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81.
Koichi Mitsukura Tatsuya Kuramoto Toyokazu Yoshida Norihiro Kimoto Hiroaki Yamamoto Toru Nagasawa 《Applied microbiology and biotechnology》2013,97(18):8079-8086
A NADPH-dependent (S)-imine reductase (SIR) was purified to be homogeneous from the cell-free extract of Streptomyces sp. GF3546. SIR appeared to be a homodimer protein with subunits of 30.5 kDa based on SDS-polyacrylamide gel electrophoresis and HPLC gel filtration. It also catalyzed the (S)-enantioselective reduction of not only 2-methyl-1-pyrroline (2-MPN) but also 1-methyl-3,4-dihydroisoquinoline and 6,7-dimethoxy-1-methyl-3,4-dihydroisoquinoline. Specific activities for their imines were 130, 44, and 2.6 nmol?min?1?mg?1, and their optical purities were 92.7 % ee, 96.4 % ee, and >99 % ee, respectively. Using a NADPH-regenerating system, 10 mM 2-MPN was converted to amine with 100 % conversion and 92 % ee after 24 h. The amino acid sequence analysis revealed that SIR showed about 60 % identity to 6-phosphogluconate dehydrogenase. However, it showed only 37 % identity with Streptomyces sp. GF3587 (R)-imine reductase. Expression of SIR in Escherichia coli was achieved, and specific activity of the cell-free extract was about two times higher than that of the cell-free extract of Streptomyces sp. GF3546. 相似文献
82.
83.
Tatsuya Kawamoto Yoshifumi Kobayashi Hidenori Nakajima Yukiko Yamagishi 《Biochemical and biophysical research communications》2013
Vascular network formation is a key therapeutic event in regenerative medicine because it is essential for mitigating or ameliorating ischemic conditions implicated in various diseases and repair of tissues and organs. In this study, we induced human induced pluripotent stem cells (hiPSCs) to differentiate into heterogeneous cell populations which have abilities to form vascular vessel-like structures by recapitulating the embryonic process of vasculogenesis in vitro. These cell populations, named cardiovascular blast populations (CBPs) in this report, primarily consisted of CD31+ and CD90+ cells. 相似文献
84.
Keiichi Konoki Tatsuya Onoda Sachie Furumochi Yuko Cho Mari Yotsu-Yamashita Takeshi Yasumoto 《Bioorganic & medicinal chemistry letters》2013,23(21):5833-5835
The binding between [24-3H]okadaic acid (OA) and a recombinant OA binding protein OABP2.1 was examined using various OA analog, including methyl okadaate, norokadanone, 7-deoxy OA, and 14,15-dihydro OA, 7-O-palmitoyl DTX1, to investigate the structure activity relationship. Among them, 7-O-palmitoyl DTX1, which is one of the diarrhetic shellfish poisoning (DSP) toxins identified in shellfish, displayed an IC50 for [24-3H]OA binding at 51 ± 6.3 nM (Mean ± SD). In addition, a synthetic compound, N-pyrenylmethyl okadamide, exhibited its IC50 at 10 ± 2.9 nM (Mean ± SD). These results suggested that the recombinant OABP2.1 and the N-pyrenylmethyl okadamide might be core substances in a novel assay for the DSP toxins. 相似文献
85.
86.
Masao Fujimaki Makoto Tajima Teruyo Matsumoto 《Bioscience, biotechnology, and biochemistry》2013,77(10):1228-1231
The free amino acids of potatoes irradiated with the doses of 7,000, 15,000 and 30,000 rad were determined by ion-exchange chromatography.After 15 days storage following irradiation, it was shown that the concentration of asparatic acid, proline and aliphatic amino acids increased with increasing irradiation doses, while that of basic amino acids and glutamic acid especially decreased. However, after 105 days of storage, the similarity of the free amino acid content of irradiated potatoes to that of non-irradiated and non-stored potatoes was observed.On the concentration of protein-bound amino acids, there were no significant differences between non-irradiated and 15,000 rad irradiated potatoes. 相似文献
87.
Makoto Tajima Suzue Tadokoro-Yasui Tadanao Suzuki Kuniko Shinoda-Kenmochi Taeko Kitano Keiko Tsuchiya 《Bioscience, biotechnology, and biochemistry》2013,77(10):1949-1952
Lactobacillus brevis and Saccharomyces cerevisiae were completely sterilized by the supercritical (SC) CO2 micro-bubble method. Gaseous (G) and liquid (LQ) CO2 were used in a similar manner to compare the sterilizing effect. Among the three treatments, the microorganisms were only effectively sterilized by the SC CO2 treatment at 25 MPa and 35°C. 相似文献
88.
Cell protein isolates were prepared from yeast (S. cerevisiae) by alkali-extraction followed by acid precipitation. The relationships between alkali-treatment and nucleic acid contents in cell protein isolates were examined.The isolate which was precipitated at pH 4.5 following extraction with 0.20 n NaOH at 80°C contained small amounts (less than 1 % of the isolate) of nucleic acids. However, the content of nucleotides in the isolate which was precipitated at pH 4.5 following extraction with 0.20 n NaOH at 37°C was 9.13% of the product. Treatment by washing or dialysis of the isolate had little effect in removing the nucleotides in the isolate.This finding was explained by the interaction of nucleotide to cell protein isolate. The binding energy was measured by Hummel’s method. 相似文献
89.
Tatsuya Kawato Eiichi Mizohata Yohei Shimizu Tomohiro Meshizuka Tomohiro Yamamoto Noriaki Takasu 《Bioscience, biotechnology, and biochemistry》2013,77(4):640-642
The streptavidin/biotin interaction has been widely used as a useful tool in research fields. For application to a pre-targeting system, we previously developed a streptavidin mutant that binds to an iminobiotin analog while abolishing affinity for natural biocytin. Here, we design a bivalent iminobiotin analog that shows 1000-fold higher affinity than before, and determine its crystal structure complexed with the mutant protein. 相似文献
90.
Makoto Tajima Makio Morita Masao Fujimaki 《Bioscience, biotechnology, and biochemistry》2013,77(9):1277-1281
When 10?3m cysteine solution was irradiated in the presence of glucose at the concentration of ten-fold of cysteine, the G-values of products produced from cysteine were similar to those from 10?3m cysteine solution. On the other hand, the yield of carbonyl compound from glucose was suppressed completely by interaction between cysteine and radicals which are secondarily produced from glucose.Methionine could not suppress the yield of carbonyl compound from glucose, and, G-values of products from methionine varied in comparison with those from solution containing methionine only.From the results using scavenger, it was concluded that oxidation to methionine sulfoxide and cleavage to α-aminobutyric acid was caused by OH and attack, respectively. 相似文献