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61.
A new type of two-dimensional electrophoresis for analysis of protein using cellulose acetate membrane has been developed. Prior to the separation, proteins in a sample are concentrated to a narrow zone on a strip of cellulose acetate according to “steady-state stacking” of isotachophoresis. Electroendosmotic counterflow on cellulose acetate membranes is advantageous for the isotachophoretic concentration of large sample volumes. The concentrated protein zone is then subjected to electrophoretic separation on the same strip. This first-dimensional separation including the concentrating process is named “concentrating electrophoresis.” Iso-electric focusing on several layers of cellulose acetate membrane is performed in the second-dimensional step. Many kinds of detection methods can be applied to the layers among which proteins are distributed. The novel two-dimensional electrophoresis takes only 5 h to perform. 相似文献
62.
In situ growth of Neomysis intermedia Czerniawsky at the post-embryonicstage was studied by the cohort analysis using the probabilitygraphic technique in a hypereutrophic temperate lake, Lake Kasumigaura.Two overwintering populations and 5 spring cohorts were recognizedover 2-yr field observations performed at 415 day intervals.There was no luck in order to follow possible cohorts in mid-summerand autumn. The specific growth rate of the post-embryonic stagedetermined varied between 0.001 and 0.16 (day 1) dependingupon the surrounding water temperature, and each individualgrowth showed an almost exponential pattern. Average size ofnew born individuals was {small tilde}2.1 mm in body lengthand was consistent regardless of the difference of seasons,but the average mature size was highly temperature dependent,ranging between 7.6 and 12.0 mm for males and 8.1 and 13.5 mmfor females. 相似文献
63.
Taka-amylase A (1,4-alpha-D-glucan glucanohydrolase, EC 3.2.1.1), which contains a single asparagine-linked oligosaccharide unit, was digested with almond glycopeptidase immobilized on Sepharose 6B at 20 degrees C for 4 h. A maximum of 10% of the parent protein was isolated as apoprotein by column chromatography on Con-A Sepharose. The characteristics of the apoprotein were compared to those of the native Taka-amylase A. The removal of the sugar chain from Taka-amylase. A caused no change in the pH-activity profile or in kinetic parameters of the hydrolysis of soluble starch. The stability of the apoprotein toward changing pH and digestion by proteases did not show any appreciable difference from that of the native Taka-amylase. These results suggest that the carbohydrate moiety of Taka-amylase A is not an essential participant in the catalysis. 相似文献
64.
Antibacterial and bactericidal activities of tea extracts and catechins against methicillin resistant Staphylococcus aureus] 总被引:2,自引:0,他引:2
M Toda S Okubo Y Hara T Shimamura 《Nihon saikingaku zasshi. Japanese journal of bacteriology》1991,46(5):839-845
We examined tea extract, (-) epigallocatechin gallate (EGCg) and theaflavin digallate (TF3) for their antibacterial and bactericidal activities against methicillin resistant Staphylococcus aureus (MRSA) and food poisoning strains of S. aureus. Twenty percent tea extract (50 microliters), EGCg (63 micrograms) and TF3 (125 micrograms) added to one ml of culture medium each inhibited the growth of all strains of MRSA and food poisoning S. aureus tested. Tea extract showed also a bactericidal activity against MRSA even at the same concentration of as in ordinarily brewed tea. EGCg at a concentration of 250 micrograms/ml showed a bactericidal activity against MRSA but not against food poisoning S. aureus, but at 500 micrograms/ml reduced markedly the viable number within 48h. These results suggest that tea and catechin can be used as prophylactic agents against MRSA infection. 相似文献
65.
A new type of bubble aeration column called a hollow fiber membrane (HFM) aeration column was proposed, which was featured in the use of hollow fiber membranes and gave a high bubble density in the column. The value of k(L)a was increased by modifying the membrane surface for making the pore size smaller. The Sauter mean diameter of bubbles (D(vs)) was 2.0 +/- 0.1 mm in the range of the superficial gas velocity from 0.02 m s(-1) to 0.065 m s(-1), while that obtained for the bubbles near the membrane was 811 mum at the superficial gas velocity of 4.0 x 10(-4) m s(-1). The difference was ascribed to the effect of coalescence of bubbles. The value of K(L)a increased in proportion to the superficial gas velocity up to 0.02 m s(-1), and was almost constant above 0.03 m s(-1). The maximum value of k(L)a, 2.5 s(-1), was higher than those of the other aeration columns reported previously. The pneumatic power consumption per unit liquid volume (P(v)) for obtaining the same k(L)a was the smallest in the HFM aeration columns. P(v), for obtaining the same interfacial area of bubbles per liquid volume, was also lower than those for other types of aeration columns. It was suggested from the measurement of bubble diameter that the larger interfacial area generated in the HFM aeration column ascribes to the larger gas holdup than the smaller D(vs). (c) 1992 John Wiley & Sons, Inc. 相似文献
66.
The complete amino acid sequence of calmodulin from Euglena gracilis was determined by isolation and sequence analyses of peptides derived from calmodulin by digestion with trypsin and Staphylococcus aureus V8 protease. Euglena calmodulin consists of 148 amino acid residues; it lacks tryptophan and cysteine and contains one tyrosine, three histidine and two NE-trimethyllysine residues/molecule of the protein. Its N-terminus was blocked with an acetyl group and C-terminal lysine was trimethylated. Euglena calmodulin is the first calmodulin so far examined in which the C-terminal lysine is trimethylated. The comparison of amino acid sequences between Euglena and human brain calmodulins indicated 17 amino acid substitutions in Euglena calmodulin. 相似文献
67.
Isolation of a full-length cDNA encoding mouse aromatase P450 总被引:1,自引:0,他引:1
M Terashima K Toda T Kawamoto I Kuribayashi Y Ogawa T Maeda Y Shizuta 《Archives of biochemistry and biophysics》1991,285(2):231-237
A full-length cDNA clone for aromatase P450 has been isolated from a pregnant mouse ovarian cDNA library. The insert of this clone (2394 bp) contains a 1509-bp open reading frame encoding 503 amino acid residues together with a 46-bp 5'-untranslated stretch and an 839-bp 3'-untranslated region to which a poly(A) tract is attached. Northern blot analysis of ovarian RNA from pregnant mice reveals a major mRNA band of 2.5 kb with a minor band of 2.1 kb. Comparison of mouse aromatase P450 with that of rat, human, and chicken shows 91, 81, and 69% identity in the nucleotide sequence and 92, 79, and 69% identity in the deduced amino acid sequence, respectively. The membrane-spanning domain of mouse aromatase P450 is estimated to be an extremely hydrophobic segment located within the N-terminal region of the molecule. Furthermore, a highly conserved heme-binding domain is noticed. 相似文献
68.
The B subunit of cholera toxin enhances DNA synthesis in rat hepatocytes induced by insulin and epidermal growth factor. 总被引:2,自引:0,他引:2
H Mitsui M Iwamori N Hashimoto H Yamada Y Ikeda G Toda K Kurokawa Y Nagai 《Biochemical and biophysical research communications》1991,174(1):372-378
The B subunit of cholera toxin, which binds to ganglioside GM1, enhanced DNA synthesis in rat hepatocytes in primary culture induced by insulin and/or epidermal growth factor. The effect was dose-dependent, and whole cholera toxin, activating adenylate cyclase, showed a higher effect than the B subunit alone. The B subunit acted additively with other agents that also increase cyclic AMP levels. A competitive antagonist of cyclic AMP could not suppress the effect of the B subunit completely. These data suggest that the effect is independent of the cyclic AMP signal pathway, and that GM1 plays a role in hepatocyte proliferation. 相似文献
69.
Down-regulation of prostaglandin E2 receptors in regenerating rat liver and its physiological significance. 总被引:2,自引:0,他引:2
N Hashimoto T Watanabe Y Ikeda G Toda H Yamada Y Yoshikawa H Mitsui K Kurokawa 《Biochemical and biophysical research communications》1991,176(1):226-232
The properties of prostaglandin (PG) E2 receptors in regenerating liver were studied using rat hepatocytes in primary culture. The control cells possessed stereo-specific PGE2 receptors with Bmax and Kd values, at 4 degrees C, of 526 fmol/mg protein and 6.5 nM respectively. In cells from regenerating liver after 70% hepatectomy, Bmax was reduced to 42-43% that of the controls; Kd did not change. Administration of indomethacin before surgery prevented Bmax reduction. These results indicate that PGE2, produced during the regeneration process, evoked cellular events and regulated the density of its receptors. 相似文献
70.
Measurement of voltage dependence of capacitance of planar bilayer lipid membrane with a patch clamp amplifier. 总被引:1,自引:1,他引:0 下载免费PDF全文
The voltage dependence of capacitance was measured by using the setup which was almost the same as that for the study of ion channels. The coefficient which represents the voltage dependence of capacitance itself also changes as a function of the duration of voltage application if hexadecane is contained in bilayer lipid membrane (BLM). The method of Alvarez, O., and R. Latorre (1978. Biophys. J. 21:1-17) was extended to treat BLM with hexadecane. 相似文献