(U) compared to 0.7% in the absence of poly(U).Abbreviations DKP diketopiperazine - (gly)2 glycylglycine - (gly)3 glycylglycylglycine - AppA-gly 2(3)-O-(glycyl)-P1, P2-diadenosine-5-pyrophosphate - MepA-gly 2(3)-O-(glycyl)-adenosine-5-(O-methylphosphate) - Ado-2(3)-gly 2(3)-O-(glycyl)-adenosine - Ado-5-gly 5-O-(glycyl)-adenosine - Boc-gly N-tert-butyloxycarbonylglycine - AppA P1, P2-diadenosine-5-pyrophosphate - MepA adenosine-5-(O-methylphosphate) - AppA-Boc-gly 2(3)-O-(Boc-glycyl)-P1, P2-diadenosine-5-pyrophosphate - Ado-5-Boc-gly 5-O-(Boc-glycyl)-adenosine - Ado-2(3)-Boc-gly 2(3)-O-(Boc-glycyl)-adenosine  相似文献   

3.
The cleavage of adenosine-5-monophosphate (5-AMP) and guanosine-5-monophosphate (5-GMP) by Ce4+ and lanthanide complex of 2-carboxyethylgermanium sesquioxide (Ge-132) in acidic and near neutral conditions was investigated by NMR , HPLC and measuring the liberated inorganic phosphate at 37°C and 50°C. The results showed that 5-GMP and 5-AMP was converted to guanine (G), 5-monophosphate (depurination of 5-GMP), ribose (depurination and dephosphorylation of 5-GMP), phosphate and adenine (A), 5-monophosphate (depurination of 5-AMP), ribose (depurination and dephosphorylation of 5-AMP), phosphate respectively by Ce4+. In presence of lanthanide complexes, 5-GMP and 5-AMP were converted to guanosine (Guo) and phosphate and adenosine (Ado) and phosphate respectively. The mechanism of cleaving 5-GMP and 5-AMP is hydrolytic scission  相似文献   

4.
Crude extracts or supernatants of broken cells of Clostridium formicoaceticum reduce unbranched, branched, saturated and unsaturated carboxylates at the expense of carbon monoxide to the corresponding alcohols. The presence of viologens with redox potentials varying from E 0=-295 to-650 mV decreased the rate of propionate reduction. The more the propionate reduction was diminished the more formate was formed from carbon monoxide. The lowest propionate reduction and highest formate formation was observed with methylviologen. The carbon-carbon double bond of E-2-methyl-butenoate was only hydrogenated when a viologen was present. Formate as electron donor led only in the presence of viologens to the formation of propanol from propionate. The reduction of propionate at the expense of a reduced viologen can be followed in cuvettes. With respect to propionate Michaelis Menten behavior was observed. Experiments are described which lead to the assumption that the carboxylates are reduced in a non-activated form. That would be new type of biological reduction.Non-standard abbreviations glc Gas liquid chromatography - HPLC high performance liquid chromatography - RP reverse phase; Mediators (the figures in parenthesis of the mediators are redox potentials E 0 in mV) - CAV2+ carbamoylmethylviologen, 1,1-carbamoyl-4,4-dipyridinium dication (E 0=-296 mV) - BV2+ benzylviologen, 1,1-dibenzyl-4,4-dipyridinium dication (E 0=-360 mV) - MV methylviologen, 1,1-dimethyl-4,4-dipyridinium-dication (E 0=-444 mV) - DMDQ2+ dimethyldiquat, 4,4-dimethyl-2,2-dipyridino-1,1-ethylendication (E 0=-514 mV) - TMV2+ tetramethylviologen, 1,1,4,4-tetramethyl-4,4-dipyridinium dication (E 0=-550 mV) - PDQ2+ propyldiquat, 2,2-dipyridino-1,1-propenyl dication (E 0=-550 mV) - DMPDQ2+ dimethylpropyldiquat, 4,4-dimethyl-2,2-dipyridino-1,1-propenyl dication (E 0=-656 mV) - PN productivity number=mmol product (obtained by the uptake of one pair of electrons) x (biocatalyst (dry weight) kg)-1×h-1  相似文献   

5.
Summary Soluble lead salts and a number of lead-containing minerals catalyze the formation of oligonucleotides from nucleoside 5-phosphorimidazolides. The effectiveness of lead compounds correlates strongly with their solubility. Under optimal conditions we were able to obtain 18% of pentamer and higher oligomers from ImpA. Reactions involving ImpU gave smaller yields.Abbreviations A adenosine - U uridine - Im imidazole - MeIm 1-methyl-imidazole - EDTA ethylenediaminetetraacetic acid - pA adenosine 5-phosphate - pU uridine 5-phosphate - Ap adenosine cyclic 2:3-phosphate - ATP adenosine 5-triphosphate - AppA P1,P2-diadenosine 5-diphosphate - pNp (N = A,U) nucleotide 2(3), 5-diphosphate - ImpA adenosine 5-phosphoreimidazolide - ImpU uridine 5-phosphorimidazolide - A 2pA adenylyl-[25]-adenosine - A 3pA adenylyl-[35]-adenosine - pA 2pA 5-phospho-adenylyl-[25]-adenosine - pA 3pA 5-phospho-adenylyl-[35]-adenosine - pUpU 5-phospho-uridylyl-uridine - pApU 5-phospho-adenylyl-uridine - pUpA 5-phospho-uridylyladenine - (pA)n (n, 2,3,4,) oligoadenylates with 5 terminal phosphate - ImpApA 5-phosphorimidazolide of adenylyl adenosine - (pA) 5+ pentamer and higher oligoadenylates with 5 terminal phosphate - (Ap)nA (n = 2,3,4) oligoadenylates without terminal phosphates In the following we do not specify the nature of the internucleotide linkageIn the following we do not specify the nature of the internucleotide linkage  相似文献   

6.
The six binary montmorillonite clay-catalyzed reactions of the5-phosphorimidazolides of adenosine, cytidine, guanosine anduridine were performed and the eight dimers from each reactionwere separated and analyzed by HPLC. A 16–51-fold higher yieldof the 5-purine-pyrimidine dimers over that of the5-pyrimidine-purines was observed. The total yield of the5-purine-pyrimidine dimers was in the 50–70% range while thatof the 5-pyrimidine-purine dimers was 1.3–7.0%. Less sequenceselectivity was observed in the homodimers formed.Regioselectivity for the formation of 3, 5-phosphodiesterbonds over that found in the absence of clay was observed. The5-purine-pyrimidine, 5-pyrimidine-pyrimidine and5-purine-purine dimers had 3, 5-links in about half of theirphosphodiester bonds. The percent phosphodiester links in the5-pyrimidine-pyrimidine dimers was 18%, a value close to thatobserved in the absence of the montmorillonite catalyst. Themontmorillonite-catalyzed reaction of all four activatednucleotides was performed and the 24 products were separated andanalyzed. The trends observed in the binary reactions wereconfirmed and the results also showed that the relativereactivity of the activated monomers was A>G>C>U in theratio 8.2: 4.8: 1.3: 1 respectively. No 5-pyrimidine-purineswith a 5-U and pG3pU, pC3pAand pC3pG weredetected. These studies suggest that a limited population ofRNAs would have formed in catalyzed prebiotic reactions.  相似文献   

7.
M. Grün  G. Franz 《Planta》1981,152(6):562-564
Biosynthetic studies with cell-free extracts from Aloe arborescens Mill. demonstrate the transfer of the glucose moiety from UDP-glucose to aloe emodin anthrone, forming the C-glycosidic linkage in the anthracene derivative aloin. The pH-dependence and the specificity of UDP-glucose and aloe emodin anthrone for the biosynthesis of the C-glycosidic bond in aloin are shown.Abbreviations ADP-Glc adenosine-5-diphosphate glucose - AEA aloe emodin anthrone (1,8-dihydroxy-3-(hydroxymethyl)-9(10 H)-anthracenone) - CoASAc acetyl coenzyme A - GDP-Glc guanosine-5-diphosphate glucose - Glc glucose - Glc-1-P glucose-1-phosphate - HPLC high performance liquid chromatography - TLC thin layer chromatography - UDP-Gal uridine-5-diphosphate galactose - UDP-Glc uridine-5-diphosphate glucose  相似文献   

8.
Plausible prebiotic conditions for the phosphorylation of nucleosides by inorganic phosphate were reported by Lohrmann and Orgel in 1971. This reaction was carried out on heated dry films and promoted by urea. The major products formed were nucleoside-2:3 cyclicPs; 5-NMPs and other derivatives were also formed. Minor modifications of the Lohrmann and Orgel system have resulted in the preferential formation of 5-NMPs. In this modified system a 2-fold preference for phosphorylation of the 5-OH group over the 3(2)-OH group was observed and the formation of other derivatives was minimized. The small amounts of bis compounds that were formed in this system could be quantitatively removed by selective binding to the mineral hydroxylapatite at moderate ionic strengths. It was also discovered that under hydrolytic conditions there was a 3:1 preference for removal of phosphates attached to the 3-OH group over the 5-OH group. A recycling procedure for obtaining additional 5-NMPs from bis compounds and 3-NMPs is proposed.  相似文献   

9.
Summary The carotenoid pigments of the myxobacterium Sorangium compositum were analyzed by chromatographical and chemical techniques and by visible, infra red, and mass spectroscopy. Besides -carotene, neurosporene, torulene, lycopene, and 1,2-dihydro-1-hydroxy--carotene, four new carotenoid glycosides were found. These pigments were identified as 1,2-dihydro-1-hydroxy-torulene glucoside ester (I), 1,2-dihydro-3,1-dihydroxy-torulene glucoside ester (III), 1,2-dihydro-1-hydroxy-torulene rhamnoside (II), and 1,2-dihydro-3,1-dihydroxytorulene rhamnoside (IV).Fifth communication on the carotenoids of myxobacteria. Fourth communication see Arch. Mikrobiol. 76, 364–380 (1971).  相似文献   

10.
Summary To get more insight in the function of 5-nucleotidase catabolic and anabholic processes were investigated in which 5-nucleotides are involved. The catabolism of adenosine-5-monophosphate was studied by investigating the reaction products obtained after incubation of homogenates of several organs of rat and mouse with adenosine-5-monophosphate and with adenosine. Two experimental tumours of the mouse were investigated in the same way. It was found that in tissues containing a high activity of 5-nucleotidase other enzymes involved in the catabolism of 5-nucleotides, such as nucleosidase, adenosine deaminase and adenosine-5-monophosphate deaminase could also be demonstrated.The anabolic processes in which 5-nucleotides are involved had been studied by investigating the incorporation of tritium-labeled thymidine in several tissues of the mouse. It appeared that in cells showing a high 5-nucleotidase activity no incorporation of radioactive thymidine could be found, while in cells showing incorporation of thymidine enzyme activity could not be demonstrated.A discussion is given about the possible role of 5-nucleotidase in the control of nucleic acid biosynthesis and in the catabolism of nucleic acids.Abbreviations used DNA deoxyribonucleic acid - RNA ribonucleic acid - AMP Adenosine-5-monophosphate - ADP Adenosine-5-diphosphate - ATP Adenosine-5-triphosphate - IMP Inosine-5-monophosphate - GMP Guanosine-5-monophosphate - GDP Guanosine-5-diphosphate - GTP guanosine-5-triphosphate - CMP Cytidine-5-monophosphate - CDP Cytidine-5-diphosphate - CTP Cytidine-5-triphosphate - UMP Uridine-5-monophosphate - UDP Uridine-5-diphosphate - UTP Uridine-5-triphosphate - TMP Thymidine-5-monophosphate - TDP Thymidine-5-diphosphate - TTP Thymidine-5-triphosphate - Ado Adenosine - Ad Adenine - Ino Inosine - Hypox Hypoxanthine - Xanth Xanthine - Xantho Xanthosine - Guano Guanosine - Gua Guanine - Ura Uracil - U Uridine - Cyt Cytidine - Cyto Cytosine - Thym Thymidine The corresponding deoxy-compounds have been indicated with the prefix d for instance dCMP, deoxycytidine-5-monophosphate.  相似文献   

11.
Summary Amino acids are activated by reaction with adenosine 5-phosphorimidazolide in aqueous imidazole buffers. If adenosine 5-(O-methylphosphate), an analogue of the 3-terminus of t-RNA is present, 2(3)-O-aminoacyladenosine 5-(O-methylphosphate) is formed. Fifteen percent of this compound accumulated at pH 5.8, but less was formed at higher pHs. The highest efficiency of utilization of ImpA attained in our experiments was about 24%. Analogous reactions occured with several other amino acids, including a number that have functional side-chains.Abbreviations pA adenosine 5-monophosphate - MepA adenosine-5-(O-methylphosphate) - ImpA adenosine-5-phosphorimidazolide - A adenosine - MepA-ala 2(3)-O-alanyl-adenosine-5-(O-methylphosphate) - ala-N-pA adenylyl-(5 N)-alanine - ImH imidazole - DKP diketopiperazine  相似文献   

12.
Females of the medfly, Ceratitis capitata, prefer sucrose solutions containing ribonucleotides to sucrose solutions without them. The order of preference for the nucleotides was: 5GMP>GTP>5CMP>5IMP >dGMP>5UMP>5AMP>5XMP=ATP=2 & 3GMP=RP>3AMP.2AMP, guanosine, inosine, adenine and 5TMP produced no significant stimulation. Females sterilized by irradiation showed reduced attraction to 5GMP as compared to non-irradiated females.Optimal molecular configuration for phagostimulation includes: phosphorylation at the 5 position of the ribose, free hydroxyl groups at 2 and 3 on the ribose, and an NH2 group at the 2 position of the aromatic ring of purine.It is proposed that the 5GMP in yeast hydrolyzate can be used as a measure of the suitability of the hydrolyzate as a bait.
Résumé La femelle de la mouche méditerranéenne des fruits, Ceratitis capitata, préfère les solutions de sucrose contenant des ribonucléotides aux simples solutions de sucrose. Lórdre de préférence pour les nucléotides est le suivant: 5GMP>GTP>5CMP>5IMP >dGMP>5UMP>5AMP>5XMP=ATP =2 & 3GMP=RP>3AMP.Le 2AMP, la guanosine, l'inosine, l'adénine et le 5TMP provoquent une stimulation significative. Les femelles montrent aprés stérilisation par irradiation une attirance réduite pour le 5GMP par comparaison avec les femelles non-irradiées.La configuration moléculaire optimale pour la phagostimulation comprend: la phosphorylation en position 5 du ribose; des groupes hydroxyles libres en 2 et 3 sur le ribose; et un groupe NH2 en position 2 sur le noyau aromatique.Nous proposons que le 5GMP dans l'hydrolysat de levure puisse être utilisé pour mesurer la capacité de l'hydrolysat comme appât.

Abbreviations 5AMP Adenosine 5-monophosphate - 3AMP Adenosine 3-monophosphate - 2AMP Adenosine 2-monophosphate - dAMP 2-deoxyadenosine 5-monophosphate - ADP Adenosine 5-diphosphate - ATP Adenosine 5-triphosphate - 5GMP Guanosine 5-monophosphate - 2GMP Guanosine 2-monophosphate - 3GMP Guanosine 3-monophosphate - dGMP 2-deoxyguanosine 5-monophosphate - GDP Guanosine 5-diphosphate - GTP Guanosine 5-triphosphate - 5IMP Inosine 5-monophosphate - IDP Inosine 5-diphosphate - ITP Inosine 5-triphosphate - 5XMP Xanthosine 5-monophosphate - 5CMP Cytidine 5-monophosphate - dCMP 2 deoxycytidine 5-monophosphate - CTP Cytidine 5-triphosphate - 5UMP Uridine 5-monophosphate - 5TMP Thymidine 5-monophosphate - RP Ribose 5 monophosphate  相似文献   

13.
Sequencing of a 3.4 kb DNA fragment isolated from the photosynthetic purple sulfur bacterium Chromatium vinosum and of PCR products has resulted in identification of the Chr. vinosum pufL, pufM, and pufC genes, reading from the 5 to the 3 direction, and coding, respectively, for the L, M and cytochrome c subunits of the reaction center of this bacterium. Other PCR products have been used to obtain complete sequences for the pufB and pufA genes, located immediately upstream from pufL and encoding the apoproteins of two Chr. vinosum light- harvesting proteins. The 3-portion of the bchZ gene, a gene that codes for a protein involved in the biosynthesis of bacteriochlorophyll, has been located immediately upstream from pufB. A second pufB gene, pufB2, has been located downstream from pufC, as has the 5-portion of a second pufA gene, pufA2. The location of a second set of pufB and pufA genes, encoding light- harvesting proteins, downstream from pufC has not previously been reported for any photosynthetic bacterium. Translation of the gene sequences encoding these Chr. vinosum light-harvesting proteins reveals both similarities to and differences from the amino acid sequences, obtained from direct sequencing of the apoproteins, previously reported for Chr. vinosum light-harvesting proteins. Translation of these gene sequences, and of those for pufL, pufM and pufC, revealed significant homology, at the amino acid level, to the corresponding peptides of photosynthetic purple non-sulfur bacteria.  相似文献   

14.
All stereoisomers of xanthoxin (XAN) and abscisic aldehyde (ABA-aldehyde) were prepared from (R) and (S)-4-hydroxy--cyclogeraniol via asymmetric epoxidation. Their stomatal closure activities were measured on epidermal strips of Commelina communis L. Natural (S)-ABA-aldehyde showed strong activity comparable to that of (S)-abscisic acid (ABA). Natural (1S, 2R, 4S)XAN and (1S, 2R, 4R)-epi-XAN also induced stomatal closure at high concentrations. On the other hand, unnatural (1R)-enantiomers of XAN, epi-XAN, and ABA-aldehyde were not effective. To further examine the Stereoselectivity on the biosynthetic pathway to ABA, deuterium-labeled substrates were prepared and fed to Lycopersicon esculentum Mill, under non-stressed or water-stressed conditions. Substantial incorporations into ABA were observed in the cases of natural (1S, 2R, 4S)-XAN, (1S, 2R, 4R)-epi-XAN and both enantiomers of ABA-aldehyde, leading to the following conclusions. The negligible effect of unnatural (1R)-enantiomers of XAN, epi-XAN and ABA-aldehyde can be explained by their own biological inactivity and/or their conversion to inactive (R)-ABA. Even in the isolated epidermal strips, putative aldehyde oxidase activity is apparently sufficient to convert ABA-aldehyde to ABA while the activity of XAN dehydrogenase seems very weak. The stereochemistry of the 1, 2-epoxide is very important for the XAN-dehydrogenase while this enzyme is less selective regarding the 4-hydrdxyl group of XAN and converts both (1S, 2R, 4S)-XAN and (1S, 2R, 4R)-epi-XAN to (S)-ABA-aldehyde. Abscisic aldehyde oxidase can nonstereoselectively convert both (S) and (R)-ABA-aldehyde to biologically active (S) and inactive (R)-ABA, respectively.Abbreviations ABA abscisic acid - ABA-aldehyde abscisic aldehyde - DET diethyl tartrate - epi-XAN xanthoxin epimer - FCC flash column chromatography - GC-EI-MS gas chromatography-electron impact-mass spectrometry - MeABA abscisic acid methyl ester - IR infrared - NMR nuclear magnetic resonance - PCC pyridinium chlorochromate - THF tetrahydrofuran - XAN xanthoxin The authors are very grateful to Mr J.K. Heald (Department of Biological Sciences, University of Wales, Aberystwyth, UK) and Dr. R. Horgan for carrying out GC-EI-MS analyses and advice, respectively.This work was supported by the Japan Society for the Promotion of Science (Fellowship for Young Japanese Researcher No. 0040672).  相似文献   

15.
Cardiolipin is one of the principle phospholipids in the mammalian heart comprising as much as 15–20% of the entire phospholipid phosphorus mass of that organ. Cardiolipin is localized primarily in the mitochondria and appears to be essential for the function of several enzymes of oxidative phosphorylation. Thus, cardiolipin is essential for production of energy for the heart to beat. Cardiac cardiolipin is synthesized via the cytidine-5-diphosphate-1,2-diacyl-sn-glycerol pathway. The properties of the four enzymes of the cytidine-5-diphosphate-1,2-diacyl-sn-glycerol pathway have been characterized in the heart. The rate-limiting step of this pathway is catalyzed by the phosphatidic acid: cytidine-5-triphosphate cytidylyltransferase. Several regulatory mechanisms that govern cardiolipin biosynthesis in the heart have been uncovered. Current evidence suggests that cardiolipin biosynthesis is regulated by the energy status (adenosine-5-triphosphate and cytidine-5-triphosphate level) of the heart. Thyroid hormone and unsaturated fatty acids may regulate cardiolipin biosynthesis at the level of three key enzymes of the cytidine-5-diphosphate-1,2-diacyl-sn-glycerol pathway, phosphatidylglycerolphosphate synthase, phosphatidylglycerolphosphate phosphatase and cardiolipin synthase. Newly synthesized phosphatidic acid and phosphatidylglycerol may be preferentially utilized for cardiolipin biosynthesis in the heart. In addition, separate pools of phosphatidylglycerol, including an exogenous (extra-mitochondrial) pool not derived from de novo phosphatidylglycerol biosynthesis, may be utilized for cardiac cardiolipin biosynthesis. In several mammalian tissues a significant number of studies on polyglycerophospholipid biosynthesis have been documented, including detailed studies in the lung and liver. However, in spite of the important role of cardiolipin in the maintenance of mitochondrial function and membrane integrity, studies on the control of cardiolipin biosynthesis in the mammalian heart have been largely neglected. The purpose of this review will be to briefly discuss cardiolipin and cardiolipin biosynthesis in some selected model systems and focus primarily on current studies involving the regulation of cardiolipin biosynthesis in the heart. (Mol Cell Biochem 159: 139–148, 1996)Abbreviations CL cardiolipin - PG phosphatidylglycerol - PA phosphatidic acid - CTP cytidine-5triphosphate - CDPDG cytidine-5'-diphosphate-1,2-diacyl-sn-glycerol - CMP cytidine-5monophosphate - lysoPG lysophosphatidylglycerol - monolysoCC monolysoCcardiolipin - BMP bis(monoacylglycerol)phosphate - ATP adenosine-5-triphosphate - ADP adenosine-5-diphosphate - PGP phosphatidylglycerol phosphate - DNA deoxyribonucleic acid - STZ streptozotocinM  相似文献   

16.
Summary In this first article on the carotenoids of Myxobacterales we report on the minor carotenoids of Stigmatella aurantiaca: phytoene, phytofluene, lycopene, -carotene, 4-keto--carotene, 1,2-dihydro-1-hydroxy--carotene, 4-keto-1,2-dihydro-1-hydroxy--carotene, 4-keto-1,2-dihydro-1-hydroxy-torulene, and 1,2,1,2-tetrahydro-1,1-dihydroxy-lycopene. These pigments account for about 10% of total carotenoids.  相似文献   

17.
Diiminosuccinonitrile (DISN), formed by the oxidation of diaminomaleonitrile (DAMN), has been investigated as a potential prebiotic phosphorylating agent. DISN effects the cyclization of 3-adenosine monophosphate to adenosine 2, 3-cyclic phosphate in up to 39% yield. The mechanism of this reaction was investigated. The DISN-mediated phosphorylation of uridine to uridine monophosphate does not proceed efficiently in aqueous solution. The reaction of DISN with uridine-5-phosphate and uridine results in the formation of 2,2-anhydronucleotides and 2,2-anhydronucleosides respectively, and other reaction products resulting from an initial reaction at the 2- and 3-hydroxyl groups. The clay mineral catalysis of the cyclization of adenosine-3-phosphate was investigated using homoionic montmorillonites.  相似文献   

18.
Structural analogues of the NADP+ were studied as potential coenzymes and inhibitors for NADP+ dependent malic enzyme from Zea mays L. leaves. Results showed that 1, N6-etheno-nicotinamide adenine dinucleotide phosphate ( NADP+), 3-acetylpyridine-adenine dinucleotide phosphate (APADP+), nicotinamide-hypoxanthine dinucleotide phosphate (NHDP+) and -nicotinamide adenine dinucleotide 2: 3-cyclic monophosphate (23NADPc+) act as alternate coenzymes for the enzyme and that there is little variation in the values of the Michaelis constants and only a threefold variation in Vmax for the five nucleotides. On the other hand, thionicotinamide-adenine dinucleotide phosphate (SNADP+), 3-aminopyridine-adenine dinucleotide phosphate (AADP+), adenosine 2-monophosphate (2AMP) and adenosine 2: 3-cyclic monophosphate (23AMPc) were competitive inhibitors with respect to NADP+, while -nicotinamide adenine dinucleotide 3-phosphate (3NADP+), NAD+, adenosine 3-monophosphate (3AMP), adenosine 2: 5-cyclic monophosphate (25AMPc), 5AMP, 5ADP, 5ATP and adenosine act as non-competitive inhibitors. These results, together with results of semiempirical self-consistent field-molecular orbitals calculations, suggest that the 2-phosphate group is crucial for the nucleotide binding to the enzyme, whereas the charge density on the C4 atom of the pyridine ring is the major factor that governs the coenzyme activity.Abbreviations NADP+ 1, N6-etheno-nicotinamide adenine dinucleotide phosphate - NHDP+ nicotinamide-hypoxanthine dinucleotide phosphate - APADP+ 3-acetylpyridine-adenine dinucleotide phosphate - SNADP+ thionicotinamide-adenine dinucleotide phosphate - AADP+ 3-aminopyridine-adenine dinucleotide phosphate - 23NADPc+ -nicotinamide adenine dinucleotide 2: 3-cyclic monophosphate - 3NADP+ -nicotinamide adenine dinucleotide 3-phosphate - 2AMP adenosine 2-monophosphate - 3AMP adenosine 3-monophosphate - 23AMPc adenosine 2: 3 monophosphate cyclic - A adenosine - RuBP ribulose 1,5-bisphosphate - SCF-MO Self-Consistent Field-Molecular Orbitals (method)  相似文献   

19.
The respiratory quinone composition of the obligate methane-utilizing bacterium Methylomonas rubra was examined. A single lipoquinone was isolated which on examination by thin-layer chromatography cochromatographed with coenzyme Q. Reverse-phase partition and argentation high performance liquid chromatography demonstrated the lipoquinone did not correspond to any known coenzyme Q prenologue. On the basis of mass spectrometry and proton nuclear magnetic resonance spectrometry the novel lipoquinone was shown to correspond to 2,3-dimethoxy-5-methyl-6-(11-methylene-3,7,15, 18, 18, 19, 23-heptamethyltetracosa-2, 6, 14, 19, 22-pentaenyl-)-1,4-benzoquinone.  相似文献   

20.
Summary We have used the cDNA clone encoding maize glutathione-S-transferase (GST I) to isolate a genomic DNA clone containing the complete GST I gene. Nucleotide sequence analysis of the cDNA and genomic clones has yielded a complete amino acid sequence for maize GST I and provided the exon-intron map of its gene. The mRNA homologous sequences in the maize GST I gene consist of a 107 bp 5 untranslated region, a 642 bp coding region and 340 bp of the 3 untranslated region. They are divided into three exons by two introns which interrupt the coding region. The 5 untranslated spacer contains an unusual sequence of pentamer AGAGG repeated seven times. The inbred maize line (Missouri 17) contains a single gene for GST I, whereas the hybrid line (3780A) contains two genes. Nucleotide sequence analysis of the primer extended cDNA products reveals that the 5 untranslated regions of the two genes in the hybrid 3780A are identical except for a 6 bp internal deletion (or insertion). The amino acid sequence of maize GST I shares no apparent sequence homology with the published sequences of animal GST's and represents the first published sequence of a plant GST. re]19850813 ac]19851126  相似文献   

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