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11.
Hiroshi Ishii Osamu Nadaoka Yoshimasa Mimura Yoshio Inoue Riichir Chûj 《International journal of biological macromolecules》1989,11(6)
A tetrapetide containing an Aib residue, Boc-Asn-Aib-Thr-Aib-OMe, was synthesized as a peptide model for the N-glycosylation site in N-glycoproteins. Backbone conformation of the peptide and possible intramolecular interaction between the Asn and Thr side chains were elucidated by means of n.m.r. spectroscopy. Temperature dependence of NH proton chemical shift and NOE experiments showed that Boc-Asn-Aib-Thr-Aib-OMe has a tendency to form a β-turn structure with a hydrogen bond involving Thr and Aib4 NH groups. Incorporation of Aib residues in the peptide model promotes folding of the peptide backbone. With folded backbone conformation, carboxyamide protons of the Asn residue are not involved in hydrogen bond network, while the OH group of the Thr residue is a candidate for a hydrogen bond in DMSO-d6 solution. 相似文献
12.
Osamu Kondo Hiroyuki Honda Masahito Taya Takeshi Kobayashi 《Applied microbiology and biotechnology》1989,32(3):291-294
Summary Growth properties of carrot hairy root cells in various bioreactors were investigated. A turbine-blade reactor and an immobilized rotating drum reactor were found to be advantageous for the hairy root culture because of a high oxygen transfer coefficient (k in L a). After 30 days of culture, 10 g/l of dry hairy root cells were obtained in both bioreactors and maximum growth rates (V
m
) were found to be 0.63 and 0.61 g/l per day for the turbine-blade reactor and immobilized rotating drum reactor, respectively. Specific growth rates () at various cultivation times were observed to be linearly proportional to X/k
l
a for both bioreactor configurations where X is the cell concentration. The estimated specific oxygen uptake rate of 0.34 mmol O2/g dry cells per hour compares fairly well with an experimental value of 0.3. 相似文献
13.
Summary We found two types of hemoglobin, T and R, from the crab-eating macaque and compared those to A and Q previously reported. The 22 animals studied showed six different phenotypes, A, R, QA, QT, QAT, and QAR. Analysis of the complete amino acid sequences for the chains of hemoglobins Q, A, T, and R revealed that amino acids at four positions, 8, 55, 71, and 78 from the N-terminal, are variable. In the A chain, Thr, Val, Gly, and Gln occupy these positions, and in the Q chain the analogous amino acids are Thr, Val, Asp, and Gln, respectively. In the newly found T chain they are Thr, Val, Gly, and His; and in the R chain, they are Ser, Ile, Gly, and His, respectively. Two amino acids (8 Thr and 79 Gln) in A of the crab-eating macaque were found to be different from those in the chain of the Japanese macaque. 相似文献
14.
Solubilization and Characterization of Calcitonin Gene-Related Peptide Binding Site from Porcine Spinal Cord 总被引:1,自引:1,他引:0
Osamu Hiroshima Yoshihisa Sano Teruaki Yuzuriha Chiyuki Yamato Akira Saito Naomichi Okamura† Yasuo Uchiyama† Sadao Kimura † Katsutoshi Goto 《Journal of neurochemistry》1988,50(2):480-485
The binding site for calcitonin gene-related peptide (CGRP) was solubilized with 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate (CHAPS) in an active form from porcine spinal cord. 125I-labeled human alpha-CGRP (125I-CGRP) binding to the solubilized protein was determined by filtration using a GF/B glass filter. The maximal binding activity (approximately 60% of the crude membrane fraction) was obtained with 5 mM CHAPS. 125I-CGRP binding to the solubilized protein was of high affinity, saturability, and high specificity, having KD and Bmax values of 3.69 pM and 338 fmol/mg of protein, respectively. The binding activity was eluted in a single peak with a molecular mass of 400,000 daltons by gel filtration on TSK gel G4000SW. These results suggest that the solubilized protein may be responsible for the specific binding site. 相似文献
15.
The leaf ultrastructure of NADP-malic enzyme type C4 species possessing different anatomical features in the Cyperaceae was examined: types were the Rhynchosporoid type, a normal
Kranz type in which mesophyll cells are adjacent to Kranz cells, and Fimbristyloid and Chlorocyperoid types, unusual Kranz
types in which nonchlorophyllous mestome sheath intervenes between the two types of green cells. They show structural characteristics
basically similar to the NADP-malic enzyme group of C4 grasses, that is, centrifugally located chloroplasts with reduced grana and no increase of mitochondrial frequency in the
Kranz cells. However, the Kranz cell chloroplasts of the Fimbristyloid and Chlorocyperoid types exhibit convoluted thylakoid
systems and a trend of extensive development of peripheral reticulum, although those of the Rhynchosporoid type do not possess
such particular membrane systems. The suberized lamella, probably a barrier for CO2 diffusion, is present in the Kranz cell walls of the Rhynchosporoid type and in the mestome sheath cell walls of the other
two types, and tightly surrounds the Kranz cells (sheaths) that are the sites of the decarboxylation of C4 acids. These ultrastructural features are discussed in relation to C4 photosynthetic function. 相似文献
16.
Immunohistochemical localization of Na+-dependent glucose transporter in rat jejunum 总被引:2,自引:0,他引:2
Kuniaki Takata Toshiko Kasahara Michihiro Kasahara Osamu Ezaki Hiroshi Hirano 《Cell and tissue research》1992,267(1):3-9
Summary Glucose is actively absorbed via a Na+-dependent active glucose transporter (Na-GT) in the small intestine. We raised a polyclonal antibody against the peptide corresponding to amino acids 564–575 of rabbit intestinal Na-GT, and localized it immunohistochemically in the rat jejunum. By means of immunofluorescence staining, Na-GT was located at the brush border of the absorptive epithelial cells of the intestinal villi. Electron-microscopic examination showed that Na-GT was localized at the plasma membrane of the apical microvilli of these cells. Little Na-GT was found at the basolateral plasma membrane. Along the crypt-villus axis, all of the absorptive epithelial cells in the villus were positive for Na-GT. In addition to the brush border staining, the supranuclear positive staining, which was shown to be the Golgi apparatus by use of electron microscopy, was seen in cells located between the base to the middle of the villus. Cells in crypts exhibited little or no staining for Na-GT. Goblet cells scattered in the intestinal epithelium were negative for Na-GT staining. These observations show that Na-GT is specific to the apical plasma membrane of the absorptive epithelial cells, and that the onset of Na-GT synthesis may occur near the crypt-villus junction. 相似文献
17.
18.
Hidenori Shinkawa Masanori Sugiyama Yuji Hatada Takeshi Ohuchi Masao Udagawa Osamu Nimi 《Biotechnology letters》1991,13(8):537-542
Summary The bald mutants from streptomycin (SM)-producingStreptomyces griseus 2247 obtained by incubation at high temperature (36° C), designated as HT strains, lost resistance to their own antibiotic and scarcely produced the antibiotic. Although SM susceptibility in the mutant was due to loss of SM 6-phosphotransferase activity produced in the cell, the gene coding for the enzyme cloned from an HT strain was surely expressed inS. lividans 1326 as a host. Northern blot analysis showed that the corresponding RNA is not detected in the mutant, indicating that though the gene encoding SM 6-phosphotransferase, at least, the structural gene is not deleted in the cell, the expression is silent. 相似文献
19.
Endothelin stimulates c-fos and c-myc expression and proliferation of vascular smooth muscle cells 总被引:51,自引:0,他引:51
Recently, a potent vasoconstrictor peptide, endothelin (EDT), was isolated from vascular endothelial cells. We examined its effect on rat vascular smooth muscle cells (VSMCs). EDT induced the elevation of intracellular calcium, which was dependent on extracellular calcium and inhibited by a calcium-channel antagonist in a competitive manner. EDT caused a rapid and transient increase in the c-fos and c-myc mRNA levels and stimulated the DNA synthesis of VSMCs in a dose-dependent manner. This effect of EDT on the proliferation of VSMCs might be related to the development of atherosclerosis. 相似文献
20.
Developmentally regulated alternative splicing of brain myelin-associated glycoprotein mRNA is lacking in the quaking mouse 总被引:5,自引:0,他引:5
Evidence is presented that expression of the two myelin-associated glycoprotein mRNAs is developmentally regulated in mouse brain. In quaking mouse, the mRNA without a 45-nucleotide exon portion was scarcely expressed throughout development. We conclude that the mechanism of splicing out the 45-nucleotide exon portion is lacking in quaking mouse. 相似文献