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1.
《Comparative biochemistry and physiology. A, Comparative physiology》1986,83(3):503-505
- 1.1. The shell side of the mantle of Achatina fulica is several millivolts positive to the blood side in vitro.
- 2.2. The electrical potential does not depend on Na+, Ca2+, Mg2+, K+ or HCO3− but requires the presence of chloride on the shell side.
- 3.3. The potential difference and short-circuit current ranged from 3.0 to 30.0 mV and 15.0 to 75 μA/cm2 with averages at 10m V and 50 μA/cm2 respectively.
- 4.4. The electrical gradient is reduced by 2,4-dinitrophenol, thiocyanate and furosemide but not by ouabain, CO2 or acetozolamide.
- 5.5. It is suggested that the nature and mechanism of electrogenesis in Achatina parallels that of the Helix mantle.
2.
《The International journal of biochemistry》1994,26(8):1003-1008
- 1.1. The effects of prostaglandin (PG) E1, and I2 analogs (OP-41483 and OP-2507) on the Superoxide generation of human neutrophil NADPH oxidase (EC 1.6.99.6) in both whole-cell and cell-free systems were investigated.
- 2.2. In a whole-cell system, OP-2507 inhibited the Superoxide generation by neutrophils exposed to phorbol myristate acetate concentration-dependently through its superoxide-scavenging action.
- 3.3. The concentration of the drug required for 50% inhibition of the oxidase (IC50) was 21 μM.
- 4.4. In a cell-free system, however, the drug in concentrations of < 100 μM did not inhibit the activation of NADPH oxidase by sodium dodecyl sulfate because of its inactivation by the detergent.
- 5.5. Although PGE1 and OP-41483 did not inhibit the Superoxide production by stimulated neutrophils in a whole-cell system, they both inhibited the activation of NADPH oxidase in a cell-free system concentration-dependently, with IC50 values of 44 and 170 μM, respectively.
- 6.6. In addition, in the cell-free system, the Km value for NADPH of the oxidase was unchanged by PGE1.
- 7.7. The results suggest that the PGI2 analog, OP-2507, is a possible superoxide-scavenger and that PGE1 inhibits the NADPH oxidase activation by sodium dodecyl sulfate in a cell-free system concentration-dependently.
3.
《The International journal of biochemistry》1991,23(10):991-995
- 1.1. Purified ostrich (Struthio camelus) liver fructose-1,6-bisphosphatase exhibited an absolute requirement for Mg2+.
- 2.2. The enzyme catalyzed the hydrolysis of fructose-1,6-bisphosphate, sedoheptulose-l,7-bisphosphate and ribulose-l,5-bisphosphate.
- 3.3. S0.5 for substrate was 1.4 μM.
- 4.4. AMP was a potent non-competitive inhibitor with respect to substrate (Ki of 25 μM).
- 5.5. Fructose-2,6-bisphosphate was a potent competitive inhibitor of the enzyme (Ki of 4.8 μM).
4.
《Comparative biochemistry and physiology. A, Comparative physiology》1979,62(3):545-548
- 1.1. Adult male Atremia salina L. were acclimated to five different oxygen concentrations and their respiration in response to environmental oxygen concentrations was determined.
- 2.2. Anemia is a respiratory regulator over a wide range of partial O2 pressures. A critical oxygen tension exists and decreases with acclimation to lower pO2.
- 3.3. Hypoxic conditions induce the production of hemoglobin III.
- 4.4. Lactic acid is produced during anaerobiosis.
- 5.5. Production of Hb III and lactic acid, being inversely proportional to the acclimation level, has to be considered as a long term or short term adaptation to hypoxic conditions.
5.
《The International journal of biochemistry》1993,25(11):1561-1564
- 1.1. The effect of incorporating D2O into the incubation medium on glycolysis and gluconeogenesis by hepatocytes from fasted rats was examined.
- 2.2. The substitution by heavy water, D2O, at concentrations from 10 to 40%, stimulated glucose uptake, lactate production and CO2 yields from glucose. At 10 mM glucose, 40% D2O doubled glucose uptake, increased CO2 production by 40%, and increased lactate production by 350%.
- 3.3. The stimulation of lactate production decreased at higher glucose concentrations, but was still substantial even at 80 mM glucose.
- 4.4. There was no effect on CO2 production above glucose concentrations of 30 mM.
- 5.5. Ten percent D2O showed little inhibition of lactate uptake, its oxidation and gluconeogenesis. At 40% D2O the inhibition ranged from 10 to 20%.
- 6.6. No effect of D2O on the rate of glucokinase or glucose-6-phosphatase was observed.
- 7.7. The concentration of fructose, 2,6-P was not affected by D2O
6.
《The International journal of biochemistry》1984,16(8):875-881
- 1.1. Rat liver cytoplasmic acetyl-CoA synthetase was partially purified (purification factor = 23, yield = 30%).
- 2.2. The apparent Kms for acetate, coenzyme A, ATP and MgCl2 were determined and found to be 52.5 μM, 50.5 μM, 570 μM and 1.5 mM, respectively.
- 3.3. The partially-purified enzyme showed a low affinity for short-chain carbon substrates other than acetate.
- 4.4. The properties of the partially-purified enzyme were compared with those of enzymes from other sources.
7.
《Comparative biochemistry and physiology. B, Comparative biochemistry》1990,95(4):741-744
- 1.1. At 37 stations in the English Channel and the southern North Sea concentrations of four brominated phenols in Lanice conchilega were determined using ECD equipped capillary gas chromatography: 2,4-dibromophenol, 2,6-dibromo-4-methylphenol, 2,4,6-tribromophenol, 3,5-dibromo-4-hydroxybenzaldehyde.
- 2.2. Concentrations in worms of the southern North Sea were generally below 1 μg/g wet wt.
- 3.3. Levels were slightly raised in worms of sheltered shores, those of 3,5-dibromo-4-hydroxybenzaldehyde were increased in subtidal populations.
- 4.4. Concentrations in L. conchilega of Brittany were considerably higher than those in worms of the Frisian Islands, North Sea; they deviated from the latter by factors of 3, 16, 4, 4, respectively.
- 5.5. The reasons for the conspicuous differences are hitherto unknown; three explanations are suggested.
8.
《The International journal of biochemistry》1992,24(11):1691-1695
- 1.1. Regulatory properties of lipoxygenase activity in rat brain cytosol were studied using linoleic acid (LA) as a substrate.
- 2.2. A change in the absorbance at 234 nm was biphasic when a mixture of LA and pre-formed hydroperoxide (LA-OOH) was incubated with freshly isolated native brain cytosol. Initially, a rapid depletion of LA-OOH was observed with a concomitant formation of LA-oxo compounds. This phase was followed by LA dioxygenation.
- 3.3. Both hydroperoxidase and dioxygenase activities of lipoxygenase were inhibited by micromolar concentrations of classic lipoxygenase inhibitors (phenidone, 5,8,11-eicosatriynoic acid and nordihydroguaiaretic acid).
- 4.4. The dioxygenase activity in dialysed cytsool was stimulated by nanomolar concentrations of H2O2 and micromolar concentrations of LA-OOH and it was inhibited by serotonin, dopamine and norepinephrine (IC50 25–43 μM).
9.
《Comparative biochemistry and physiology. B, Comparative biochemistry》1987,86(4):1151-1155
- 1.1. Biliverdin reductase from the liver of eel, Anguilla japonica was characterized and purified with a novel enzymatic staining method on polyacrylamide electrophoretic gel.
- 2.2. This enzyme could use both NADPH and NADH as coenzyme. The Km of NADPH was 5.2 μM, while that of NADH was 5.50 μM.
- 3.3. The optimum reaction pH for using HADPH as coenzyme was 5.3. That for NADH was 6.1. The optimum reaction temperature is 37°C.
- 4.4. When NADPH was used as coenzyme, the Km of biliverdin was 0.6 μM. When NADH was used as coenzyme, the Km of biliverdin was 7.0 μM.
- 5.5. The activity of the enzyme was inhibited by the concentration of biliverdin. Also, the potency of the enzyme was much less than that of the analogous enzyme isolated from mammals.
- 6.6. This is a fairly stable enzyme with a mol. wt around 67,000. Its estimated pI was pH 3.5–4.0.
- 7.7. This is the first time biliverdin reductase has been isolated and characterized from a vertebrate other than mammals. The property of it is quite different from that of mammals.
10.
《The International journal of biochemistry》1983,15(5):651-656
- 1.1. A steady state kinetic investigation was performed on an improved preparation of rat-liver sorbitol dehydrogenase (l-iditol: NAD-oxidoreductase, EC 1.1.1.14).
- 2.2. Data analyses indicate the enzyme follows a rapid equilibrium random mechanism in the direction of sorbitol oxidation and a random mechanism in the direction of fructose reduction.
- 3.3. Kinetic constants were: KmNAD 0.082 mM; Kmsorbitol 0.38 mM; KmNADH 67 μm; Kmfructose 136 μM.
- 4.4. Evidence is adduced to indicate the more rapid reverse (fructose reduction) reaction is susceptible to metabolic control by formation of abortive enzyme-fructose-NAD and enzyme-NADH-sorbitol complexes.
11.
《Comparative biochemistry and physiology. A, Comparative physiology》1981,68(1):103-106
- 1.1. Healthy 6- to 12-day-old Heliothis zea (bollworm) larvae showed a mean oxygen uptake of 3.1 μl O2/mg body wt per hr.
- 2.2. Similar larvae infected with the fungus Nomuraea rileyi had a mean uptake of 4.01 μl O2/mg per hr.
- 3.3. The weights of the two groups of insects did not differ.
- 4.4. T-test showed a significant (P < 0.01) difference in oxygen uptake between healthy and infected larvae.
12.
《Comparative biochemistry and physiology. B, Comparative biochemistry》1986,83(3):569-573
- 1.1. A red-fluorescent blue protein (P600) was purified from the digestive juice of the silkworm (Bombyx mori L.) larvae raised on mulberry leaves.
- 2.2. The purified protein was electrophoretically homogeneous and showed the absorption maxima at 601.5 nm and 278 nm, and the fluorescence maximum at 621 nm.
- 3.3. The molecular weight was estimated to be 540,000 by gel filtration on Sepharose CL-6B. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate suggests that the protein consists of two heterogeneous polypeptide subunits with a mol. wt of 15,000 and 18,000.
- 4.4. The P600 contains excess acidic amino acid residues over basic groups. The polarity and pI were 45.5% and 4.6, respectively.
- 5.5. The production of H2O2 was observed in the presence of P600 upon illumination.
13.
《The International journal of biochemistry》1991,23(12):1445-1451
- 1.1. An alkaline p-nitrophenylphosphate phosphatase has been purified 440-fold from extracts of Hatobacterium halobium.
- 2.2. The enzyme has an apparent molecular weight of 24,000.
- 3.3. A Km value for p-nitrophenylphosphate of 1.12mM has been found under optimal conditions.
- 4.4. The enzyme is selectively activated and stabilized by Mn2+.
- 5.5. It requires high salt concentrations for stability and maximum activity.
- 6.6. It displays an unusual restricted substrate specificity of 25 phosphate esters tested, only phosphotyrosine and casein were hydrolysed besides p-nitrophenylphosphate.
14.
《The International journal of biochemistry》1992,24(10):1657-1660
- 1.1. A thermostable orthophosphoric monoester phosphohydrolase (EC 3.1.3.1) from Thermus sp strain Rt41A has been purified 400-fold to give a specific activity of 25 U/mg at 60°C in IM diethanolamine (pH 11.1).
- 2.2. The enzyme has a Mr of 160,000 and is trimeric.
- 3.3. The half-life of the enzyme is 5 min at 85°C.
- 4.4. The enzyme has a wide specificity for a number of phosphate monoesters.
- 5.5. The Hm of the enzyme is pH dependent, so the pH optimum of the enzyme is affected by the substrate concentration.
- 6.6. The enzyme is inhibited 50% by 20 mM Ca2+ or Mg2+.
- 7.7. The Ki for phosphate, EDTA-di sodium salt and arsenate (in 1 M diethanolamine, pH 11.1) is approx 1.2, 1.6 and 4mM respectively.
- 8.8. Urea (200 mM) is not inhibitory.
15.
《The International journal of biochemistry》1984,16(1):117-120
- 1.1. The specific activity of GMP synthetase was measured in several human tissues and found to be highest in cultured skin fibroblasts, followed by bone marrow, leukocytes, erythrocytes. placenta, and liver.
- 2.2. The enzyme from fibroblasts was purified approximately 50-fold by ammonium sulfate fractionation and gel filtration.
- 3.3. The Km values were determined to be 4.9μM for XMP, 270μM for ATP. and 340 μM for glutamine.
- 4.4. Ammonium sulfate could replace glutamine as the amino donor but was much less efficient.
- 5.5. The enzyme was specific for ATP as the energy source.
- 6.6. Unlike the calf thymus enzyme, the human enzyme has no requirement for a reduced sulfhydryl compound.
- 7.7. Human GMP synthetase is inhibited by ATP, dATP, azaserine, and hydroxylamine.
16.
《The International journal of biochemistry》1984,16(5):561-565
- 1.1. The decarboxylation of uroporphyrinogens I and III by porphyrinogen carboxy-lyase (EC 4.1.1.37) in mouse liver supernatant was compared in relation to substrate concentrations.
- 2.2. In this species uroporphyrinogen III was the best substrate judging by the criteria of Km/Vmax (estimated for total porphyrinogens) and was converted into coproporphyrinogen faster than its series I isomer.
- 3.3. The difference between the two isomers was mainly due to the first decarboxylation.
- 4.4. This difference was confirmed by calculation of the Hill coefficient and of Lineweaver-Burk plot which suggested that isomer I induced negative cooperativity in the active centre of the enzyme.
- 5.5. After treatment with a porphyrogenic dose of TCDD (25 μg/kg/week for 9 weeks) differences between uroporphyrinogen I and III as substrate were maintained.
- 6.6. In addition treatment reduced Vmax and Km (estimated for total porphyrinogens) of liver porphyrinogen carboxy-lyase to about half control values for both isomers.
- 7.7. Vmax was reduced mainly because of the formation of smaller amounts of all products of decarboxylation, and Km because more heptaporphyrinogen was formed than coproporphyrinogen.
- 8.8. Values of the Hill coefficient and Lineweaver-Burk plots suggested TCDD induced altered substrate affinity for isomer III too.
- 9.9. Treatment with TCDD did not affect the decarboxylation of uroporphyrinogen III by RBC porphyrinogen carboxy-lyase, estimated from Km and Vmax for total porphyrinogens formed.
17.
- 1.1. Water vapour conductance (GH2O) was determined for 25 grey heron Ardea cinerea eggs in the laboratory, and in nests during natural incubation at two Scottish colonies.
- 2.2. The mean GH2O of eggs measured in the nest which successfully hatched was 9.0 mgH;O/mmHg/day and the mean water vapour pressure gradient between egg and nest (ΔPH2O), measured using “calibrated” duck eggs, averaged at 31 mmHg (4.13 kPa).
- 3.3. Based on eggshell porosity results, from the eggs which hatched, such a gradient would result in a loss of water from the eggs during incubation equivalent to 11% of their fresh weight.
- 4.4. Shell thickness, the number of pores/cm2 of eggshell and DDE content were also determined for the 25 eggs measured in the laboratory.
- 5.5. Eggs containing high levels of DDE had thinner shells, more pores in the eggshell and a higher overall eggshell porosity.
- 6.6. The main problem posed by a high level of DDE would appear, however, not to be an excessive water loss from the egg during incubation, but rather eggshell thinning leading to a loss of the egg due to breakage in the nest.
18.
《Comparative biochemistry and physiology. B, Comparative biochemistry》1986,83(2):385-390
- 1.1. Cellular and intracellular localization of catalase and acid phosphomonoesterase in the midgut of Lumbricus terrestris was studied by use of tissue fractionation.
- 2.2. At least 60–70% of the catalase resides in the chloragocyte cytosol and the remaining 30–40% resides in gut epithelium peroxisomes.
- 3.3. One of the main functions of the chloragocyte catalase is probably scavenging for H2O2 arising from the interaction between blood heme-protein and oxygen.
- 4.4. A simple method for the histochemical detection of cytosol catalase is proposed.
- 5.5. About 10% of the gut acid phosphatase resides in chloragocyte lysosomes. The chloragosomes contain no acid phosphatase.
19.
《Comparative biochemistry and physiology. A, Comparative physiology》1984,77(1):155-159
- 1.1. The sea anemone, Bunodosoma cavernata, is a relatively eurybaline cnidarian tolerating salinities from 12 to 40%.
- 2.2. Taurine, glutamic acid and aspartic acid all showed some increases with increased salinity.
- 3.3. The amino acid showing the greatest accumulation under high salinity conditions was β-alanine which increased 28-fold from 1.5 to 41.9 μmol/g dry weight when salinity was raised from 26 to 40%.
- 4.4. When B. cavernata was subjected to increased salinity, β-alanine was rapidly accumulated and reached maximum levels within 4 days.
- 5.5. When salinity was dropped from 36 to 26%0, β-alanine concentrations dropped from 15 to 2 μmol/g dry weight in 2 days.
20.
《Comparative biochemistry and physiology. A, Comparative physiology》1984,77(4):691-693
- 1.1. The oxygen consumption rates for three sympatric species of marine gastrotrichs (anatomically similar, except that one contains hemoglobin) were measured with a Cartesian diver microrespirometer.
- 2.2. The rates for the two species without hemoglobin, Turbanella ocellata and Dolichodasys carolinensis, were 307.2 μl O2 g−1 hr−1 and 108.0 μl O2 g−1 hr−1, respectively, while the rate for the hemoglobin-containing species, Neodasys, was 208.9 μl O2 g−1 hr−1.
- 3.3. The possession of hemoglobin by Neodasys (14% by volume) cannot be explained by an unusually high demand for oxygen.
- 4.4. Instead, the hemoglobin may be useful as an oxygen store providing continued aerobic metabolism in anoxic conditions, thus allowing Neodasys to exploit a different niche.