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31.
Hideya Hayashi Seiji Ito Teruo Tanaka Manabu Negishi Hideo Kawabe Yokohama Hiromitsu Kikuko Watanabe Osamu Hayaishi 《Prostaglandins & other lipid mediators》1987,33(4)
In view of the recent finding that prostaglandin D2 is stereospecifically converted to 9α,11β-prostaglandin F2, an isomer of prostaglandin F2α, a highly specific and sensitive radioimmunoassay for 9α,11β-prostaglandin F2 was developed and applied to determine the content of this prostaglandin in various rat tissues. Antisera against 9α-11β-prostaglandin F2 were raised in rabbits immunized with the bovine serum albumin conjugate, and [3H]9α,11β-prostaglandin F2 was enzymatically prepared from [3H]prostaglandin D2. The assay detected 9α,11β-prostaglandin F2 over the range of 20 pg to 1 ng, and the antiserum showed less than 0.04% cross-section with prostaglandin F2α, prostaglandin F2β and 9β,11β-prostaglandin F2. To avoid postmortem changes, tissues were frozen in liquid nitrogen immediately after removal. The basal level of 9α,11β-prostaglandin F2 was hardly detectable in various tissues of the rat examined, including spleen, lung, liver and brain; although it was found to be 0.31 ± 0.06 ng/g wet weight in the small intestine. During convulsion induced by pentylenetetrazole, enormous amounts of prostaglandin D2 (ca. 180 ng/g wet weight) and prostaglandin F2α (ca. 70 ng/g) were produced in the brain; however, 9α,11β-prostaglandin F2 was detected neither there nor in the blood. This result demonstrates that the conversion to 9α,11β-prostaglandin F2 is a minor pathway, if one at all, of prostaglandin D2 metabolism in the rat brain. 相似文献
32.
Atsushi Ikai Masaaki Nishigai Toshiya Osada Hideo Arakawa Masako Kikuchi 《The protein journal》1987,6(1):81-93
The plasma α2-macroglobulin and its egg white homologue ovomacroglobulin were purified from several different species and their structure before and after the reaction with proteinases studied by electron microscopy. The negatively stained specimens showed either a ringlike structure or a flowerlike one before the reaction with proteinses, but their structures changed into open rectangular ones after the reaction. The translational frictional ratio f/f 0 of human α2-macroglobulin and crocodilian ovomacroglobulin given in the literature is between 1.5 and 1.6 before and after the reaction with proteinases. The value reflects asymmetry due not to a high axial ratio, but rather to an openness of the structure resulting in a partially free draining character of the molecules. The computational method developed by Bloomfield and his co-workers based on the formalism of Kirkwood is used to calculate the frictional ratio of several models constructed from small spheres. The overall shape of the models is derived from electron micrographs. Although the degree of hydration is an unknown parameter in the calculation, reasonable agreement is obtained between the experimental values of f/f 0 and the calculated ones. Combination of electron microscopic and hydrodynamic methods would be fruitful in the structural study of giant proteins such as α2-macroglobulin. 相似文献
33.
Charles Romeo Naoko Moriwaki Kerry T. Yasunobu Irwin C. Gunsalus Hideo Koga 《The protein journal》1987,6(3):253-261
The first 12 NH2-terminal amino acids of the Pseudomonas putida putidaredoxin reductase were shown to be Met-Asn-Ala-Asn-Asp-Asn-Val-Val-Ile-Val-Gly-Thr. Comparison of these data with the DNA sequence of the BamHI-HindIII 197-base fragment derived from the PstI 2.2-kb fragment obtained from the P. putida plasmid showed that the putidaredoxin reductase gene was downstream from the cytochrome P-450 gene and the intergenic region had the 24-nucleotide sequence TAAACACATGGGAGTGCGTGCTAA. The Shine-Dalgarno sequence GGAG was detected in this region. The initiating triplet for the reductase gene was GTG, which normally codes for valine, but in the initiating codon position codes for methionine. From the amino acid sequence and X-ray data comparisons with other flavoproteins, what appears to be the AMP binding region of the FAD can be recognized in the NH2-terminal portion of the reductase involving residues 5–35. 相似文献
34.
35.
The changes in chlorophyll-protein complexes (CPs) in cucumbercotyledons during illumination and subsequent dark incubationwere studied by SDS-polyacrylamide gel electrophoresis. Whenetiolated cucumber seedlings were illuminated, chlorophyll wassynthesized and CPs were formed. In the early phase of greening(6 h of illumination), light-harvesting chlorophyll a/b-proteincomplex (LHCP) was the main GP. As the greening proceeded, P700chlorophyll a-protein complex (CP1) accumulated. When 6-h illuminatedseedlings were transferred to darkness, CP1 accumulated concomitantlywith a decrease in LHCP without new chlorophyll synthesis. Thechanges in the amounts of CPs in the dark became smaller withthe progress of greening and were not observed after 72 h ofillumination. These changes were confirmed by examining thechlorophyll/P700 ratio and the low temperature absorption spectrumof cotyledons. These results suggest that in the early phaseof greening, CPs were unstable and their chlorophyll moleculeseasily exchanged with those of other kinds of CPs. (Received October 14, 1982; Accepted December 1, 1982) 相似文献
36.
Cytochrome b561 was removed from chromatophores of a photoanaerobicallygrown Rhodopseudomonas sphaeroides by deoxycholate-cholate andTriton X-100 treatments of the chromatophores. The cytochromewas purified by ammonium sulfate fractionation and gel filtration.Its molecular weight was 45,000 (45 kD) and it was composedof three subunits with molecular weights of 23 kD, 19 kD andless than 6 kD. The cytochrome preparation had absorption maximaat 414 nm in the oxidized form, and at 428, 530 and 561 nm inthe reduced form. Its pi was 4.8. The midpoint potential ofthis cytochrome was 153 mV at pH 7.0. The compound was autooxidizable,and it had cytochrome c oxidase activity. (Received May 16, 1983; Accepted September 8, 1983) 相似文献
37.
Investigations of rhubarb and the bark of Rhaphiolepis umbellata led to the isolation of new flavan-3-ol glucosides. Their structures were elucidated on the basis of 1H and 13C NMR analysis hydrolytic studies as (+)-catechin 5-O-β-d-glucopyranoside and (?)-catechin 7-O-β-d-glucopyranoside. 相似文献
38.
Molecular and Cellular Biochemistry - 2,3-Bisphosphoglycerate accumulates in mammalian erythrocytes, where it facilitates the supply of oxygen to the tissues by binding to hemoglobin. Regulatory... 相似文献
39.
Inhibition of Thiamine Pyrophosphate Utilization by Thiamine or Its Monophosphate in Escherichia coli 下载免费PDF全文
The growth of a thiamine pyrophosphate auxotroph of Escherichi coli was inhibited by either thiamine or thiamine monophosphate, and the growth of a thiamine monophosphate auxotroph was inhibited by thiamine. The thiamine pyrophosphate-dependent oxidation of pyruvate was inhibited by thiamine with whole cells of the thiamine pyrophosphate auxotroph but not with cell extracts prepared from the same organism. In addition, the thiamine pyrophosphate uptake of the thiamine pyrophosphate auxotroph was inhibited by either thiamine or thiamine monophosphate. Although the thiamine pyrophosphate uptake of a revertant, selected for prototrophy from the thiamine monophosphate auxotroph, was inhibited by thiamine to an extent comparable to that observed with the thiamine monophosphate auxotroph, its growth was no longer inhibited by thiamine. A possible mechanism for the inhibition by thiamine and thiamine monophosphate in the utilization of thiamine pyrophosphate is discussed. 相似文献
40.
Nitrate and ammonium were shown to alter the growth ofRhodotorula glutinis var.salinaria in saline and non-saline media. In saline medium in which ammonium was the sole nitrogen source, ammonium inhibited growth
in the presence of molybdate ions. Detailed comparisons of the growth in saline and non-saline media when nitrate was supplemented
in the presence of molybdate ions showed that differences in utilizability of purine bases of nucleic acid were responsible
for the differences in growth,i.e. adenine increased the growth in such saline medium, but decreased it in non-saline medium. There was not such a specific
requirement for adenine in saline medium in the presence of molybdate ions when nitrate was substituted for ammonium as the
sole nitrogen source. It was suggested that adenine might provide the necessary skeleton of nucleic acid for serving nitrate
reduction in saline medium. 相似文献