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51.
Binding of a fluorescent allosteric effector, beta-naphthyl triphosphate (beta-NapP3), to human adult hemoglobin (HbA) at various levels of oxygen saturation were investigated by simultaneous measurements of fluorescence, absorbance and oxygen partial pressure. Amounts of beta-NapP3 bound to HbA were easily estimated from the fluorescence intensities of HbA solutions, because it was previously proved that the fluorescence of beta-NapP3 bound to HbA is completely quenched. Exchange reactions of the above fluorescent allosteric effector with 2,3-bisphosphoglycerate (DPG) were also examined at various levels of oxygen saturation. It was found that beta-NapP3 binds to deoxyHbA tetramer in the molar ratio of 2:1, and that one of the two beta-NapP3 competes with DPG. It was also found that beta-NapP3 binds to completely oxygenated HbA tetramer in the molar ratio of 1:1, and that the bound beta-NapP3 was not released by adding DPG. The binding affinity of beta-NapP3 for the noncompetitive site of completely oxygenated HbA, to which DPG does not bind, was smaller than that for the noncompetitive site of deoxyHbA, to which DPG also does not bind. Furthermore, the correlations between oxygen bindings by HbA and the bindings of beta-NapP3 to HbA in the intermediate stages of deoxygenation were investigated. It was revealed that HbA as a tetramer exists in three conformational states rather than simple two states as Monod, Wyman, and Changeux had proposed. 相似文献
52.
Phenotypic and chemotaxonomic characteristics of five isolates of acetylenereducing (nitrogen-fixing) oligotrophic bacteria from a paddy soil were investigated. They showed similar phenotypic characteristics: they were aerobic, asporogenous, gram-negative, motile by a polar flagellum, and irregular rods. On full strength nutrient broth (NB) growth was severely suppressed, but well supported on 10-to 10000-fold diluted NB. They consumed glucose but produced no acid, and also utilized phenolic acids such as ferulic acid or p-coumaric acid. The cellular fatty acid composition, quinone system and DNA base composition of the isolates were investigated. Cellular fatty acids mainly consisted of straightchain unsaturated C18 : 1 (62–81% of total fatty acids). Ubiquinone Q-10 and a high guanine-plus-cytosine content (65.1–66.0 mol%) were found. The taxonomic status of the isolates is discussed and a new genus, Agromonas, with a single species Agromonas oligotrophica sp. nov., is proposed for these isolates. The type strain of A. oligotrophica is JCM 1494. 相似文献
53.
Hiroyuki Masatomi 《Journal of Ethology》1983,1(1-2):62-69
Responding to the actions of the mate and taking somewhat fixed patterns,Grus japonensis, G. vipio, G. antigone, Anthropoides paradisea andBalearica regulorum pairs are finally led to copulation by a sequence of mating behaviours. There are slight differences in pre-copulatory behaviour patterns between the species and the female's ‘wing-spreading’, being the soliciting and key posture for copulation, differs between the genera; The female's wings are spread wide inGrus, fairly wide inAnthropoides, and are almost folded inBalearica. Post-copulatory behaviours, however, have definite species-specific characters. They usually consist of ‘head-down’ (bowing) or ‘warping’, ‘arching’, etc. immediately following the dismounting of the male inGrus. But a pair ofBalearica first keep their heads high, or gaze at each other for a while, and then show remarkable ‘ruffle-bowing’. These characteristic post-copulatory behaviours are obviously correlated with the threat displays, evolved under agonistic situations, typical to each species. 相似文献
54.
55.
T Suda N Horiuchi S Sasaki E Ogata I Ezawa 《Biochemical and biophysical research communications》1973,54(2):512-518
Kidney mitochondria were isolated from rachitic chicks and their activity in the metabolism of 25-OH-D3 was studied in relation to the amount of calcium added . The addition of 0.050.2 mM calcium to a mitochondrial suspension caused a marked and dose-related stimulation of 1-hydroxylation. A sharp decline in the activity was induced by higher concentrations (0.3-0.5 mM) of calcium. The rate of 24-hydroxylation was not influenced by calcium. In these effects, calcium was relatively specific among various divalent cations. These data strongly suggest that calcium is directly involved in the regulation of the vitamin D activation in kidney mitochondria. 相似文献
56.
57.
Tadao Niijima Takashi Umeda Manabu Kuriyama Hiroyuki Ohmori Yohsuke Matsumura Tomoyasu Tsushima Toyoko Tanahashi Jun Yoshimoto Toshihiko Asahi Norimasa Ike Taiichiro Johsen Noritaka Ishido Naoki Mitsuhata Takeshi Uyama Hiroyoshi Tanaka Hideo Ueda Jisaburo Sakatoku Norio Yamamoto Kazuo Nagata Yukitoshi Fujita Masaaki Morioka Kazuo Kurokawa Susumu Kagawa Tomoyuki Ishibe Yasutoshi Himeno Toyofumi Ueda 《Cancer immunology, immunotherapy : CII》1989,30(2):81-85
Summary In order to examine its clinical efficacy, recombinant human interferon- (rIFN-) was instilled intravesically into 51 patients with superficial bladder cancer. Ten patients, who received intermittent intravesical instillation at a dose of (3–36) × 106 U rIFN- on days 1–3 every week, showed no response. Thirty-two patients received intravesical instillation at a dose of (3–36) × 106 U every day for 10–20 days. Eight patients showed partial response, indicating an efficacy rate of 25%. Nine patients received divided doses of 18 × 106 U twice a day every day for 10–20 days. Six patients showed partial response, indicating an efficacy rate of 67%. This value was significantly higher than that obtained by administering divided doses. The response to intravesical instillation therapy with rIFN- varies with treatment protocol. Frequent and longer exposure to rIFN- may induce better regression of superficial bladder cancer. Six incidences of side-effects were found in five cases (9.8%): pollakiuria in one, pain on micturition in two, fever in two, and eruption in one case. All of these side-effects were slight and reversible after drug withdrawal. Laboratory tests showed only a few changes with low severity. Thus, rIFN- is potentially a new drug for instillation therapy of superficial bladder cancer, in view of the absence of adverse effects. 相似文献
58.
Double-strand cleavage and strand joining by the replication initiator protein of filamentous phage f1 总被引:4,自引:0,他引:4
The replication initiator protein (gene II protein (gpII] of bacteriophage f1 is a multifunctional protein that plays central roles in initiation and termination of phage DNA replication. It introduces a nick at a specific site on the (+)-strand of supercoiled replicative form DNA. The 3'-hydroxyl end of the nick serves as the primer for (+)-strand rolling-circle replication. Upon completion of a round of synthesis, gpII cleaves and circulaizes the displaced single strand. When Mn2+ is included in the buffer instead of Mg2+, gpII cleaves both strands. In this paper, we investigate the mechanism of the Mn2+-dependent double-strand cleavage activity of gpII. This reaction, unlike nicking in the presence of Mg2+, does not require superhelicity. The reaction proceeds in two kinetic steps: first nicking of the (+)-strand, and then cleavage of the (-)-strand. The nucleotide sequence requirement for nicking is reduced compared to that in the presence of Mg2+. The product of the double-strand cleavage has an unusual structure. The left end is a telomere-like hairpin since the (+)- and (-)-strands are joined, as demonstrated by base sequencing. The right end has a onebase 3'-overhang. This reaction probably reflects the cleavage-joining activity of gpII in the termination event. 相似文献
59.
Two variants of carrot (Daucus carota L. cv. MS Yonsun) celllines, which had been selected with Al-phosphate as a sole sourceof phosphorous, were characterized on their mechanisms of phosphate-utilizationfrom Al-phosphate. Both cell lines excreted citrate into themedium. The amount of citrate excretion was highly correlatedwith cell growth in the presence of Al-phosphate. There wasabout a 1 to 1 correlation between solublized-Al and excreted-citratein the medium during cell growth. These results suggest that1) the citrate could chelate with Al, at a 1 to 1 ratio, inAl-phosphate, 2) the citrate-chelated Al remains outside thecells, and 3) solublized phosphate from Al-phosphate is utilizedfor the growth of carrot cells. The characteristics of the selectedcells were very stable, since the rate of citrate-excretionshowed no change after subculturing 25 passages without Al-phosphate. (Received August 7, 1989; Accepted October 19, 1989) 相似文献
60.
Hiroyuki Tsunoda Toshio Ohshima Jun Tohyama Masayuki Sasaki Norio Sakuragawa Frank Martiniuk 《Human genetics》1996,97(4):496-499
We report a missense mutation in an adult Japanese patient with acid alpha-glucosidase (GAA) deficiency. A TC to GT transition
at nucleotides 1585–1586, was identified. This transition resulted in an amino acid substitution of Ser-529 to Val (S529V)
in exon 11. We also have demonstrated that the S529V mutation abolishes the catalytic activity of the enzyme. Our data suggest
that this mutation is the cause of the clinical manifestation known as adult-onset GAA deficiency. The missense mutation described
here is a new mutation, and the first identified in Japanese patients with GAA deficiency.
Received: 23 May 1995 相似文献