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131.
132.
Protein synthesis during germination at 24?C and vernalizationat 4?C in winter wheat embryos were investigated with a cell-freesystem. During germination, the capacity for protein synthesisincreased in the early stage between 12 and 36 hr of imbibitionthen declined to a final low level between 48 and 72 hr. Thistransition was due to quantitative changes of the activitiesof ribosomal and supernatant fractions in the early stage andmainly to those of the supernatant fraction in the later stage.During vernalization, the capacity for protein synthesis continuedto decline over 15 to 60 days at 4?C. This transition was dueto the change in activity of the supernatant fraction; the activityof the ribosomal fraction was nearly constant. Electrophoretic analysis of in vitro products indicated thatthe high molecular weight proteins present in 12-hr embryoshad disappeared in 48-hr germinated wheat embryos and that theproducts in 24- and 36-hr embryos were types intermediate betweenthose of 12- and 48-hr embryos. The products in each vernalizedembryo resembled those in 24- and 36-hr germinated embryos.Therefore, it was concluded that the mRNA species for translationchanged during germination and vernalization in winter wheatembryos. (Received January 20, 1977; ) 相似文献
133.
Sexual cell division and activation of gametangial cells forconjugation in Closterium acerosum were induced by light. L200cells conjugated at maximum level under the following conditions;(i) a light intensity higher than 1,000 lux in a 16-hr lightand 8-hr dark regime and (ii) an illumination time longer than12 hr at 3,000 lux. L200 cells also conjugated under continuousillumination at 3,000 lux. The action spectrum for the activation of gametangial cellshad peaks around 450, 611 and 665 nm. 3-(4'-Chlorophenyl)-l,l-dimethylurea (CMU) inhibited the accumulationof carbohydrates and sexual cell division at 105 M andthe activation of gametangial cells for conjugation at 104M. (Received August 15, 1977; ) 相似文献
134.
135.
Fine structure of the recB and recC gene region of Escherichia coli 总被引:14,自引:0,他引:14
M Sasaki T Fujiyoshi K Shimada Y Takagi 《Biochemical and biophysical research communications》1982,109(2):414-422
136.
Oligomycin reduced the fluorescence intensity of an N-(p-(2-benzimidazoly)phenyl) maleimide (BIPM) probe at Cys-964 of the alpha-chain of pig kidney Na+,K(+)-ATPase with increase in the concentration of Na+ with a Hill coefficient of nh = 0.77 with Kh = 231 mM. The maximum fluorescence decrease was around 80% of the value observed after accumulation of ADP-sensitive phosphoenzyme (E1P) in the presence of 2 M Na+. The addition of Mg2+ and ATP with Na+ or choline chloride to give the same final ligand concentration to the Na(+)-enzyme-oligomycin complex formed with 16 mM Na+ + 1,984 mM choline chloride or 2 M Na+ induced rapid phosphorylation (20 or 21/s) and slower fluorescence decrease (12.1 +/- 1.2 or 10.1 +/- 3.2/s). These additions to the Na(+)-enzyme complex formed under the former or the latter conditions induced slow phosphorylation (13/s) prior to a much slower fluorescence decrease (3.4 +/- 0.3 or 8.6 +/- 0.7/s). The addition of Ca2+ and ATP to these enzyme complexes induced rapid fluorescence changes (21-11/s) followed by one order of magnitude slower rates of phosphorylation (1.5-1.3 s). These data suggest that the decrease in BIPM fluorescence induced by ATP with Ca2+ or with Mg2+, reflects the change of the Na+ binding state before or after the formation of E1P, respectively. 相似文献
137.
K Kitamura Y Mizuno A Sasaki A Yasui S Tsuiki K Kikuchi 《Journal of biochemistry》1991,109(2):307-310
A cDNA clone containing the full coding sequence of a type 1 protein phosphatase catalytic subunit 1 alpha has been isolated from a rat kidney lambda gt 10 library. The protein sequence deduced from the cDNA contains 330 amino acid residues with a molecular mass of 38 kDa. The cDNA clone from rat kidney was 89% identical at the nucleotide level in the coding region to type 1 protein phosphatase 1 alpha from rabbit skeletal muscle. However, the two protein sequences were completely identical. The type 1 alpha protein phosphatase from rat kidney shows 49% homology of amino acid sequence to the rat type 2A alpha protein phosphatase. Thus, the protein sequence of type 1 alpha protein phosphatase was completely conserved between rat and rabbit. The mRNA levels of type 1 protein phosphatase were determined in rat liver, AH13, a strain of rat hepatoma, and regenerating rat liver by Northern blot analysis using the cDNA fragment as a probe, under which conditions a single mRNA of 1.5 kb was detected. The mRNA levels of AH13 were remarkably increased when compared to those of normal ivers, whereas the mRNA levels of regenerating livers were slightly but significantly increased. These results demonstrate a marked increase in gene expression of type 1 protein phosphatase in hepatoma cells, suggesting an important role of the type 1 protein phosphatase in hepatocarcinogenesis. 相似文献
138.
S Bohnet L Rogers G Sasaki P E Kolattukudy 《The Journal of biological chemistry》1991,266(15):9795-9804
During the mating season the female mallards produce sex pheromones, diesters of 3-hydroxy fatty acids, in their uropygial glands. Subcellular fractionation by sucrose and Nycodenz density gradient centrifugations and electron microscopic examination of the fractions showed that diesters of 3-hydroxy acids and the enzymes that catalyze the formation and esterification of the 3-hydroxy fatty acids are located in the catalase-containing fractions, probably peroxisomes, whereas monoester synthesizing activities are located in the endoplasmic reticulum. Fatty acyl-CoA reductase that would provide fatty alcohol needed for the synthesis of monoester and diester waxes was found both in the peroxisomal and endoplasmic reticulum fraction. Upon daily intramuscular injection of estradiol into the females in the nonmating season, the short chain monoester waxes of the uropygial glands were replaced by long chain monoester waxes, and subsequently the monoester waxes were replaced by diester waxes. Injection of thyroxine with estradiol hastened the induction of the compositional changes including diester synthesis. Similar changes, including the synthesis of the female pheromones, were induced in the uropygial glands by the hormone treatment of males that do not normally produce diesters at any time during their life cycle. The structure and composition of the diesters induced by hormone treatment of both males and females were identical to those of the female pheromones produced during their mating season. Electron microscopic examination of diaminobenzidine-treated glands showed that peroxisomes proliferated in the gland of the females in the mating season and in the estradiol-treated males that produce the diesters. 相似文献
139.
Orientation of mineral in bovine bone and the anisotropic mechanical properties of plexiform bone. 总被引:3,自引:0,他引:3
Angular dependent Young's modulus E phi presented by Bonfield and Grynpas [Nature 270, 453-454 (1977)] was simulated by using the distribution function of the orientation of mineral in plexiform bone introduced on the basis of an X-ray pole figure analysis (XPFA) and a small angle X-ray scattering (SAXS) results. Calculations were performed with the aid of a simple model which expresses well the geometrical characteristic of plexiform bone. Estimated angular dependent Young's modulus in terms of the distribution of mineral orientation reproduced the experimental results. The suitable aspect ratio of bone mineral for the reproduction of the empirical data was a reasonable value compared with the morphological study of bone mineral. It is concluded that the angular dependence of mechanical properties of plexiform bone is explained by the distribution of bone mineral orientation and its morphology. 相似文献
140.
S Takahashi M Nose J Sasaki T Yamamoto M Kyogoku 《Journal of immunology (Baltimore, Md. : 1950)》1991,147(2):515-519
MRL/Mp-lpr/lpr (MRL/lpr) mice spontaneously develop lethal glomerulonephritis (GN) similar to human lupus nephritis, associated with the expression of lymphoproliferation gene lpr. To examine whether a particular IgG subclass is responsible for development of GN in these mice, first quantitative analysis of IgG subclasses in serum and in kidney eluates was performed. Although IgG2a was the dominant subclass in serum throughout the lifespan of mice, the IgG3 level in kidney eluates was three times higher than that of IgG2a at the 16 wk of age, which is the time of onset of development of severe GN. In sera of the 12-wk-old mice, half of the IgG3 was in immune complex form, whereas IgG2a in this form was only 17% of the total amount. Second, cyclosporin A, which ameliorates GN in MRL/lpr mice despite autoantibody production, was found to reduce serum IgG3 and mRNA levels, associated with the revision of cationic shift of the serum IgG3 spectrotype seen in isoelectric focusing. Third, among the hybrid mice with non-autoimmune-prone C3H/HeJ-lpr/lpr (C3H/lpr) mice, MRL/lpr x (MRL/lpr x C3H/lpr) F1, in which the genetic background for GN is likely segregated, the mRNA level for IgG3 correlated well with the degree of glomerular lesion. These findings indicate that production of IgG3 in MRL/lpr mice is one of the major factors responsible for development of GN in these mice, and that this is due to the genetic background of the MRL strain. 相似文献