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41.
A Kaidow T Kataoka M Wachi A Takada M Yamasaki K Nagai 《Journal of bacteriology》1992,174(16):5454-5456
Three proteins with molecular masses of 35, 55, and 75 kDa were found in an oriC complex fraction after purification through CsCl density gradient centrifugation (W. G. Hendrickson, T. Kusano, H. Yamaki, R. Balakrishnan, M. King, J. Murchie, and M. Schaechter, Cell 30:915-923, 1982). Of these three proteins, the 55-kDa protein was determined to be glycogen synthase on the basis of the N-terminal amino acid sequence and the molecular weight. The oriC complex was formed in glgA mutant cells, which produce no detectable glycogen, as well as in wild-type cells. None of the 35-, 55-, and 75-kDa proteins were detected in the fraction from this mutant. The results indicate that these proteins were not constituents of the oriC complex. 相似文献
42.
In the preceding paper, we suggested that 1 mol Ca(2+)-ATPase of sarcoplasmic reticulum (SR) contains 0.5 ml of high-affinity vanadate binding sites as well as 0.5 ml of low-affinity vanadate binding sites [Yamasaki, K. & Yamamoto, T. (1991) J. Biochem. 110, 915-921]. In the present study, we examined the effects of vanadate binding to the high- and low-affinity sites upon phosphorylation of the enzyme by inorganic phosphate (Pi). When vanadate was added to the reaction medium in which the Ca(2+)-ATPase had been phosphorylated by Pi in the absence of Ca2+, the steady-state level of phosphoenzyme (E2P) decreased due to inhibition of its formation. The decrease of E2P after addition of vanadate exhibited biphasic kinetics consisting of an initial fast decay process followed by a slower first-order decay process. The size of the fast E2P decay, which was estimated by extrapolating the slow phase decay to time 0, varied depending on the vanadate concentration with a dissociation constant of 17 microM, and reached maximum at 50 microM vanadate. The maximum value of the fast E2P decay was almost equal to the initial E2P level. The initial fast decay of E2P was competitively prevented by Pi with a dissociation constant of 7.4 mM, which was very close to Km for the E2P formation under similar conditions. These observations suggested that vanadate inhibits E2P formation by competition with Pi at a phosphorylation site on the Ca(2+)-ATPase. The slow first-order decay of E2P corresponded well to the vanadate binding to the high-affinity site of the Ca(2+)-ATPase.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
43.
H Bando T Sano T Ohshima C Y Zhang R Yamasaki K Matsumoto S Saito 《Endocrinologia japonica》1992,39(4):355-363
Plasma growth hormone (GH) responses to various stimuli were examined in 21 patients with GH-producing pituitary adenomas, classified into three types by the immunohistochemistry of cytokeratin and the glycoprotein hormone alpha-subunit distribution. Seven type 1 adenomas were exclusively composed of cells in which the cytokeratin formed a dot-like pattern; they were chromophobic to hematoxylin and eosin (H&E), occasionally positive for GH, and almost completely negative for the alpha-subunit. Thirteen type 2 adenomas were composed of cells with cytokeratin that had a perinuclear distribution; they were eosinophilic to H&E, and diffusely positive for both GH and the alpha-subunit. One patient had a type 3 adenoma which had a mixed pattern of intracellular cytokeratin distribution and was chromophobic and eosinophilic to H&E. Clinically, type 1 is characterized by earlier onset, larger tumor size, and more frequent aggressive extension. Paradoxical GH responses to TRH and OGTT were seen in 1 of 6 patients (16.7%) of type 1 and 8 of 9 patients (88.9%) of type 2, and 0% of type 1 and 62.5% of type 2, respectively. Type 2 cases showed higher plasma GH response to GH-releasing hormone, and a tendency to greater suppression of plasma GH by bromocriptine compared with type 1. Octreotide acetate administration revealed that the nadir/basal ratio of plasma GH levels was 42.9 +/- 6.6% in type 1 and 13.5 +/- 5.8% in type 2. These results suggest that there is a pathophysiological difference between these two distinct types of GH-producing pituitary adenomas. 相似文献
44.
A new behavioral mutant showing either head or body quivering, or both, was found in Japanese quail. This trait was characterized by neurofilament deficiency in the axons of the cervical spinal cord and the optic and sciatic nerves and was named "hypotrophic axonopathy." This character was shown to be controlled by an autosomal recessive gene, for which the gene symbol hax was proposed. 相似文献
45.
Eijiro Watanabe Masaaki Wachi Makari Yamasaki Kazuo Nagai 《Molecular & general genetics : MGG》1992,234(3):346-352
Summary The SopA, B, C genes of the F plasmid play an essential role in plasmid partitioning during cell division in Escherichia coli. In this paper, the products of the sopA and sopB genes were isolated and their biochemical activities studied. [-32P]ATP was cross-linked to the SopA protein by UV irradiation; this cross-linking was observed only in the presence of magnesium ion, and was competitively inhibited in the presence of non-radioactive ATP, ADP and dATP, but not other NTPs or dNTPs. In contrast, no ATP binding activity was detected for the SopB protein. The SopA protein showed a modest magnesium ion-dependent ATPase activity and this activity was stimulated in the presence of DNA. The ATPase activity in the presence of DNA was further stimulated by addition of the SopB protein. However, the SopB protein alone failed to stimulate the ATPase activity. 相似文献
46.
From the roots of Glycyrrhiza yunnanensis, collected in Yunnan, China, six new oleanane-type triterpene glycosides named yunganosides A1, B1, C1, D1, E2 and F2 were isolated together with hypaphorine. The structures of these glycosides were established by spectroscopic and chemical means. 相似文献
47.
Steroid saponins from Polygonatum kingianum. 总被引:13,自引:0,他引:13
Four new steroid saponins, kingianosides A-D, were isolated from the rhizome of Polygonatum kingianum, together with two known steroid saponins. On the basis of chemical and spectral evidence, the structures of kingianosides A-D were established as gentrogenin 3-O-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside, gentrogenin 3-O-beta-D-glucopyranosyl(1-->4)-beta-D-fucopyranoside, 26-O-beta-D-glucopyranosyl-22-hydroxy-25(R)-furost-5-en-12-on-3 beta, 22-diol 3-O-beta-D-glucopyranosyl(1-->4)-beta-D-galactopyranoside and 26-O-beta-D-glucopyranosyl-22-hydroxy-25(R)-furost-5-en-12-on-3 beta,22-diol 3-O-beta-D-glucopyranosyl(1-->4)-beta-D-fucopyranoside, respectively. 相似文献
48.
I Koshima S Soeda T Moriguchi H Higaki S Miyakawa M Yamasaki 《Plastic and reconstructive surgery》1992,89(4):710-714
Microvascular replantation at the distal phalangeal level has recently been reported by several authors, but as yet the rate of success has not been constant owing to the technical difficulties associated with small vessels. To solve this problem, over the last 4 years we have used arteriovenous anastomosis to reestablish either the arterial system or the venous drainage system in the 33 digits of our 23 patients. The results have been excellent, with a 91 percent success rate. Such results for replantation of the distal phalanx may be maintained and improved if a small venous graft with several branches is also utilized. 相似文献
49.
Molecular cloning of the protocatechuate 4,5-dioxygenase genes of Pseudomonas paucimobilis. 总被引:9,自引:8,他引:1
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Y Noda S Nishikawa K Shiozuka H Kadokura H Nakajima K Yoda Y Katayama N Morohoshi T Haraguchi M Yamasaki 《Journal of bacteriology》1990,172(5):2704-2709
We determined the nucleotide sequence of a 1.9-kilobase fragment of Pseudomonas paucimobilis SYK6 chromosomal DNA that included genes encoding protocatechuate 4,5-dioxygenase, the enzyme responsible for the aromatic ring fission of protocatechuate. Two open reading frames of 417 and 906 base pairs were found that had no homology with previously reported sequences, including those encoding protocatechuate 3,4-dioxygenase. Since both open reading frames were indispensable for the enzyme activity, they should encode the subunits of protocatechuate 4,5-dioxygenase. We named these genes ligA and ligB. Protocatechuate 4,5-dioxygenase was efficiently expressed in Escherichia coli with the aid of the lac promoter, and the polypeptides of the ligA and ligB gene products were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and amino acid sequencing. 相似文献
50.
Pathological examination of two 12-week-old male Sprague-Dawley rats revealed bending of the sternebrae. Grossly, the sternebrae distal to the third sternebra were bent towards the underside, and the episternal extremity was turned towards the head. Microscopically, the 4th sternebra was observed to have slipped behind the third sternebra, and fractures of the episternal cortex and slanting of the episternal cartilage were also observed. 相似文献