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21.
Takehiko?Yokoyama Yumiko?Tanaka Minoru?Sato Nobuhiro?Kan-No Toshiki?Nakano Toshiyasu?Yamaguchi Eizoh?NagahisaEmail author 《Fisheries Science》2005,71(4):924-930
ABSTRACT: In this paper, the authors report the detection of alanine racemase activity in the marine diatom Thalassiosira sp. Since the Thalassiosira sp. was cultured under germ-free conditions, it appeared that D-alanine was not derived from bacteria but was produced through catalysis by algal alanine racemase. The rate of conversion of L-alanine to D-alanine was approximately the same as that for the reverse reaction, and the enzyme catalyzed the equilibration of the D- and L-forms. The crude enzyme preparation obtained from the cells at the stationary phase of the growth cycle had an optimal pH of approximately 9.5. The Lineweaver–Burk analysis showed that the K m for D- and L-alanine was 16.5 mM and 29.4 mM, respectively. It appears that the enzyme is highly specific for D- or L-alanine because it does not catalyze the racemization of other amino acids. In addition, after gel filtration, the enzyme did not require exogenous pyridoxal 5'-phosphate (PLP) for its activity, however, the effects of several chemicals suggest that the enzyme may be PLP-dependent. The enzyme is more similar to that found in invertebrates when compared with that found in bacteria. This is the first report on the occurrence of alanine racemase activity in the microalga Thalassiosira sp. 相似文献
22.
Takanori Yamazaki Toshiki Ishikawa Ganesh N. Pandian Keiichi Okazaki Kohsuke Haginoya Yuka Tachikawa Toshiaki Mitsui Kazuhisa Miyamoto Chanan Angusthanasombat Hidetaka Hori 《Pesticide biochemistry and physiology》2011,101(2):125-131
Midgut juice of Plutellaxylostella strain PXR which is resistant to Cry1Ac was biochemically characterized relative to the susceptible PXS strain. The midgut juice of PXR (PXR-Juice) was shown to process Cry1Ac protoxin to 60 kDa active toxin with the same processing pattern as that of juice from PXS (PXS-Juice) in SDS–PAGE. PXS larvae which were given the Cry1Ac toxin pre-processed with PXR-Juice were killed with the same rate as that with Cry1Ac pre-activated by trypsin. PXR-Juice was found to contain three times larger amount of 66 kDa protein (P66) than PXS-Juice and the N-terminal amino acid sequence of P66 was matched to that of glucosinolate sulfatase in data base search. The protein band of P66 was coincided with the band of p-nitro phenyl sulfatase activity in zymogram. P66 purified to homogeneity in SDS-PAGE bound to Cry1Ac and soybean agglutinin, and KD for Cry1Ac was estimated to be 718 nM with surface plasmon resonance analysis. Using purified sulfatase, Km and Vmax were estimated and involvement of the enzyme in the PXR resistance was discussed. 相似文献
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Akira Yamamoto Akira Iwata Toshiki Saitoh Kotaro Tuchiya Tomoko Kanai Hajime Tsujimoto Atsuhiko Hasegawa Akira Ishihama Susumu Ueda 《Veterinary immunology and immunopathology》2002,90(3-4)
Feline granulocyte colony-stimulating factor (G-CSF) with an N-terminal histidine hexamer tag was expressed as inclusion bodies in E. coli. The G-CSF solubilized in 6 M guanidine solution was absorbed onto a Ni-NTA column and, after washing with decreasing concentrations of guanidine, eluted with imidazole in a soluble and apparently pure form. The activity of the recombinant feline G-CSF was 3×106 U/mg protein, as assayed by its stimulatory effect on NFS-60 cell proliferation. When a low level of purified feline G-CSF was administered once a day for two successive days to cats, the number of neutrophil increased 4-fold while the levels of other blood cell types remained virtually unchanged. Daily administration of G-CSF for a total of 11 days led to a more than 10-fold increase in neutrophils, an 8-fold increase in the number of monocytes and 2-fold increase in lymphocytes. No severe side effects or antibody production was observed in cats after administration of G-CSF. 相似文献
25.
Masahiro Hatamoto Ryo Aizawa Kogomi Koda Toshiki Fukuchi 《Journal of Pesticide Science》2021,46(2):198
Aminopyrifen is a novel 2-aminonicotinate fungicide with unique chemistry and a novel mode of action. The fungicide showed high antifungal activity mainly against Ascomycetes and its related anamorphic fungi under in vitro and pot conditions (EC50 values: 0.0039–0.23 mg/L and 1.2–12 mg/L, respectively). The active ingredient strongly inhibited germ-tube elongation of Botrytis cinerea below 0.1 mg/L and invasion into a plant. The compound exhibited no cross-resistance to commercial fungicides in B. cinerea. The antifungal agent showed high preventive efficacy and translaminar action. In the field, aminopyrifen controlled gray mold and powdery mildew at 150 mg/L. Our findings suggest that aminopyrifen is useful for protecting crops from various plant pathogens. 相似文献
26.
Zhihua Tao Minoru Sato Kegang Wu Hiromasa Kiyota Toshiyasu Yamaguchi Toshiki Nakano 《Fisheries Science》2012,78(4):923-926
We established a simple, rapid method for gizzerosine analysis in fish meal. Gizzerosine was extracted from fish meal with 0.1?N HCl solution. Samples and standard gizzerosine solutions were absorbed onto a paper disc, which was then set on electrophoresis paper for 18?min, and the paper was dried. Gizzerosine was visualized with Pauly??s reagent, and the intensity of the colored spots was digitized and calculated by image processing method software. We achieved successful separation of gizzerosine from other Pauly??s reagent-positive components in fish meal extracts. The linearity of gizzerosine estimation using this method was within the range 30?C1000?ng (R 2?=?0.99). Gizzerosine was satisfactorily detected and completely separated from histamine and other Pauly??s reagent-positive compounds. This method does not require expensive instruments or tedious pretreatment to eliminate interfering compounds, such as histamine or histidine. It also uses less reagent compared with high-performance liquid chromatography. Moreover, it is a simple, rapid, sensitive, and reproducible method. It is suitable for monitoring gizzerosine in fish meal products that contain as little as 10?ppm gizzerosine. 相似文献
27.
Enzymatic saccharifications of the hydrolysate collected as the water-soluble (WS) portion after hot-compressed water (HCW)
treatment of Japanese beech with xylanase and β-xylosidase were performed to investigate the hydrolytic properties of these enzymes. The WS portions with different molecular
weight distributions and initial concentrations of xylooligosaccharides were prepared as substrates, one of which contained
mainly smaller xylooligosaccharides [degree of polymerization (DP) = 2 or 3], while the other contained larger xylooligosaccharides
(DP ≥ 4). The highest xylose recovery was obtained from both of the WS portions treated with β-xylosidase rather than with xylanase. This suggests that β-xylosidase could have a higher activity than xylanase toward larger xylooligosaccharides (DP ≥ 4) as well as smaller xylooligosaccharides
(DP = 2 or 3) recovered from HCW treatment. As a result, the use of β-xylosidase was found to be effective for saccharifi cation of the WS portion, even with a short reaction time for the HCW
treatment. 相似文献
28.
Akira Yamamoto Akira Iwata Toshiki Saito Fumiko Watanabe Susumu Ueda 《Veterinary immunology and immunopathology》2009,130(3-4):221-225
Canine granulocyte colony-stimulating factor (cG-CSF) with modification of cysteine at position 17 to serine was expressed in Brevibacillus choshinensis HPD31. cG-CSF secreted into the culture medium was purified by ammonium sulfate precipitation and consecutive column chromatography, using butyl sepharose and DEAE sepharose. Biological activity of the recombinant cG-CSF was 8.0 × 106 U/mg protein, as determined by its stimulatory effect on NFS-60 cell proliferation. Purified cG-CSF was subcutaneously administered once a day for two successive days to dogs (1, 5, 25, or 125 μg). Neutrophil count increased the following day in all dogs except those administered the lowest dose (1 μg). No severe side effects were observed in dogs after administration of cG-CSF. 相似文献
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Noritake K Matsuoka T Ohsawa T Shimomura K Sanbuissho A Uenoyama Y Maeda K Tsukamura H 《The Journal of reproduction and development》2011,57(3):409-415
It has recently been shown that neurokinin B, a tachykinin, is associated with GnRH pulse generation in sheep and goats. The aim of the present study was to clarify the role of tachykinin receptors in the control of LH secretion in rats. To this end, we evaluated the effect of CS-003, an antagonist for all three neurokinin receptors (NK1, NK2 and NK3 receptors), on pulsatile LH secretion in both sexes of rats with different routes of administration. Both oral and third ventricular administration of CS-003 suppressed LH secretion in both sexes of gonadectomized animals. Furthermore, intact male rats with oral administration of CS-003 showed decreased serum testosterone levels, which might be due to suppressed LH secretion. None of the three subtype-specific neurokinin receptor antagonists showed a significant effect on LH secretion in ovariectomized rats when each antagonist was singly administered. The present results suggest that neurokinins play a role in the control of pulsatile GnRH/LH secretion via multiple neurokinin receptors in both male and female rats. 相似文献