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1.
Summary The temperature dependence of cytoplasmic streaming in intact and tonoplast-free cells ofNitellopsis obtusa was studied using a cryomicroscope. The streaming velocity decreases linearly with decrease in the temperature in well-buffered tonoplast-free cells but non-linearly in some intact cells. These results suggest that low temperature causes a disturbance in the homeostasis of calcium and protons, which inhibit cytoplasmic streaming in intact cells.Abbreviations ADP
adenosine 5-diphosphate
- APW
artificial pond water
- ATP
adenosine 5-triphosphate
- EGTA
ethylene glycol-bis(-aminoethyl ether)N,N,N-tetraacetic acid
- HEPES
N-(2-hydroxyethyl)piperazine-N-(2-ethanesulfonic acid)
- PIPES
piperazine-N, N-bis(2-ethanesulfonic acid)
- Tris
tris(hydroxymethyl)aminoethane 相似文献
2.
Summary The absence of the methyl substituent at the 2position of the cyclohexene ring of TCHP enhances the conversion rate as well as the yields of the 3-hydroxy product obtained byStreptomyces natalensis and the 3-keto product obtained byMycobacterium smegmatis.Abbreviations TCHP
1-(2-thienyl)-3-(1-cyclohexen-1-yl)-1-propanone
- TCHP-OH
1-(2-thienyl)-3-(3-hydroxyl-1-cyclohexen-1-yl)-1-propanone
- TCHP-ketone
1-(2-thienyl)-3-(1-cyclohexen-1-yl-3-one)-1-propane
- TMCHP
1-(2-thienyl)-3-(2-methyl-1-cyclohexen-1-yl)-propanone 相似文献
3.
Hans Kleinig Hans Reichenbach Hans Achenbach Jochen Stadler 《Archives of microbiology》1971,78(3):224-233
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
4.
Summary The plasmalemma ofNitella internode was made freely permeable to solutes by treating the cell with detergent and EGTA under plasmolysis. After the treatment, the cytoplasmic streaming was stopped by bathing the cell in a medium lacking ATP. The streaming was reactivated by perfusing the exterior of the permeabilized cell with a medium containing both Mg2+ and ATP. The reactivated streaming could be reversibly stopped by depletion of ATP. However, depletion of Mg2+ irreversibly inhibited the streaming.Cytochalasin B at 5 g/ml irreversibly inhibited the reactivated streaming within a minute, showing that microfilaments are involved in the streaming.Abbreviations ATP
adenosine-5-triphosphoric acid
- CB
cytochalasin B
- CyDTA
cyclohexanediamine-N,N-tetraacetic acid
- DMSO
dimethylsulfooxide
- DTT
dithiothreitol
- EGTA
ethyleneglycol-bis(-aminoethylether)-N,N tetraacetic acid
- PIPES
piperazine-N,N-bis(2-ethanesulfonic acid)
- PMSF
phenylmethyl-sulfonylfluoride 相似文献
5.
Summary 2-Amino-2-deoxyuridine reacts efficiently with nucleoside 5-phosphorimidazolides in aqueous solution. The dinucleoside monophosphate analogues were obtained in yields exceeding 80% under conditions in which little reaction occurs with the natural nucleosides.In a similar way, the 5-phosphorimidazolide of 2-amino-2-deoxyuridine undergoes self-condensation in aqueous solution to give a complex mixture of oligomers.The phosphoramidate bond in the dinucleoside monophosphate analogues is stable for several days at room temperature and pH 7. The mechanisms of their hydrolysis under acidic and alkaline conditions are described.Abbreviations A
adenosine
- C
cytidine
- G
guanosine
- U
uridine
- T
thymidine
- UN
3
2-azido-2-deoxyuridine
- UNH
2
2-amino-2-deoxyuridine
- ImpA
adenosine 5-phosphorimidazolide
- ImpU
uridine 5-phosphorimidazolide
- ImpUN
3
2-azido-2-deoxyuridine 5-phosphorimidazolide
- ImpUNH
2
2-amino-2-deoxyuridine 5-phosphorimidazolide
- pA
adenosine 5-phosphate
- pU
uridine 5-phosphate
- pUN
3
2-azido-2-deoxyuridine 5-phosphate
- pUNH
2
2-amino-2-deoxyuridine 5-phosphate
- UpA
uridylyl-[35]-adenosine
- UpU
uridylyl-[35]-uridine
- UNpA
adenylyl-[52]-2-amino-2-deoxy-uridine
- UNpU
uridylyl-[52]-2-amino-2-deoxyuridine (pUN)n n=2,3,4 [25]-linked oligomers of pUNH
2 poly(A) polyadenylic acid
- Im
imidazole
- MeIm
l-methylimidazole 相似文献
6.
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
7.
Toshikazu Oki Akihiro Yoshimoto Tatsuo Ogasawara Seiji Sato Akira Takamatsu 《Archives of microbiology》1976,107(2):183-187
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
8.
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
9.
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
10.
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
11.
Rachel Galun 《Entomologia Experimentalis et Applicata》1989,50(2):133-139
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.
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
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
12.
Folkert Reck Matthias Springer Ernst Meinjohanns Hans Paulsen Inka Brockhausen Harry Schachter 《Glycoconjugate journal》1995,12(6):747-754
UDP-GlcNAc:Man1-3R 1-2-N-acetylglucosaminyltransferase I (GlcNAc-T I; EC 2.4.1.101) catalyses the conversion of [Man1-6(Man1-3)Man1-6][Man1-3]Man-O-R to [Man1-6(Man1-3)Man1-6] [GlcNAc1-2Man1-3]Man-O-R (R=1-4GlcNAc1-4GlcNAc-Asn-X) and thereby controls the conversion of oligomannose to complex and hybrid asparagine-linked glycans (N-glycans). GlcNAc-T I also catalyses the conversion of Man1-6(Man1-3)Man-O-octyl to Man1-6(GlcNAc1-2Man1-3)Man-O-octyl. We have therefore tested a series of synthetic analogues of Man1-6(Man1-3)Man-O-octyl as substrates and inhibitors for rat liver GlcNAc-T I. The 2-deoxy and the 3-, 4- and 6-O-methyl derivatives are all good substrates confirming previous observations that the hydroxyl groups of the Man1-6 residue do not play major roles in the binding of substrate to enzyme. In contrast, all four hydroxyl groups on the Man1-3 residue are essential since the corresponding deoxy derivatives either do not bind (2- and 3-deoxy) or bind very poorly (4- and 6-deoxy) to the enzyme. The 2- and 3-O-methyl derivatives also do not bind to the enzyme. However, the 4-O-methyl derivative is a substrate (K
m
=2.6mm) and the 6-O-methyl compound is a competitive inhibitor (K
i=0.76mm). We have therefore synthesized various 4- and 6-O-alkyl derivatives, some with reactive groups attached to anO-pentyl spacer, and tested these compounds as reversible and irreversible inhibitors of GlcNAc-T I. The 6-O-(5-iodoacetamido-pentyl) compound is a specific time dependent inhibitor of the enzyme. Four other 6-O-alkyl compounds showed competitive inhibition while the remaining compounds showed little or no binding indicating that the electronic properties of the attachedO-pentyl groups influence binding.Abbreviations GlcNAc-T I
UDP-GlcNAc:Man1-3R 1-2-N-acetylglucosaminyltransferase I (EC 2.4.1.101)
- GlcNAc-T II
UDP-GlcNAc:Man1-6R 1-2-N-acetylglucosaminyltransferase II (EC 2.4.1.143)
- MES
2-(N-morpholino)ethane sulfonic acid monohydrate 相似文献
13.
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
14.
Claudia P. Spampinato Piotr Paneth Marion H. O'Leary Carlos S. Andreo 《Photosynthesis research》1991,28(2):69-76
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
15.
Summary When an aqueous solution (pH 7.0) of deoxythymidine 5-phosphate, 4-amino-5-imidazolecarboxamide and cyanamide was dried and heated for 18 h at 60°C, P1, P2-dideoxythymidine 5-pyrophosphate (I) was formed in a 58% yield. Oligonucleotides were not detected in the reaction product. Under conditions employed in the above reaction, (I) was shown to be stable. In prebiotic polymerization reactions employing deoxythymidine 5-triphosphate as the polymerizing species, (I) could therefore function as a primer and minimize the formation of cyclic nucleotides.Abbreviations dT
deoxythymidine
- dTMP
deoxythymidine 5-phosphate
- dTppT
P1, P2-dideoxythymidine 5-pyrophosphate
- dTTP
deoxythymidine 5-triphosphate
- AICA
4-amino-5-imidazolecarboxamide 相似文献
16.
Summary
Physarum polycephalum microplasmodia exposed to 1.6×10–5 M cytochalasin A evidenced intracellular cytoplasmic condensation, slow contraction, and eventual breaks at discrete surface areas, within one hour. Other cytochalasins tested (CB or CD) did not substitute for CA. CA effects on plasmodia were not abolished by immediate washing or media replacement. In nutrient medium, CA plus ATP (375 M) produced within minutes herniation (blebbing) and plasmodial disruption. The order of addition of reagents was important; ATP added simultaneously with or prior to CA stimulated the phenomenon, whereas initial addition of CA resulted in no such dynamic response. Several other nucleotides (e.g., AMP, cAMP) could substitute for ATP; however, such changes were not observed with 5-adenylylimidodiphosphate. Blebbing was not abolished in the presence of 2,4-dinitrophenol. In minimal medium, it was best stimulated by simultaneous addition of Ca++ and Mg++. Preincubation of CA with L-cysteine or with -mercaptoethanol negates its individual or nucleotide-combined effects. Yet, 10–5 M ethacrynic acid, a sulfhydryl-reactive liposoluble drug, in the presence of ATP does not mimic the blebbing response. These observed effects, which take place at or near the plasmodial surface, presumably reflect acceleration of normal contractile processes inPhysarum.
Abbreviations CA
cytochalasin A
- CB
cytochalasin B
- CD
cytochalasin D
- AMP
adenosine 5-monophosphate
- ADP
adenosine 5-diphosphate
- ATP
adenosine 5-triphosphate
- di-butyryl-cAMP
di-butyryl-cyclic adenosine 35-monophosphate
- di-butyrylcGMP
di-butyryl-cyclic guanosine 35-monophasphate.
This work was supported by a grant (AI-11902) from the U.S. Public Health Service. 相似文献
17.
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
18.
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
19.
Adenosine 5-phosphosulfate sulfotransferase (APSSTase) was purified over 2700-fold to homogeneity from the thalli of the marine macroalgaPorphyra yezoensis Ueda (Rhodophyta), using a combination of ammonium sulfate precipitation, hydrophobic chromatography, anion-exchange chromatography and gel-filtration. The native Mr measured by gel-filtration was 350 000. The subunit Mr was estimated to be 43 000 by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. In addition, APSSTase had a relatively broad pH optimum of pH 9.0–9.8 with a peak at pH 9.5. The apparentK
m value for adenosine 5-phosphosulfate (APS) was 2.1 M, when dithiothreitol was acceptor substrate. 3-Phosphoadenosine 5-phosphosulfate and inosine 5-phosphosulfate could not substitute for APS as a sulfate donor. The enzyme utilized several organic thiols as acceptor substrates (artificial substrates): dithiothreitol (apparentK
m = 1.5 mM) and dithioerythritol (apparentK
m = 1.5 mM) gave the highest activity, and appreciable activity was also obtained usingl-glutathione (reduced form) which exhibited slight substrate inhibition (apparentK
m = 0.6 mM; the initial velocity was maximal at 3.0–4.0 mM). While APSSTase was markedly unstable in vitro: the half-life for activity loss at 25°C and pH 9.5 was about 8 min, the instability was decreased in the presence of a relatively high concentration of Na2SO4 or (NH4)2SO4, and in the presence of APS or its analogs (AMP and -methylene-APS). Most of the thiols, with the sole exception of glutathione, were found to inactivate APSSTase irreversibly. The thiol-mediated inactivation was completely inhibited by the high concentration of Na2SO4, and by the analogs of APS.Abbreviations APS
adenosine 5-phosphosulfate
- APSSTase
adenosine 5-phosphosulfate sulfotransferase
- -m-APS
-methylene-adenosine 5-phosphosulfate
- DTT
dithiothreitol
- IPS
inosine 5-phosphosulfate
- PAPS
3-phosphoadenosine 5-phosphosulfate
We wish to thank Mr. I. Kashiwase, Mr. Y. Endo and Mr. Y. Mimura, School of Fisheries Sciences, Kitasato University, for their technical assistance in this study. The research described in this paper was partly supported by the Kitasato Research Grant (H5-9 and H6-13 to N.K.). 相似文献
20.
Servé W. M. Kengen Judith J. Mosterd Rob L. H. Nelissen Jan T. Keltjens Chris van der Drift Godfried D. Vogels 《Archives of microbiology》1988,150(4):405-412
The enzymatic conversion of formaldehyde to CH3S-CoM in crude extracts of Methanobacterium thermoautotrophicum was used as a means to investigate the methyl-tetrahydromethanopterin: HS-CoM methyltransferase reaction. All components necessary for formaldehyde conversion were shown to be present in a soluble protein fraction. This soluble cell fraction still contained a major amount of corrinoids. Apart from tetrahydromethanopterin no other soluble cofactors were required for formaldehyde conversion. The dependence of the system on catalytic amounts of ATP was shown to be specific. Several nucleoside triphosphates or ADP were unable to substitute for ATP. Remarkably, various strong reducing systems, especially titanium(III)citrate could replace ATP to a large extent. The ATP-dependent formaldehyde conversion to CH3S-CoM was inhibited in the presence of nitrous oxide, detergents or 2,3-dialdehyde-ATP. The results support a role for a corrinoid protein in the methyl-tetrahydromethanopterin: HS-CoM methyltransferase reaction at which ATP is involved in the activation of this protein, probably in the conversion of inactive B12a or B12r to active B12s.Abbreviations HS-CoM
Coenzyme M, 2-mercaptoethanesulfonate
- CH3S-CoM
methylcoenzyme M, 2-(methylthio)ethanesulfonate
- H4MPT
5,6,7,8-tetrahydromethanopterin
- BES
2-bromoethanesulfonate
- BCE
boiled cell-free extract
- DTT
dithiothreitol
- TCS
3,3,4,5-tetrachlorosalicylanilide
- DNTB
2,2-dinitro-5,5-dithiobenzoic acid
- TES
N-tris(hydroxymethyl)methyl-2-aminoethanesulfonate
- HEPES
N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid
- PIPES
piperazine-N,N-bis[2-ethanesulfonic acid]
- AMP-PNP
5-adenylyl imidophosphate 相似文献