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51.
Norihiro Azuma Shuichi Kaminogawa Kunio Yamauchi 《Bioscience, biotechnology, and biochemistry》2013,77(9):2655-2660
Human casein micelles were reconstituted from isolated κ- and β-caseins and calcium ions. Micelle formation was recognized in the presence of calcium chloride even at the low concentration of 5mM. At pH levels ranging from 5.5 to 8.0, the re-formed micelles were quite stable so that precipitation of β-casein was not observed. The large micelles were constituted by a higher ratio of β-casein to κ-casein (16:1 by weight) than the small micelles (3: 1). The κ-casein in the small micelles contained carbohydrates to about 43% (w/w) in the molecule, whereas that in the large micelles was only about 25%. When the casein micelles were re-formed from κ-easein and fractionated β-casein components, the extent of phosphorylation of the β-casein component was found to influence the micelle formation; i.e., the β-casein component with no phosphate (the 0-P form) was disadvantageous to form micelles, but the component with 5 phosphates (the 5-P form) formed micelles most easily. 相似文献
52.
Shuichi Kaminogawa Shunichi Dosako Kunio Yamauchi 《Bioscience, biotechnology, and biochemistry》2013,77(12):2337-2341
Some molecular properties of αs1-κ-casein complex, αs1- and κ-casein polymers were examined by gel filtration, ultracentrifugation, and viscometry at pH 7.1. The Stoke’s radii of αs1-κ-casein complex, αs1- and κ-casein polymers were 99, 44 and 108 Å, respectively. The molecular weight of the above proteins were approximately 45 × 104, 10 × 104 and 80 × 104, respectively. The stokes radius of αs1-κ casein complex reduced compared with that of κ-casein polymer and the molecular weight of the complex was about half that of κ-casein polymer. These results suggest that κ-casein polymer dissociates into 4 smaller particles when αs1-κ-casein complex is formed. The frictional coefficient and Scheraga-Mandelkern constants for each protein suggest that the molecular shape of αs1-casein polymer is globular and that of αs1-κ-casein complex and κ-casein polymer is rod-like. 相似文献
53.
Shuichi Kaminogawa Kunio Yamauchi 《Bioscience, biotechnology, and biochemistry》2013,77(12):2343-2348
A γ-casein-like fraction (FIV) was isolated from the β-casein A hydrolyzate by milk protease and compared with γ-casein. The mobility in polyacrylamide gel electrophoresis, sedimentation coefficient, molecular weight, amino acid composition and terminal amino acids of FIV were almost coincided with those of γ-casein. It is suggested that γ-casein is possibly a product of β-casein hydrolysis by milk protease. 相似文献
54.
Shuichi Ishida Mitsuo Ida Osamu Yamada 《Bioscience, biotechnology, and biochemistry》2013,77(4):410-421
Formation of a sulfonium-like intermediate was assumed in the hydrolysis of the 2-bromoethylthiobenzenes. A linear free energy relationship was found between the hydrolysis rate of a certain substituted 2-bromoethylthiobenzene and the molar fraction of water in the solvent. The effect of the substituent on the rate constant was attributed not only to the activation energy but also to the entropy change of activation. The negative ρ-value in the formation of the sulfonium-like intermediate in aqueous solution was comparable with that obtained in the ρ-σ-π analysis for ovicidal activity of the compounds.For the reaction of the substituted 2-bromoethylthiobenzenes with highly excess amount of 4-(p-nitrobenzyl)-pyridine, the ρ-value was found to be negative, which means that the formation of the sulfonium-like intermediate is a rate determining step. Whichever might be more important, the hydrolysis or alkylation, as to the ovicidal action of the compounds, the formation of the sulfonium-like intermediate, could be considered to be an essential step. 相似文献
55.
Osamu Yamada Shuichi Ishida Fumio Futatsuya Kensaku Ito Hiroshi Yamamoto Katsura Munakata 《Bioscience, biotechnology, and biochemistry》2013,77(6):1235-1240
The discovery that anisomycin showed plant growth-regulating activity led to the investigation of compounds having p-methoxyphenyl group; the p-anisole derivatives. 4-Methoxydiphenylmethanes and related compounds inhibited the growth of both shoots and roots in test plants. Growth-inhibitory activity in the series of 4-methoxydiphenylmethanes was lowered by an increase in the electron donating or withdrawing ability of the substituent and was parabolically dependent on the Hammett’s σ. Selective actions of these compounds in their growth inhibition are discussed based on correlations between their activities against barnyard grass and other test plants.Some 4-methoxydiphenylmethanes induced chlorosis, a disturbance in phototropism or geotropism, and root hypertrophy. 相似文献
56.
Norihiro Azuma Shuichi Kaminogawa Kunio Yamauchi 《Bioscience, biotechnology, and biochemistry》2013,77(8):2025-2031
The nutritional efficiency of quinolinic acid as a substitute for nicotinic acid was investigated using weanling rats Of the Sprague Dawley strain (3-weeks old) fed a nicotinic acid-free, tryptophan-limited diet containing various amounts of nicotinic acid or quinolinic acid. Judging from the growth response, food efficiency ratio, levels of NAD activity in the blood, liver, brain and upper small intestine, and urinary excretion of niacin we have concluded that exogenous quinolinic acid is approximately 1/9 as active as nicotinic acid. As many foods contain quinolinic acid, dietary quinolinic acid cannot be ignored from the standpoint of tryptophan and nicotinic acid replacement. 相似文献
57.
Shuichi Kaminogawa Shun-ichi Dosako Kunio Yamauchi Kazuhiko Kinoshita 《Bioscience, biotechnology, and biochemistry》2013,77(2):533-539
Conjugates of αs1-,κ-caseins and αs1-,κ-casein complex were prepared with dimethylaminonaphthalenesulfonate and pyrenebutyrate. Their fluorescence lifetimes and the rotational relaxation times were measured by single photon counting technique and fluorescence depolarization technique, respectively. Both dimethylaminonaphthalenesulfonate and pyrenebutyrate conjugates had more than two lifetimes and the longer lifetime of pyrenebutyrate conjugates was near 140 nsec.The rotational relaxation time of pyrenebutyrate αs1-,κ-casein complex was smaller than that of pyrenebutyrate κ-casein polymer, which suggested that the complex formation of αs1- and κ-casein polymers led to dissociation of the κ-casein polymer.Changes of the rotational relaxation time as a function of weight ratio of αs1- and κ-casein polymers (αs1/κ) showed the specific variation and it was suggested that 4 moles of αs1-κ-casein complex were formed from one mole of κ-casein polymer. 相似文献
58.
Maki Komiyama Hiromichi Wada Shuichi Ura Hajime Yamakage Noriko Satoh-Asahara Akira Shimatsu Hiroshi Koyama Koichi Kono Yuko Takahashi Koji Hasegawa 《PloS one》2013,8(8)
Cigarette smokers are generally known to gain weight after quitting smoking, and such weight gain is thought to contribute to the worsening of glucose tolerance. While smoking cessation therapy such as nicotine replacement is useful to minimize post-cessation weight gain, substantial gain occurs even during the therapy. The purpose of the present study was to identify factors associated with weight gain during smoking cessation therapy. We evaluated 186 patients(132 males and 54 females)who visited our outpatient clinic for smoking cessation, and successfully achieved smoking abstinence. We performed gender-adjusted regression analysis for the rate of BMI increase from the beginning of cessation to 3 months after initiation. Furthermore, we performed multivariate analysis to investigate factors that determine the BMI increase after smoking cessation. The mean BMI significantly (p<0.0001) increased from 23.5±3.6 kg/m2 at the initial consultation to 23.9±3.8 kg/m2 at 3 months after the start of therapy. There was no significant difference in the extent of BMI increase between nicotine patch and varenicline therapy groups. Factors significantly correlated with the %BMI increase at 3 months after the start of therapy were triglyceride (p = 0.0006, βa = 0.260), high-density lipoprotein cholesterol (p = 0.0386, βa = −0.168), daily cigarette consumption (p = 0.0385, βa = 0.154), and the Fagerström Test for Nicotine Dependence (FTND) score (p = 0.0060, βa = 0.203). Stepwise multivariate analysis demonstrated that triglyceride and the FTND score were the factors determining the post-cessation BMI increase and that the FTND score was the strongest one. The present study demonstrated that smokers with a high FTND score are more likely to gain weight during smoking cessation therapy. Thus, smokers with a high nicotine dependency may require intervention against weight gain in the cessation clinic. 相似文献
59.
We previously reported that CD44-positive cells were candidates for astrocyte precursor cells in the developing cerebellum, because cells expressing high levels of CD44 selected by fluorescence-activated cell sorting (FACS) gave rise only to astrocytes in vitro. However, whether CD44 is a specific cell marker for cerebellar astrocyte precursor cells in vivo is unknown. In this study, we used immunohistochemistry, in situ hybridization, and FACS to analyze the spatial and temporal expression of CD44 and characterize the CD44-positive cells in the mouse cerebellum during development. CD44 expression was observed not only in astrocyte precursor cells but also in neural stem cells and oligodendrocyte precursor cells (OPCs) at early postnatal stages. CD44 expression in OPCs was shut off during oligodendrocyte differentiation. Interestingly, during development, CD44 expression was limited specifically to Bergmann glia and fibrous astrocytes among three types of astrocytes in cerebellum, and expression in astrocytes was shut off during postnatal development. CD44 expression was also detected in developing Purkinje and granule neurons but was limited to granule neurons in the adult cerebellum. Thus, at early developmental stages of the cerebellum, CD44 was widely expressed in several types of precursor cells, and over the course of development, the expression of CD44 became restricted to granule neurons in the adult. 相似文献
60.