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Characterization of Fusarium oxysporum β-1,6-Galactanase, an Enzyme That Hydrolyzes Larch Wood Arabinogalactan 下载免费PDF全文
Tatsuji Sakamoto Yuya Taniguchi Shiho Suzuki Hideshi Ihara Haruhiko Kawasaki 《Applied microbiology》2007,73(9):3109-3112
A type II arabinogalactan-degrading enzyme (FoGal1) was purified from Fusarium oxysporum 12S, and the corresponding cDNA was isolated. FoGal1 had high similarity to enzymes of glycoside hydrolase family 5. Treatment of larch wood arabinogalactan with the recombinant enzyme indicated that FoGal1 is a β-1,6-galactanase that preferentially debranches β-1,6-galactobiose from the substrate. 相似文献
73.
Gliding motility of Mycoplasma mobile can occur by repeated binding to N-acetylneuraminyllactose (sialyllactose) fixed on solid surfaces 下载免费PDF全文
Mycoplasma mobile relies on an unknown mechanism to glide across solid surfaces including glass, animal cells, and plastics. To identify the direct binding target, we examined the factors that affect the binding of Mycoplasma pneumoniae to solid surfaces and concluded that N-acetylneuraminyllactose (sialyllactose) attached to a protein can mediate glass binding on the basis of the following four lines of evidence: (i) glass binding was inhibited by N-acetylneuraminidase, (ii) glass binding was inhibited by N-acetylneuraminyllactose in a structure-dependent manner, (iii) binding occurred on glass pretreated with bovine serum albumin attached to N-acetylneuraminyllactose, and (iv) gliding speed depended on the density of N-acetylneuraminyllactose on glass. 相似文献
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A proteolytic enzyme was purified from Xenopus embryos. The purification procedure consisted of fractionation of an extract of embryos with acetone, gel filtration of Sephadex G-75 and chromatography on carboxymethyl-cellulose and hydroxylapatite. The preparation of enzyme appeared to be homogeneous as judged by electrophoresis in polyacrylamide gels. This protease had a molecular mass of 43-44 kDa and was composed of two subunits with molecular masses of 30 kDa and 13 kDa. The optimal pH of the reaction catalysed by the protease was approximately 4.0. This proteolytic activity was inhibited by antipain, leupeptin and iodoacetic acid; it was not affected by phenylmethylsulfonyl fluoride and pepstatin; and it was enhanced by dithiothreitol. In the presence of RNA, the optimal pH was shifted from pH 4.0 to pH 4.5. The protease was activated by addition of total RNA from Xenopus embryos, by poly(rU) or poly(rG). In contrast, after addition of tRNA or poly(rC), no activation of the protease was observed. 相似文献
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Masaki Mizutani Isil Tulum Yoshiaki Kinosita Takayuki Nishizaka Makoto Miyata 《Biophysical journal》2018,114(6):1411-1419
Mycoplasma mobile is a bacterium that uses a unique mechanism to glide on solid surfaces at a velocity of up to 4.5 μm/s. Its gliding machinery comprises hundreds of units that generate the force for gliding based on the energy derived from ATP; the units catch and pull sialylated oligosaccharides fixed to solid surfaces. In this study, we measured the stall force of wild-type and mutant strains of M. mobile carrying a bead manipulated using optical tweezers. The strains that had been enhanced for binding exhibited weaker stall forces than the wild-type strain, indicating that stall force is related to force generation rather than to binding. The stall force of the wild-type strain decreased linearly from 113 to 19 picoNewtons after the addition of 0–0.5 mM free sialyllactose (a sialylated oligosaccharide), with a decrease in the number of working units. After the addition of 0.5 mM sialyllactose, the cells carrying a bead loaded using optical tweezers exhibited stepwise movements with force increments. The force increments ranged from 1 to 2 picoNewtons. Considering the 70-nm step size, this small-unit force may be explained by the large gear ratio involved in the M. mobile gliding machinery. 相似文献
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Hitotsuyanagi Y Lee JE Kato S Kim IH Kohashi H Fukaya H Takeya K 《Bioorganic & medicinal chemistry》2011,19(7):2458-2463
Penta-N-methyl and hexa-N-methyl analogues of RA-VII, an antitumor bicyclic hexapeptide of plant origin, were prepared. In the former, the nitrogens of d-Ala-1 and Ala-4 and in the latter, those of d-Ala-1, Ala-2, and Ala-4 were methylated under the phase-transfer catalysis conditions. Their solution structures were established by NOESY experiments and the crystal structures by X-ray crystallography. Those two methylated analogues showed much weaker cytotoxicity against P-388 leukemia cells than the parent RA-VII. 相似文献
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Burioka N Takata M Okano Y Ohdo S Fukuoka Y Miyata M Takane H Endo M Suyama H Shimizu E 《Chronobiology international》2005,22(3):585-590
We determined whether human peripheral blood mononuclear cells (PBMCs) could be used to analyze clock genes by studying their mRNA expressions in human bronchial epithelium (BEAS-2B) and PBMCs following stimulation by the glucocorticoid homologue dexamethasone (DEX) in vitro. PBMCs were obtained at 10:00 h from two diurnally active (∼07:00 to 23:00 h) healthy volunteers and were evaluated for hPer1 mRNA expression following DEX stimulation in vitro using real time-PCR analysis. DEX stimulation of human BEAS-2B cells and PBMCs in vitro led to a remarkable increase of hPer1 mRNA. The glucocorticoid rapidly affected the expression of hPer1 mRNA in PBMCs, suggesting that human PBMCs may be a useful surrogate marker for the investigation of drug effects on clock genes. 相似文献
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