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41.
Masayuki Sakakibara Kenji Mori Masanao Matsui 《Bioscience, biotechnology, and biochemistry》2013,77(10):1825-1827
Several microorganisms capable of utilizing 1-aminocyclopropane-1-carboxylate (ACPC) were isolated from soil. A bacterium which belongs to Pseudomonas accumulated cellular α-aminobutyrate with consumption of ACPC and cells incubated with ACPC medium had the activity deaminating the substrate to form α-ketobutyrate. An enzyme, ACPC deaminase, was highly purified and its molecular weight, substrate specificity and absorption spectrum were investigated. These results suggested that this enzyme was a pyridoxal 5′-phosphate enzyme which has the molecular weight of 104000 and high specificity for ACPC, Km= 1.5 mM. A yeast, Hansenula saturnus, is also capable of forming ACPC deaminase, which has a lower molecular weight, 69000, and higher Km value, 2.6 mM. 相似文献
42.
Kenji Mori Masanao Matsui Yusuke Sumiki 《Bioscience, biotechnology, and biochemistry》2013,77(3):205-222
In order to clarify the structure of ring A of gibberellins, thirteen lactones of cyclohexan series, of which eight were new, were prepared to examine their infrared spectra. So far; the experiment is concerned, γ-lactones show the characteristic absorption band in the rang 1775~1782 cm?1 in dioxane, while 5-ones in the range 1730/~1762 cm?1. Since the absorptio band due to lactone carbonyl of gibberellins occurs at the range 1777~1786 cm?1 in dioxane, the lactone ring of gibberellins seems to be γ. 相似文献
43.
Nobuyoshi Esaki Hidehiko Tanaka Edith Wilson Miles Kenji Soda 《Bioscience, biotechnology, and biochemistry》2013,77(12):2861-2864
The α2β2 complex of tryptophan synthase from Escherichia coli catalyzes β-replacement reactions of l-serine and its derivatives (e.g., β-chloro-l-alanine and O-methyl-Dl-serine) with various alkanethiols. The products from thiobenzyl alcohol and ethanethiol were isolated to demonstrate the enzymatic synthesis of the corresponding S-substituted l-cysteines. Reactivities of various S-substituent donors were examined, and thiols such as thiobenzyl alcohol, 1-propanethiol and 1-butanethiol were found to be much more efficient substituent donors than the physiological substrate, indole. In addition, tryptophan synthase catalyzes β-replacement reactions of l-threonine with thiols to form the corresponding S-substituted β-methylcysteines, which are also produced by β-addition reactions of l-vinylglycine with thiols. These enzymatic reactions facilitate the synthesis of various sulfur-containing amino acids. 相似文献
44.
Kenji Mori 《Bioscience, biotechnology, and biochemistry》2013,77(13):2519-2522
Stereochemistry at C–16 of dihydrogibberellin A1 methyl ester (methyl tetrahydrogib-berellate, III) and its 16-epimer was elucidated. NMR analysis employing a shift reagent, Eu(thd)3 or Eu(fod)3, was found to be very effective for settling this stereochemical problem. 相似文献
45.
Critical examinations were made on the conditions for preparing the sugar solutions to be analyzed by ion-exchange chromatography of sugar-borate complexes by the method of Khym and Zill. A procedure was proposed which gave the best recovery of sugars with minimum hydrolysis of sucrose. By means of this procedure, sugar solutions were prepared from potato tubers which had been stored at a high (30°C) or low temperature (6°C). Results of the chromatographic separation and determination of component sugars showed that main sugars present in potato tubers were sucrose, glucose, and fructose. Maltose and pentoses could not be detected. The contents of sucrose, glucose, and especially, fructose were far greater in potatoes stored at a low temperature than in those stored at a high temperature. 相似文献
46.
Kenji Aoki Motoo Arai Yasuji Minoda Koichi Yamada 《Bioscience, biotechnology, and biochemistry》2013,77(12):1913-1920
The Acid-stable α-amylase and the acid-unstable α-amylase from Aspergillus niger contained one mole of sulfhydryl group per one mole of enzyme, which probably existed correlating with calcium atom that was essential for the amylase activity.Iodine reacted at acidic pH specifically with the sulfhydryl group of both enzymes and oxidized it to considerably high degree, since about 4 eq of iodine per mole of sulfhydryl group of both enzymes were consumed. The modification of the sulfhydryl group of the acid-stable α-amylase did not affect the amylase acitvity, while, that of the acid-unstable α-amylase reduced it to 70 per cents intact enzyme. It was difficult to carry out carboxy-methylation of the sulfhydryl group of the acid-stable α-amylase under mild conditions maintaining its activity, but that of the acid-unstable α-amylase was easily achieved.These facts suggested that some differences existed in the neighborhood of the sulfhydryl group of both enzymes, and that the sulfhydryl group of them was not the active site. 相似文献
47.
Data are presented to show the gas chromatographic identification of a total of 18 saturated aliphatic γ- and δ-lactones obtained from melted beef depot fat, namely, δ-C6, γ-C7, γ-C8, γ-C9, and a homologous series of γ- and δ-lactones of the even-carbon numbers C10 to C16 and of smaller amount of the odd-carbon numbers C11 to C15. These lactones were isolated by steam distillation and silicic acid adsorption chromatography, and identified through gas chromatography and infrared spectroscopy.Lactones obtained had a peach-like flavor, and it was suggested that lactones were important in heated beef fat as the flavor compounds. 相似文献
48.
Kenji Kobata Ikue Takemura Gaku Tago Takayuki Moriya Kaori Kubota Sachie Nakatani 《Bioscience, biotechnology, and biochemistry》2013,77(7):1242-1245
Long-chain N-vanillyl-acylamides (LCNVAs) were generated from plant oils and vanillylamine (VA) by nucleophilic amidation without any catalytic reagents. The resulting LCNVAs varied according to the fatty acid composition of the plant oil used. Therefore, the LCNVAs contained in Capsicum oleoresins were products that were spontaneously generated from the oleoresin during storage. 相似文献
49.
Hiroyasu Kawai Kenji Yamamoto Akira Kimura Tatsurokuro Tochikura 《Bioscience, biotechnology, and biochemistry》2013,77(7):1741-1743
An E. coli strain, SH209, harboring pLC9–12 exhibited 5- to 6-fold higher γ-glutamyltranspeptidase activity than the wild-type strain, at each growth temperature tested. Maximum activity was observed at 20 ~ 25°C, as was observed with the wild type. A homogeneous enzyme preparation was obtained from the periplasmic fraction of the strain by a simple three-step method. The conditions for γ-glutamyl-DOPA synthesis from l-glutamine and l-DOPA were investigated using the enzyme preparation. Under the best conditions, the maximal yield of 79%, equivalent to 158 mm (51.5 g/l) of γ-glutamyl-DOPA as to both substrates, was obtained. γ-Glutamyl-DOPA was isolated from the reaction mixture and identified using an amino acid analyzer after hydrolysis with HCl or γ-glutamyltranspeptidase. 相似文献
50.
Kohei Fujikura Tomiyoshi Setsu Kenji Tanigaki Takaya Abe Hiroshi Kiyonari Toshio Terashima Toshiaki Sakisaka 《PloS one》2013,8(1)
We describe a novel spontaneous mouse mutant, laggard (lag), characterized by a flat head, motor impairment and growth retardation. The mutation is inherited as an autosomal recessive trait, and lag/lag mice suffer from cerebellar ataxia and die before weaning. lag/lag mice exhibit a dramatic reduction in brain size and slender optic nerves. By positional cloning, we identify a splice site mutation in Kif14. Transgenic complementation with wild-type Kif14-cDNA alleviates ataxic phenotype in lag/lag mice. To further confirm that the causative gene is Kif14, we generate Kif14 knockout mice and find that all of the phenotypes of Kif14 knockout mice are similar to those of lag/lag mice. The main morphological abnormality of lag/lag mouse is severe hypomyelination in central nervous system. The lag/lag mice express an array of myelin-related genes at significantly reduced levels. The disrupted cytoarchitecture of the cerebellar and cerebral cortices appears to result from apoptotic cell death. Thus, we conclude that Kif14 is essential for the generation and maturation of late-developing structures such as the myelin sheath, cerebellar and cerebral cortices. So far, no Kif14-deficient mice or mutation in Kif14 has ever been reported and we firstly define the biological function of Kif14 in vivo. The discovery of mammalian models, laggard, has opened up horizons for researchers to add more knowledge regarding the etiology and pathology of brain malformation. 相似文献