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41.
Specific isolation of N-terminal fragments from proteins and their high-fidelity de novo sequencing 总被引:1,自引:0,他引:1
Yamaguchi M Obama T Kuyama H Nakayama D Ando E Okamura TA Ueyama N Nakazawa T Norioka S Nishimura O Tsunasawa S 《Rapid communications in mass spectrometry : RCM》2007,21(20):3329-3336
A new method to determine N-terminal amino acid sequences of multiple proteins at low pmol level by a parallel processing has been developed. The method contains the following five steps: (1) reduction, S-alkylation and guanidination for targeted proteins; (2) coupling with sulfosucccimidyl-2-(biotinamido)ethyl-1,3-dithiopropionate(sulfo-NHS-SS-biotin) to N(alpha)-amino groups of proteins; (3) digestion of the modified proteins by an appropriate protease; (4) specific isolation of N-terminal fragments of proteins by affinity capture using the biotin-avidin system; (5) de novo sequence analysis of peptides by MALDI-TOF-/MALDI-TOF-PSD mass spectrometry with effective utilization of the CAF (chemically assisted fragmentation) method.1 This method is also effective for N-terminal sequencing of each protein in a mixture of several proteins, and for sequencing components of a multiprotein complex. It is expected to become an essential proteomics tool for identifying proteins, especially when used in combination with a C-terminal sequencing method. 相似文献
42.
Shigeyama M Ohgaya O Takeuchi H Hino T Kawashima Y 《Chemical & pharmaceutical bulletin》2001,49(2):129-133
We intended to develop a desired ointment base suitable for treatment of bedsores including the proliferation of granulation and epidermis. The main bedsore bacteria detected in our hospital were S. aureus in gram-positive coccus and P. aeruginosa in gram-negative bacillus. As the macrogol ointment (MO) was found to have bactericidal effects on these bacteria, MO was adopted as the base for the objective ointment. To improve the properties of the ointment base such as regulating the humidity of the exudation and controlling the release of antibiotics formulated in the ointment, co-formulating effects of various additives to MO were evaluated. The sustained release function of the ointment base was obtained by adding hydrophilic petrolatum (HP) to MO. However, the resultant ointment was found to have a poor humidity regulating property. On the other hand, MO containing 5% of hydroxypropyl cellulose (HPC) showed both the humidity regulating and the controlled drug releasing properties. It was considered that HPC particles dispersed in the ointment could be swelled by absorbing water to form a gel network. The curd tension meter tests for the ointments prepared with the various polymers showed that the MO-HPC base, which showed the highest sustained drug releasing property, was found to have the highest hardness. This result means that HPC formulated into the base forms the most rigid gel structure to resist the erosion of the ointment and to control the drug release. 相似文献
43.
44.
Izumi Sakamoto Kazuya Iwaoka Yuta Kawada Takanori Naito Kazuyoshi Makida Yuki Takeuchi Takeshi Nishii Mitsuyo Horikawa Hiroto Kaku Tetsuto Tsunoda 《Tetrahedron》2018,74(24):3052-3060
3,3-Dimethoxypropylsulfonyl (Dimps) chloride was prepared and used as a new versatile sulfonating agent for ammonia, primary and secondary amines to afford corresponding Dimps-amides in excellent yields. The resulting N-nonsubstituted and N-monosubstituted Dimps-amides, activated amines, were alkylated satisfactorily under new Mitsunobu conditions. The Dimps group was removed by treatment in aqueous solution under acidic followed by basic conditions. Furthermore, epilachnene, the defensive droplets from the Mexican bean beetle, Epilachna varivestis, was synthesized utilizing this Dimps methodology in short steps. 相似文献
45.
Hanaoka T Hayashi H Tago T Kishida M Wakabayashi K 《Journal of colloid and interface science》2001,235(2):235-240
We investigated the in situ immobilization of ultrafine particles synthesized in a water/oil (w/o) microemulsion to silica for its possible application to supported metal catalysts. ZnS particles immobilized to silica by the ME method were consistent with those synthesized in a w/o microemulsion. Therefore, ZnS particles in a w/o microemulsion could be immobilized to silica without aggregation by this method. The relationship between the method of synthesizing Rh ultrafine particles in a w/o microemulsion and the diameter and diameter distribution of Rh particles immobilized to silica was studied. Rh-SiO(2) catalysts with a sharp diameter distribution could be prepared by immobilizing Rh-hydrazine complex particles because these complex particles would be very stable in a w/o microemulsion. The Rh particle diameters of Rh-SiO(2) catalysts prepared by changing the amount of silica produced were almost identical. Accordingly, the Rh particle diameter of Rh-SiO(2) catalysts could be controlled independently of Rh content by the ME method. Copyright 2001 Academic Press. 相似文献
46.
Yanagi T Kikuchi K Takeuchi H Ishikawa T Nishimura T Yamamoto I 《Chemical & pharmaceutical bulletin》2001,49(8):1018-1023
The synthetic route for a uterine relaxant, bis(2-[[(2S)-2-([(2R)-2-hydroxy-2-[4-hydroxy-3-(2-hydroxyethyl)-phenyl]ethyl]amino)-1,2,3,4-tetrahydronaphthalen-7-yl]oxy]-N,N-dimethylacetamide) sulfate (KUR-1246), was established by the coupling of optically active components, the bromohydrin 14 and the amine 24. We now describe the practical synthesis of these two optically active components. Bromohydrin 14 was obtained by the asymmetric borane reduction of the prochiral phenacyl bromide 13 using a catalyst prepared from aluminum triethoxide and a chiral amino alcohol. The other optically active component 24 was prepared from (S)-AMT. 相似文献
47.
Steroid-selective polymers were prepared by the molecular imprinting technique, using 2-(methacryloyloxy)ethyl phosphate as functional monomer. The retentivity and selectivity of the obtained imprinted polymers were evaluated by liquid chromatography. The cholesterol-imprinted polymer showed higher affinity for cholesterol than that for cholesterol derivatives. The selectivity of the imprinted polymer was superior to the imprinted polymer prepared with the conventional functional monomer, 2-(trifluoromethyl)acrylic acid. Estradiol was also imprinted and gave similar results, demonstrating that 2-(methacryloyloxy)ethyl phosphate would be suitable for imprinted polymers of cholesterol and related compounds. 相似文献
48.
T. Takeuchi Y. Nakano A. Aoki S. Ohmori T. Tsukatani 《Journal of Radioanalytical and Nuclear Chemistry》1987,112(1):259-272
Human hair collected from the mercury, arsenic and cadmium polluted areas has been analysed by instrumental neutron activation method. The concentrations of 27 elements were compared with those of normal Japanese. Correlation coefficients of logarithmic concentrations between the elements were calculated and their significance levels were determined. Factor contribution and factor loadings of the elements were calculated for each factor by making use of principal component analysis. The factor score of each sample was also calculated for each factor to examine the effects of the contamination by heavy metals on individuals. 相似文献
49.
50.
Interaction of luminol with phosphomolybdic, phosphovanadomolybdic and silicomolybdic acids was studied by examination of chemiluminescence spectra, measurement of ESR spectra, investigation of reaction order, and elucidation of inhibition effects. A scheme of the reaction mechanism is proposed. 相似文献