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1.
  • 1.1. One adult male, eight pups (including two full term foetuses) and nine adult female harbour seals (Phoca vitulina) were analysed for indices of mixed function oxidase (MFO) activity.
  • 2.2. MFO activity was present in liver samples, but was at or below detection limits in samples of kidney, lung and pancreas.
  • 3.3. Hepatic ethoxyresorufin O-de-ethylase and benzo[a]pyrene hydroxylase activities were similar to those reported in other seals and in other mammals.
  • 4.4. Cytochromes P-450 and b5 concentrations were slightly lower than those observed in other mammals.
  • 5.5. MFO activities in newborn pups and foetuses were significantly lower than those in adult females.
  • 6.6. No qualitative differences in cytochrome P-450 isozyme distribution between foetal and adult samples could be discerned by electrophoresis.
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2.
  • 1.1. Seven natural populations of Dacus dorsalis were analyzed for a dimeric esterase by means of horizontal starch-gel electrophoresis.
  • 2.2. The electrophoretic phenotypes were governed by nine codominant Est-D alleles.
  • 3.3. The commonest allele in all seven population samples was Est-D100 which encoded an electrophoretic band with intermediate mobility.
  • 4.4. The distribution of EST-D phenotypes were in accordance with Hardy-Weinberg expectations.
  • 5.5. There was no geographic variation in the distribution of Est-D alleles.
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3.
  • 1.1. The activities of S-adenosylmethionine decarboxylase (EC 4.1.1.50) were measured in cell extracts of mantle, hepatopancreas and foot from Mytilus edulis.
  • 2.2. The apparent molecular weights of the enzymes estimated by gel filtration chromatography were 65,000 ± 10,000.
  • 3.3. The enzymes do not require bivalent cations for catalysis and show optimum pH between 7.0–8.0 in phosphate buffer.
  • 4.4. The hepatopancreas enzyme shows different behavior to the other two enzymes against temperature and its activity is strongly inhibited by NH4+.
  • 5.5. The apparent Kms for S-adenosylmethionine were found to be 300, 200 and 250 μM for the hepatopancreas, mantle and foot enzymes, respectively.
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4.
  • 1.1. The protein composition of Bothrops jararaca venom and venom gland was analyzed through SDS-PAGE, after isoproterenol (IPR) treatment.
  • 2.2. Some proteins (47, 48, 57 and 72 kDa) were detected in the gland homogenate from the control but not from the IPR-treated samples.
  • 3.3. Three proteins (26.5, 44.5 and 53 kDa) were detected in the venom gland from IPR-treated snakes but not from the venom gland from the control.
  • 4.4. In the venom samples proteins of 41 and 74 kDa were detected only in the IPR treated samples, while proteins of 17 and 28 kDa were detected only in the control.
  • 5.5. The biological activity of the venom did not change with IPR treatment.
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5.
  • 1.1. Nematocyst structural proteins (NSP) from the sea anemones Aiptasia pallida and Metridium senile and the siphonophore Physalia physalis are primarily low molecular weight collagens linked by disulfide bonds.
  • 2.2. NSP patterns resolved by SDS-PAGE revealed a common, major collagen species (40 kDa) in each nematocyst type, together with other collagens and non-thiol-containing proteins.
  • 3.3. For each cnidarian, NSP glycosylation profiles were significantly different.
  • 4.4. Monoclonal antibodies against Aiptasia NSP demonstrated a differential distribution between capsule wall and thread.
  • 5.5. NSP differences would account for the diversity of morphologic and functional types.
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6.
  • 1.1. Co-isolating proteins (Mr 170,000–220,000) from sodium channel preparations made from the electric organ of the electric eel (Electrophorus electricus) were detected on Western blots using monoclonal a antibodies.
  • 2.2. Similar protein patterns were seen on immunoblots containing immunoprecipitated protein from eel muscle and brain tissues but not heart.
  • 3.3. These co-isolating proteins could be separated from the mature TTX-sensitive channel protein (Mr 280,000) using a lentil lectin-Sepharose column.
  • 4.4. The 180 kDa proteins do not appear to be channel-related and can be detected as contaminants in electroplax sodium channel preparations using the monoclonal antibodies described here.
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7.
  • 1.1. Muscle esterase variation in Sceloporus jarrovi, sampled from 25 locations in southeastern Arizona, was investigated employing acrylamide gel electrophoresis.
  • 2.2. Three distinct esterase phenotypes were observed, presumably resulting from the expression of two gene loci, Est-1 and Est-2.
  • 3.3. Lizards sampled from all 25 locations were found to be monomorphic with respect to esterase encoded at Est-1. Further, lizards sampled from the Santa Rita and Pinaleno Mountains were also found to be monomorphic for esterases encoded at Est-2, whereas those sampled from the Chiricahua and Huachuca Mountains proved to be polymorphic.
  • 4.4. Characterization of the esterases utilizing eserine sulfate, diisopropylfluorophosphate, and sulfhydryl-group inhibitors revealed the EST-1 isozyme to be an arylesterase and the EST-2 isozymes to be carboxylesterases.
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8.
  • 1.1. Elastase has been purified from the hepatopancreas of the king crab (Paralithodes camtschatica). Specific activity of the enzyme measured toward Suc-(Ala)3-pNA and Boc-(Ala)3-pNA was 926 and 3700 mUnits per mg of protein, respectively.
  • 2.2. The enzyme is an anion protein (pI 4.5) with an approximate mol.wt of 28.5 kDa.
  • 3.3. The enzyme exhibited a bell-shaped pH-dependence for the hydrolysis of Suc-(Ala)3-pNA with a maximum at 8–8.5. Under these conditions the values of Km and kcat of the crab elastase are 4 mM and 4.75 s−1, respectively.
  • 4.4. The serine elastase is effectively inhibited by elastinal and diisopropylfluorophosphate.
  • 5.5. It is shown that some salts except HgCl2 activate the protease. In the presence of HgCl2 with concentrations of 10 mM and higher, the crab elastase is inactive. SDS and Triton X-100 have no any effect on the activity of crab elastase.
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9.
  • 1.1. A membrane fragment of complex I from the fungus Neurospora crassa was isolated by immunoprecipitation from alkaline-extracted mitochondrial membranes.
  • 2.2. Analysis of the polypeptide composition of this hydrophobic domain of complex I has brought insights on the topology of two subunits of the enzyme, namely the 20.8 and 9.3 kDa components.
  • 3.3. Our results indicate that the ubiquinone-binding site of complex I resides in the interface of the peripheral and membrane arms of the enzymes. The significance of these findings are discussed.
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10.
  • 1.1. Optimum in vitro conditions, and kinetics of the enzyme catechol-O-methyltransferase from the brain of the male African catfish were studied.
  • 2.2. A saturated level for S-adenosylmethionine, as methyldonor, and magnesium as cofactor was reached at 5 μM and 10 mM, respectively.
  • 3.3. The addition of ascorbic acid, as an antioxidant, and tranylcypromine, as a MAO inhibitor, was not necessary, during incubations with fore-brain homogenates.
  • 4.4. Kinetic analysis of the methylation of catecholestrone, catecholestradiol and dopamine showed Km values of 1.2, 0.6 and 0.5 μM, respectively.
  • 5.5. The affinity of the catecholsubstrates for the enzyme catechol-O-methyltransferase is much higher in the brain of the African catfish than in tissues of mammals.
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11.
  • 1.1. To understand the physiological roles of the 90-kDa stress protein (HSP90), we investigated the heparin- and antibody-binding domains of the protein.
  • 2.2. For heparin-binding sites, HSP90 was digested completely with trypsin, and the digests were applied to a heparin-Sepharose column and eluted with 1.0 M NaCl, followed by 8.0 M urea.
  • 3.3. Each elutant was purified by a reverse-phase C18 column.
  • 4.4. Two peptides from the NaCl-eluted fraction and no peptide from the urea-eluted fraction were purified.
  • 5.5. The purified peptides were sequenced by an automated peptide sequencer.
  • 6.6. One of the heparin-binding sites was present between Leu-362 and Arg-365; another was present between Leu-645 and Lys-648.
  • 7.7. These two peptides were basic and considerably hydrophilic.
  • 8.8. For antibody-binding sites, HSP90 was mildly digested with trypsin, electrophoresed on SDS-polyacrylamide gels and transferred to PVDF membranes.
  • 9.9. The four bound of the trypsin fragments could be sequenced with a peptide sequencer.
  • 10.10. There was only one antibody-binding peptide, 38 kDa, starting from Pro-2. The others showed no cross-reactivity with the antibody and started from Leu-283.
  • 11.11. Therefore, the epitopes of HSP90 are present between Pro-2 and Leu-282.
  • 12.12. The heparin-binding sites are present from the middle region of the HSP90 molecule, and the antigen sites are at the N-terminal domain.
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12.
  • 1.1. Fundamental chitin digestion characteristics of Crassostrea virginica crystalline style were investigated.
  • 2.2. Optimum temperature and pH were 34°C and 4.8. respectively.
  • 3.3. The colloidal regenerated chitin (0.56mol/0.5 ml: GlcNAc equivalents) was saturating under all enzyme levels encountered.
  • 4.4. There was no evidence of end product inhibition, even after 100 hr incubation.
  • 5.5. Calculated Km for the chitinase complex was 1.19mM when determined using a 30 min assay, but was only 0.70 mM when determined using a 4.6 hr assay.
  • 6.6. Both Km values are lower than reported for similar assays in other molluscs and for most bacteria.
  • 7.7. Effect of substrate preparation on the kinetics are discussed.
  • 8.8. Eight peaks of chitinase activity were resolved by DEAE-Fractogel ion exchange chromatography.
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13.
  • 1.1. Adenylylation, a posttranslational modification of proteins, was investigated in saponin-permeabilized acinar cells of the rat parotid gland.
  • 2.2. When cells were incubated with [2,8-3H]ATP, several proteins, including a 26 kDa protein in the particulate fraction, were labeled.
  • 3.3. Upon incubation of cells with [α-32P]ATP in the presence of cAMP and 3-isobutyl-lmethylxanthine, 32P-labeling of the 26 kDa protein was observed.
  • 4.4. After treatment with snake venom phosphodiesterase, [32P]AMP was released from the 26kDa protein. Such release was not observed when cells were labeled with [γ-32P]ATP.
  • 5.5. The 32P-labeling pattern of proteins with [α-32P]ATP was clearly different from that with [adenylate-32P]NAD+.
  • 6.6. The results suggest that the 26 kDa protein is one of the adenylylation substrates in rat parotid acinar cells.
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14.
  • 1.1. Two proteinases have been identified in yolk granules of Nereis diversicolor mature oocytes, an aminopeptidase and an acid cysteine proteinase.
  • 2.2. The aminopeptidase was identified as a metallo-enzyme having a molecular weight of about 260 kDa.
  • 3.3. Except that the acid cysteine proteinase is a high molecular weight protein (200 kDa) and has a very low pH optimum (3.0), the enzyme possesses properties resembling those of mammalian cathepsin L.
  • 4.4. The cathepsin L-like proteinase was found to be liable to the in vitro proteolysis of the yolk granule proteins and is therefore suggested to be involved in yolk protein processing.
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15.
  • 1.1. Pseudomonas aeruginosa phospholipase C from culture supernatants of bacteria grown in high-Pi basal salt medium with choline, as the sole carbon and nitrogen source, was purified by precipitation with 70% saturation ammonium sulfate in the presence of celite.
  • 2.2. The PLC activity was eluted of this mixture by the use of a reverse gradient of 70-0% ammonium sulfate.
  • 3.3. The peak containing the PLC activity revealed a single protein after SDS-PAGE.
  • 4.4. The method could also be applied to purify PLC produced in a low-Pi complex medium. The resultant preparation was not homogeneous.
  • 5.5. The molecular weight for both PLC preparations was about 70 kDa.
  • 6.6. Both PLC used phosphatydilcholine and sphingomyelin as substrates, displayed hemolytic activity an exhibited an apparent KM of 25 mM for p-nitrophenylphosphorylcholine.
  • 7.7. They were not inhibited by 1% sodium deoxycholate but were 30% inhibited by 1% Triton X-100.
  • 8.8. 2% sodium dodecylsulfate and 1% tetradecyltrimethylammonium bromide inhibited the PLC from the HPl-BSM plus choline but not the enzyme from the LPl-CM.
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16.
  • 1.1. The native rat-kidney cortex Fructose-1,6-BPase is differentially regulated by Mg2+ and Mn2+.
  • 2.2. Mg2+ binding to the enzyme is hyperbolic and large concentrations of the cation are non-inhibitory.
  • 3.3. Mn2+ produces a 10-fold rise in Vmax higher than Mg2+. [Mn2+]0.5 is much larger than [Mg2+]0.5. At elevated [Mn2+] inhibition is observed.
  • 4.4. Mg2+ and Mn2+ produce antagonistic effects on the inhibition of the enzyme by high substrate.
  • 5.5. Fru-2,6-P2 inhibits the enzyme by rising the S0.5 and favouring a sigmoidal kinetics.
  • 6.6. The inhibition by Fru-2,6-P2 is released by Mg2+ and more powerfully by Mn2+ increasing the I0.5.
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17.
  • 1.1. Effect of controlled up- and down-shifts of growth temperature on the antioxidant enzymes activities and lipid peroxidation were investigated in intact cells of Cyanobacterium synechocystis PCC 6803 acclimated at different growth temperature.
  • 2.2. Algal cells grown at 36°C were treated at 20 and 43°C as down- and upward-shifts of growth temperature for 24 hr, respectively. At the down-shift of growth temperature the superoxide dismutase, catalase and glutathione peroxidase were significantly increased with concomitant decrease in protein content.
  • 3.3. These parameters showed similar temperature dependencies in the up-shift of growth temperature, they were decreased significantly.
  • 4.4. The increased hydroxyl (HO) radical and malonyldialdehyde (MDA) formation, when algal cells exposed to down-shift of growth temperature, supposedly due to stimulated production of superoxide radicals (O2) and hydrogen peroxide (H2O2) at lower temperature.
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18.
  • 1.1. Levels of progesterone, pregnenolone, testosterone, 5α-dihydrotestosterone, estrone and estradiol were measured by radioimmunoassay in purified gonadal extracts of larval and adult male and female Locusta migratoria.
  • 2.2. The average steroid contents varied between less than 1 ng to more than 160 ng/g tissue.
  • 3.3. Young adults were treated with precocene or ketoconazole in an attempt to influence the steroid contents in gonads.
  • 4.4. Ketoconazole treatment had no effect on the steroid contents in gonads whereas precocene treatment resulted in higher contents of androgens.
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19.
  • 1.1. A low molecular weight metal-binding protein was found in the snail Nassarius reticulatus cytosol, which was induced in heavy metal contaminated environments.
  • 2.2. In our sodium dodecyl sulfate-mercaptoethanol polyacrylamide gel systems it behaved as a protein of 19 kDa mol. wt.
  • 3.3. Amino acid composition studies definitely established this protein not to be metallothionein (Mt) like, because it had a much lower level of cysteine and substantial amounts of aromatic amino acids and histidine.
  • 4.4. The metal-binding strength of this protein was concluded to be much weaker than that of Mt.
  • 5.5. In the crustacean Pagurus bernhardus L. such a protein could not be demonstrated.
  • 6.6. In both the snail and the crustacean Zn may inhibit the accumulation of Hg. The premise for studying the induction of the metal-binding Nassarius protein as a supplement to environmental metal monitoring purposes is briefly discussed.
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20.
  • 1.1. Carbonyl reductase, which is distributed in both cytosolic and microsomal fractions in bovine liver, were purified to homogeneity on 12.5% sodium dodecylsulfate-polyacrylamide gel electrophoresis and shown to have molecular weights of 32 kDa and 68 kDa, respectively.
  • 2.2. Both carbonyl reductases can catalyze the reduction of many carbonyl compounds including ketone, quinones and aldehyde with relatively low Km values.
  • 3.3. From the absorption spectrum result, microsomal carbonyl reductase closely resembles cytochrome P-450 reductase.
  • 4.4. Cytosolic carbonyl reductase is a novel enzyme which can act on both testosterone and androsterone at low concentration.
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