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1.
Partial purification of myosin from lily pollen tubes by monitoring with in vitro motility assay 总被引:1,自引:0,他引:1
Summary Myosin in pollen tubes ofLilium longiflorum was partially purified, using an in vitro motility assay as a monitor. The main components in the partially purified preparation had molecular masses of 110, 120, and 140 kDa in SDS-PAGE. They became bound to actin filaments in an ATP-dependent manner. Among the components, only that of 120 kDa became bound to ATP and was concluded to be the heavy chain of pollen tube myosin.Abbreviations ATP
adenosine-5-triphosphate
- DTT
dithiothreitol
- EB
extraction buffer
- EGTA
ethyleneglycol-bis-(-aminoethylether) N, N, N, N-tetraacetic acid
- PAGE
polyacrylamide gel electrophoresis
- PIPES
piperazine-N,N-bis-(2-ethanesulfonic acid)
- PMSF
phenylmethylsulfonyl fluoride
- SDS
sodium dodecylsulfate
- TBS
Tris buffered saline
- TEB
Tris-EGTA buffer 相似文献
2.
Andrea Menédez Yuffá Eva G. de García Magdalena Segura Nieto 《Plant cell reports》1994,13(3-4):197-202
Embryogenic and non-embryogenic calli from leaf sections of Coffea arabica cv. Catimor, were analyzed under denaturing conditions in one- and two-dimensions by polyacrylamide gel electrophoresis. The protein patterns revealed qualitative and quantitative differences in size and charge. In non-embryogenic calli, two dimensional analysis reveals seven distinctive polypeptides in the range of 15 to 70 kDa. Four of the polypeptides are acidic, three of 70 kDa and one of 15 kDa. Similarly, in embryogenic calli there are seven characteristic polypeptides with molecular weight from 23 to 35 kDa in a broad pI from acid to basic. Five of them are found in the neutral to acid pI, and are probably related to storage protein-like polypeptides detected in zygotic embryos and seeds of Coffea arabica cv. Catimor. Changes in the protein pattern appear to correlate with histological differences in embryogenic calli and with different stages of development of somatic embryos.Abbreviations SDS-PAGE
Sodium dodecyl sulfate polyacrylamide gel electrophoresis
- NEpHGE
non-equilibrium pH gradient electrophoresis
- TEMED
N,N,N,N-tetramethylethylenediamine
- 1D
one dimensional gel electrophoresis
- 2D
two-dimensional gel electrophoresis
- EGTA
ethylene glycol-bis(-aminoethyl ether) N,N,N,N-tetraacetic acid
- PVP
polyvinylpyrrolidone
- ME
2-mercaptoethanol
- PMSF
phenylmethylsulfonyl fluoride
- NAA
naphtaleneacetic acid
- 2,4-D
2,4-dichlorophenoxyacetic acid
- BA
benzyladenine 相似文献
3.
Summary We have studied a number of condensation reactions involving ImpU, ImpT, ImpC, ImpA, ImpG, ImpUpG and ImpCpA as activated nucleotide donors and a variety of homo- and hetero-polynucleotides as templates. We did not obtain any evidence of a template effect with ImpU and ImpT, but observed some condensation of ImpC with GpG on appropriate templates. ImpA and ImpG take part in a number of more or less efficient template-directed reactions, as do ImpUpG and ImpCpA.Our results suggest that, on the primitive Earth, pyrimidine nucleotides could most easily have been incorporated into polymers as constituents of short oligomers, which contained one or more purine nucleotide. The linkage of the product depends strongly on the nature of the substrates; the percentage of the natural 3-5-linkage was, in some cases, less than 10% and, in others, as high as 70%. Wobble-pairing was often very effective in promoting condensations, suggesting that transition mutations would have been very frequent in prebiotic polynucleotide replication.Abbreviations and Conventions U
uridine
- T
thymidine
- C
cytidine
- A
adenosine
- G
guanosine
- pN
nucleoside-5-phosphate
- Np
a mixture of 2- and 3-phosphates of a nucleoside
- pNp
a mixture of the 2-5-diphosphate and 3-5-diphosphate of a nucleoside
- N1
2 pN2
a 2-5-linked dinucleoside monophosphate
- N1
3 pN2
a 3-5-linked dinucleoside monophosphate
- N5 ppN
a pyrophosphate derived from a nucleoside-5-phosphate. ImpN and ImpN1pN2 are 5-phosphorimidazolides of nucleosides and 3-5-linked dinucleoside monophosphates, respectively
- poly(N)
a homopolynucleotide
- poly (U1 C2 A4 G3)
a random copolymer derived from a substrate mixture containing U, C, A, G in ratio 1:2:4:3
- ODU
optical density units measured at 260 nm 相似文献
4.
The rate of CO2- and p-benzoquione-dependent photosynthetic O2 evolution by Anabaena variabilis cells remained unaltered and the rate of O2 uptake observed after switching off the light (endogenous respiration) was enhanced by a factor of 6–8 when the O2 concentration was increased from 200 to 400 M. Photosystem-I-linked O2 uptake and respiration of the cells incubated with ascorbate and N,N,NN-tetramethyl-p-phenylenediamine was not appreciable influenced by the O2 concentration. 2-Iodo-6-isopropyl-3-methyl-2,4,4-trinitrodiphenyl ether, blocking electron transfer at the plastoquinone level, suppressed O2 evolution and had no influence on endogenous respiration. 2-n-Heptyl-4-hydroxyquinoline-N-oxide, an inhibitor of electron transfer between photosystems II and I, as well as the cytochrome-oxidase inhibitors N
3
-
, CN- and NH2OH, caused a 35–50% retardation of endogenous respiration and blocked photosynthetic O2 evolution. The molar ratio of cytochromes b6, f, c-553, aa3 and photosystem-I reaction centers in the isolated membranes equalled approx. 2:1:2:0.7:2. It is inferred that endogenous respiration of A. variabilis cells is inhibited by the light-induced electron flow through both photosystems at the level of the plastoquinone-plastocyanin-oxidoreductase complex.Abbreviations DCMU
3-(3,4-dichlorophenyl)-1,1-dimethylurea
- DNP-INT
2-iodo-6-isopropyl-3-methyl-2,4,4-trinitrodiphenyl ether
- Hepes
4-(2-hydroxyethyl)-1-piperazine ethansulfonic acid
- TMPD
N,N,NN-tetramethyl-p-phenylenediamine 相似文献
5.
Assunta Baccarini-Melandri B. Andrea Melandri Günter Hauska 《Journal of bioenergetics and biomembranes》1979,11(1-2):1-16
(1) Inhibition of cyclic phosphorylation in chromatophores ofRhodopseudomonas capsulata by antimycin A can be fully reversed by artificial redox mediators, provided the ambient redox potential is maintained around 200 mV. The redox mediator need not be a hydrogen carrier in its reduced form, N-methyl-phenazonium methosulfate and N,N,N,N-tetramethyl-p-phenylenediamine being equally effective. However, the mediator needs to be lipophilic. Endogenous cyclic phosphorylation is fastest around 130 mV. A shift to 200 mV can also be observed if high concentrations of artificial redox mediator are present in the absence of antimycin A. (2) ATPase activity ofRhodopseudomonas capsulata, in the light as well as in the dark, activated or not activated by inorganic phosphate, can also be stimulated by N-methylphenazonium methosulfate. This stimulation is highest at redox potentials between 60 to 80 mV and is sensitive to antimycin A. In this case N,N,N,N-tetramethyl-p-phenylenediamine is much less effective.Abbreviations PES
N-methyl-phenazonium ethosulfate
- PMS
N-methyl-phenazonium methosulfate
- TMPD
N,N,N,N-tetramethyl-p-phenylenediamine
- DAD
diaminodurene (2,3,5,6-tetramethyl-p-phenylenediamine)
- Bchl
bacteriochlorophyll
- FCCP
carbonylcyanide-p-trifluoromethoxy-phenylhydrazone
-
E
h
redox potential
-
E
m
midpoint redox potential 相似文献
6.
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
7.
The effects of solar and artifical ultraviolet radiation on the marine cryptoflagellate, Cryptomonas maculata, were studied. Even after short exposure to UV the accessory photosynthetic pigment phycoerythrin is bleached; likewise the fluorescence undergoes significant changes both in amplitude and in the maximal peak wavelength. In parallel, the photosynthetic oxygen production decreases rapidly during exposure. Gel electrophoresis and FPLC of membrane proteins show a significant decrease in chromoproteins after 2 h UV, which is confirmed by fluorescence excitation and emission spectra of the FPLC fractions.Abbreviations APS
ammonium persulfate
- DCMU
3-(3,4dichlorophenyl)1,1-dimethylurea; Emulphogen, polyoxyethylene 10 tridecyl ether
- FPLC
fast protein liquid chromatography
- PMSF
phenylmethylsulfonyl fluoride
- SDS
sodium dodecylsulfate
- SDS PAGE
sodium dodecylsulfate polyacrylamide gel electrophoresis
- TEMED
NN NNtetramethylethylene diamine
- UV-A
wavelength range between 320 nm and 400 nm
- UV-B
wavelength range between 280 nm and 320 nm
Dedicated to the 60th birthday of Professor Dr. W. Wehrmeyer 相似文献
8.
Summary In pollen tubes, the motive force of cytoplasmic streaming is assumed to be generated by the sliding of the translocator associated with cell organelles along actin filaments. In the present study, the characteristics of the translocator were studied by reconstituting the movement of pollen tube organelles along characean actin bundles. Movement of pollen tube organelles proceeded from the pointed end to the barbed end of the actin filaments of the characean cells. The reconstituted movement was not inhibited by vanadate. KCL at higher concentrations inhibited the movement. Furthermore, heavy meromyosin (HMM) prepared from rabbit skeletal muscle myosin partially inhibited the reconstituted movement and pCMB-modified HMM inhibited it completely. The present results strongly support our previous conclusion that the translocator which generates the motive force of cytoplasmic streaming in pollen tube is myosin.Abbreviations AMP-PNP
adenylyl-imidodiphosphate
- ATP
adenosine-5-triphosphate
- ATP--S
adenosine-5-0-(3-thiotriphosphate)
- BSA
bovine serum albumin
- CCCP
carbonylcyanide m-chlorophenylhydrazone
- DTT
dithiothreitol
- EDTA
ethylenediamine tetraacetic acid
- EGTA
ethyleneglycol-bis-(-aminoethyl ether)N,N,N,N-tetraacetic acid
- HB
homogenization buffer
- HMM
heavy meromyosin
- NEM
N-ethylmaleimide
- pCMB
p-chloromercuribenzoic acid
- PIPES
piperazine-N,N-bis-(2-ethanesulfonic acid)
- PPi
pyrophosphate 相似文献
9.
Boscariol RL Almeida WA Derbyshire MT Mourão Filho FA Mendes BM 《Plant cell reports》2003,22(2):122-128
A new method for obtaining transgenic sweet orange plants was developed in which positive selection (Positech) based on the Escherichia coli
phosphomannose-isomerase (PMI) gene as the selectable marker gene and mannose as the selective agent was used. Epicotyl segments from in vitro-germinated plants of Valencia, Hamlin, Natal and Pera sweet oranges were inoculated with Agrobacterium tumefaciens
EHA101-pNOV2116 and subsequently selected on medium supplemented with different concentrations of mannose or with a combination of mannose and sucrose as a carbon source. Genetic transformation was confirmed by PCR and Southern blot. The transgene expression was evaluated using a chlorophenol red assay and isoenzymes. The transformation efficiency rate ranged from 3% to 23.8%, depending on cultivar. This system provides an efficient manner for selecting transgenic sweet orange plants without using antibiotics or herbicides.Abbreviations BAP
Benzylaminopurine
- CPR
Chlorophenol red
- EGTA
Ethylene glycol-0-0- bis (2, aminoethyl) N, N, N, N tetraacetic acid
- MTT
[3-(4,5-Dimethyl thiazol-2-YL)-2,5-diphenyl] tetrazolium bromide
- PMI
Phosphomannose isomerase (EC 5.3.1.8)
- PMS
Phenazine methosulphate
Communicated by L. Peña 相似文献
10.
Z. Krupa 《Photosynthesis research》1982,3(2):95-104
Bean chloroplasts treated with galactolipase (lipolytic acyl hydrolase) isolated from bean leaves showed an inhibition of photosystem I activity as measured by methyl viologen-mediated oxygen uptake and NADP+ photoreduction. This inhibition was partially reversed by exogenous plastocyanin added to galactolipase-treated thylakoid membranes. Galactolipase released substantial amounts of endogenous plastocyanin (about 40%) from bean chloroplasts. The results are discussed with regard to the localization of plastocyanin in thylakoid membranes.Abbreviations chlf
chlorophyll
- DCMU
3-(2,4-dichlorophenyl)-1,1-dimethylurea
- DGDG
digalactosyldiacylglycerol
- MGDG
monogalactosyldiacylglycerol
- MV
methyl viologen
- NADP+
nicotinamide dinucleotide phosphate
- PC
phosphatidylcholine
- PG
phosphatidylglycerol
- PE
phosphatidylethanolamine
- PI
phosphatidylinositol
- SQDG
sulphoquinovosyldiacylglycerol
- SDS
sodium dodecyl sulphate
- TMPD
N,N,N,N-tetramethyl-p-phenylenediamine
- Tricine
N-Tris-(hydroxymethyl)-methylglycine
- Tris
Tris-(hydroxymethyl)-aminomethane 相似文献
11.
ATPase activity in rat heart sarcoplasmic reticulum was stimulated in a concentration-dependent manner by both Ca2+ and Mg2+ in the complete absence of the other cation. Increasing concentrations of Mg2+ produced an apparent inhibition of the Ca2+-dependent ATP hydrolysis. CDTA (trans-1,2-diaminocyclohexane-N,N,N,N-tetraacetate) had no effect on these responses. The results indicate the presence of a low affinity non-specific divalent cation-stimulated ATPase in rat heart sarcoplasmic reticulum. However, sarcoplasmic reticulum vesicles transported Ca2+ with a high affinity (K0.5 Ca2+ = 0.41 M) suggesting the presence of a high affinity Ca2+-transporting ATPase. Calmodulin did not stimulate rat heart sarcoplasmic reticulum ATPase activity over a range of Ca2+ and Mg2+ concentrations and failed to stimulate membrane phosphorylation and Ca2+ transport into sarcoplasmic reticulum vesicles. Calmodulin antagonists trifluoperazine and compound 48180 did not affect the ATPase activity. Catalytic subunit of cAMP-dependent protein kinase was also ineffective in stimulating the ATPase activity. These results suggest the presence of an ATPase activity in rat heart sarcoplasmic reticulum with different properties from the high affinity Ca2+-pumping ATPase previously characterized in dog heart and other species.Abbreviations cAMP
adenosine 3,5-monophosphate
- CaM
calmodulin
- CDTA
trans-1,2-diaminocyclohexane-N,N,N,N-tetraacetate
- EDTA
ethylene-diaminetetraacetate
- EGTA
ethylene glycol bis(-aminoethyl ether)-N,N,N,N-tetraacetate
- PLB
phospholamban
- SR
sarcoplasmic reticulum
- TFP
trifluoperazine 相似文献
12.
Maria Mulisch 《Protoplasma》1988,143(2-3):170-175
Summary Different fixation techniques were employed to obtain satisfactory fixation of the endoplasm ofStentor coeruleus for ultrastructural investigations. The nuclei ofS. coeruleus are surrounded by a flattened fenestrated cisterna. The space between the nuclear envelope and the cisterna (= perinuclear space) is continuous with the cytoplasm via channels. The envelopes of both, micronucleus and macronucleus, are connected to the fenestrated cisterna by filamentous material. This organization accounts for the close association between micronucleus and macronucleus inStentor coeruleus. The fenestrated cisterna is compared to similar structures occurring in other organisms, and its possible function is discussed.Abbreviations fC
fenestrated cisterna
- FV
food vacuole
- km
km fibers
- MaNu
macronucleus
- MiNu
micronucleus
- My
myonome
- NE
nuclear envelope
- PC
perinuclear cisterna
- PfC
pore of fenestrated cisterna
- PS
perinuclear cytoplasmic space
- EGTA
ethyleneglycol-bis-(-aminoethylether)-N,N,N,N-tetraacetic acid)
- GA
glutaraldehyde
- HEPES
N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid
- PEG
polyethylene glycol
- PIPES
piperazine-N,N-bis[2-ethanesulfonic acid]
- PTA
phosphotungstic acid 相似文献
13.
The plant pathogen Nectria haematococca can demethylate pisatin, a phytoalexin from pea. Demethylation is apparently necessary for virulence on pea and is catalyzed by a microsomal cytochrome P-450 monooxygenase system. The cytochrome P-450 and NADPH-cytochrome P-450 reductase of this system were solubilized with sodium cholate and partially purified by chromatography on blue A-agarose and -aminohexyl-agarose. The reductase was further purified by chromatography on 2,5-ADP-agarose to a specific activity of about 16 moles cytochrome c reduced per min per mg protein. Upon sodium dodecyl sulfatepolyacrylamide gel electrophoresis, the reductase fraction contained one major band of molecular weight 84,000. The partially purified cytochrome P-450 fraction contained a number of minor bands and three major bands of molecular weights 52,000, 56,000 and 58,000. This fraction lost all demethylase activity during concentration after -aminohexyl-agarose chromatography, so it could not be purified further. The purified reductase could reconstitute demethylase activity of cytochrome P-450 fractions and appeared to be rate-limiting for demethylase activity in microsomal extracts. 相似文献
14.
Takenori Miyamoto Diego Restrepo Edward J. Cragoe Jr. John H. Teeter 《The Journal of membrane biology》1992,127(3):173-183
Summary Olfactory receptor neurons enzymatically dissociated from channel catfish olfactory epithelium were depolarized transiently following dialysis of IP3 or cAMP (added to the patch pipette) into the cytoplasm. Voltage and current responses to IP3 were blocked by ruthenium red, a blocker of an IP3-gated Ca2+-release channel in sarcoplasmic reticulum. In contrast, the responses to cAMP were not blocked by extracellularly applied ruthenium red, nor by l-cis-diltiazem or amiloride and two of its derivatives. The current elicited by cytoplasmic IP3 in neurons under voltage clamp displayed a voltage dependence different from that of the cAMP response which showed marked outward rectification. A sustained depolarization was caused by increased cytoplasmic IP3 or cAMP when the buffering capacity for Ca2+ of the pipette solution was increased, when extracellular Ca2+ was removed or after addition of 20–200 nm charibdotoxin to the bathing solution, indicating that the repolarization was caused by an increase in [Ca
i
] that opened Ca2+-activated K+ channels. The results suggest that different conductances modulated by either IP3 or cAMP are involved in mediating olfactory transduction in catfish olfactory receptor neurons and that Ca2+-activated K+ channels contribute to the termination of the IP3 and cAMP responses.Abbreviations ATP
adenosine 5-triphosphate
- BAPTA
(bis-(o-aminophenoxy)-ethane-N-N-N-N)-tetraacetic acid
- cAMP
adenosine cyclic 3,5-monophosphate
- cGMP
guanosine cyclic 3,5-monophosphate
- CTX
charybdotoxin
- DCB
3,4-dichlorobenzamil
- EDTA
ethylenediaminetetraacetic acid
- EGTA
ethylenglycol-bis-(b-aminoethyl)-N-N-N-N-tetraacetic acid
- HEPES
N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid
- IP3
inositol-1,4,5-triphosphate
- NMDG
N-methyl-d-glucamine
We would like to thank the Tanabe Seiyaku Co., Ltd., for their gift of l-cis-diltiazem. This work was supported by National Institutes of Health grants DC00566 and BRSG S07RR05825. 相似文献
15.
Kuang Yu Chen 《Molecular and cellular biochemistry》1984,58(1-2):91-97
Summary Transglutaminase, purified from guinea pig liver, was used to catalyze the incorporation of [14C]putrescine into exposed surface proteins of intact mouse neuroblastoma cells. This method specifically labeled two surface proteins (Mr = 92 000 and 76 000) in the N-18 mouse neuroblastoma cells and three surface proteins (Mr = 92 000, 76 000, and 72 000) in the NB-15 mouse neuroblastoma cells. In addition, transglutaminase also catalyzed cross-linking reactions of exposed surface proteins. In both the N-18 and NB-15 cells, differentiation was accompanied by a 2-fold increase of specific radioactivity incorporated into trichloroacetic acid insoluble cellular material, suggesting that the differentiated mouse neuroblastoma cells may possess greater amount of accessible peptide-bound glutaminyl residues on their surface than their malignant counterparts. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorographic method revealed that while the [14C]putrescine-labeled protein patterns of undifferentiated and differentiated mouse neuroblastoma cells were similar, the intensity of labeling of individual bands was specifically modulated by cell differentiation.Abbreviations PMSF
phenylmethylsulfonylfluoride
- Bt2cAMP,N6,O2
Dibutyryl adenosine 3:5-cyclic monophosphate
- IBMX
3-isobutyl-l-methyl xanthine
- SDSPAGE
sodiumdodecylsulfate-polyacrylamide gel electrophoresis
- HEPES
N-2-hydroxylethylpiperazine-N-2-ethanesulfonic acid 相似文献
16.
Chromatium vinosum cells form a vesicular type intracytoplasmic membrane system during phototrophic growth on thiosulfate.—An enzyme protein transferring electrons from thiosulfate to cytochromes of type c was enriched from S-144. The colorless thiosulfate: cytochrome c oxidoreductase was characterized by a molecular weight of 36,000 (after dodecylsulfate treatment) and 35,000 (by gel filtration). Isoelectric focusing revealed a pI range of 4.4 to 4.7. Apparent K
m values for the cytochromes tested were in the M range. — The endogenous electron acceptor compound, isolated from the chromatophore fraction P-144, was found to be a membrane-bound cytochrome c-552. The homogeneous cytochrome protein had an average pI value of 4.65 and a molecular weight of 71,500 determined by gel filtration. By dodecylsulfate electrophoresis it was cleaved into two proteins representing particle weights of 45,000 and 20,000.Abbreviations HiPIP
high potential nonheme iron protein
- IEF
isoelectric focusing
- SDS
dodecylsulfate, sodium salt
- Temed
N,N,N,N-tetramethylethylenediamine 相似文献
17.
Summary The active sites of actin of oneCharaceae species were found to interact with the endoplasmic factor from a different species. Protoplasm was suqueezed out of cells ofChara australis with vacuoles that had been perfused beforehand with a medium containing EGTA and Mg · ATP. Centrifugation of this protoplasmic mixture divided it into the supernatant composed of endoplasmic granules and the precipitate composed of chloroplasts and nuclei. When the endoplasmic granular aggregates were introduced into a tonoplast-freeNitella axilliformis cell treated with NEM to inactivate the endoplasmic factor, they became attached to theNitella gel and streamed longitudinally with the polarity. Treatment of the endoplasmic granules with the strong Mg2+chelator CyDTA (1,2-cyclohexane diamineN, N-tetraacetic acid) irreversibly inhibited reconstitution of the cytoplasmic streaming.Abbreviations APW
artificial pond water
- ATP
adenosine-5-triphosphoric acid
- CyDTA
cyclohexanediamine-N,N-tetraacetic acid
- DTT
dithiothreitol
- EGTA
ethyleneglycol-bis-(-aminoethylether)-N,N-tetraacetic acid
- HMM
heavy meromyosin
- NEM
N-ethylmaleimide
- PEP
phosphoenolypyruvate
- PIPES
piperazine-N,N-bis-(2-ethane-sulfonic acid)
- PK
pyruvate kinase
- PMSF
phenylmethylsulfonylfluoride 相似文献
18.
S. Biagionia G. Scarsella L. Settimi M. E. Traina 《Molecular and cellular biochemistry》1982,43(3):183-190
Summary Inhibition of growth of PY815 mouse mastocytoma cells in vitro by N6, O2-dibutyryladenosine 3,5 cyclic monophosphate (DB cyclic AMP) was accompanied by increases in intracellular cyclic AMP and histamine and minor changes in cytosolic cyclic AMP-dependent histone kinase activity. However, DEAE-cellulose chromatography revealed substantial changes in the relative proportions of the principal cyclic AMP-dependent protein kinases and in free cyclic AMP-binding protein after DB cyclic AMP treatment. The activity of cytosolic cyclic AMP-dependent protein kinase type I (PKI) decreased relative to cyclic AMP-dependent protein kinase type II (PKII) and there was an increase in a cytosol cyclic AMP-binding protein with little associated protein kinase activity. The relative changes in activity of PKI, PKII and cyclic AMP binding protein after DB cyclic AMP treatment may reflect events important in the regulation of growth and differentiation of mast cells.Abbreviations DB cyclic AMP
N6,O2-dibutyryladenosine-3, 5-cyclic monophosphate
- cyclic AMP
adenosine 3,5-cyclic monophosphate
- PKI
type I cyclic AMP-dependent protein kinase
- PKII
type II cyclic AMP-dependent protein kinase 相似文献
19.
Fabián Atlasovich José A. Santomé Horacio N. Fernández 《Molecular and cellular biochemistry》1993,120(1):15-23
Summary Photoreactive probes for the hydrophobic pocket of the liver fatty acid-binding protein, 11-(5-azido-salicylamido)-undecanoic acid (5 ASU) and its acetyl ester (Ac5 ASU), were synthesized and their interaction with the protein was assessed. Fatty acid-binding proteins are closely related proteins which are abundantly expressed in tissues with active lipid metabolism. A simple model that assumes that the protein possesses a single kind of sites fitted the binding of radioiodinated 5 ASU to L-FABP satisfactorily. The apparent dissociation constant, 1.34×10–7 M, evidenced a slightly higher affinity than that reported for C16–C20 fatty acids. Consistent with the binding curve, 5 ASU effectively competed with palmitic acid for the hydrophobic sites and the effect was nearly complete for concentrations of 1 gmM; oleic acid, in turn, displaced the radiolabelled probe. Irradiation at 366 nm of125I-5 ASU bound to L-FABP caused the covalent cross-linking of the reagent. The amount of radioactivity covalently bound reached a maximum after 2 min thus agreeing with the photo-activation kinetics of the unlabelled compound that evidenced a t1/2 of 31.1 sec. The yield with which probes bound to L-FABP became covalently linked to the protein, appraised after SDS-PAGE of irradiated samples, was estimated as 23 and 26 per cent for 5 ASU and Ac5 ASU respectively. In turn, irradiation of L-FABP incubated with 5ASU or Ac5 ASU resulted in the irreversible loss of about one fourth its ability to bind palmitic acid. Both results, taken together, suggested that the derivatives are linked to the protein through the sites for fatty acids. When cross-linking of125I-5 ASU was performed after incubation with delipidated cytosol and products were analyzed by SDS-PAGE, a band was visualized in a position similar to that of purified L-FABP.Abbreviations FABP
Fatty Acid-Binding Protein
- L-FABP
Hepatic FABP
- I-FABP
Intestinal FABP
- C-FABP
Cardiac FABP
- 5 ASU-11
(5-azido-salicylamido)-undecanoic acid
- Ac5 ASU-11
(O-acetyl-5-azido-salicylamido)-undecanoic acid 相似文献
20.
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