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191.
Ji W. Chung Dongjin Shin June M. Kwak Joonil Seog 《Journal of molecular recognition : JMR》2013,26(6):268-275
The selective interactions between DNA and miniature (39 residues) engineered peptide were directly measured at the single‐molecule level by using atomic force microscopy. This peptide (p007) contains an α‐helical recognition site similar to leucine zipper GCN4 and specifically recognizes the ATGAC sequence in the DNA with nanomolar affinity. The average rupture force was 42.1 pN, which is similar to the unbinding forces of the digoxigenin–antidigoxigenin complex, one of the strongest interactions in biological systems. The single linear fit of the rupture forces versus the logarithm of pulling rates showed a single energy barrier with a transition state located at 0.74 nm from the bound state. The smaller koff compared with that of other similar systems was presumably due to the increased stability of the helical structure by putative folding residues in p007. This strong sequence‐specific DNA–peptide interaction has a potential to be utilized to prepare well‐defined mechanically stable DNA–protein hybrid nanostructures. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
192.
193.
Tatsuo Koyanagi Shin’ichi Hareyama Minoru Ota 《Bioscience, biotechnology, and biochemistry》2013,77(1):3-6
The effect of riboflavin on development of hypertension in rats given a high salt diet was studied. Large doses of riboflavin prevented both elevation of blood pressure and rise of cholesterol levels in the serum. The increase in liver monoamine oxidase activity of the rats fed riboflavin was confirmed. 相似文献
194.
Shin Sato Kin-ichi Nakamura Makoto Tadenuma 《Bioscience, biotechnology, and biochemistry》2013,77(3):308-313
Coloring reaction of sake caused by exposure to sun-light was investigated. There is one of the coloring reactions in which deferri-ferrichrysin participate. The reaction was named Reaction I.Deferri-ferrichrysin, tyrosine, Mn2+ and unknown nitrogenous compound named conveniently compound X were essential for Reaction I and citric acid was stimulative.Compound X was purified by using Amberlite IR 120 (H type) column, active carbon column, silicic acid column and alumina column, and crystallized from methanol-water (1 : 1).The crystals decomposed at 288~290°C. The ultraviolet and infrared spectra of the compound X were essentially identical with those of authentic kynurenic acid.From these results the compound X was identified as kynurenic acid.Since kynurenic acid alone did not cause the color development and riboflavin could be substituted for kynurenic acid in Reaction I, kynurenic acid may act as photosensitizer in Reaction I. 相似文献
195.
Masato Tamari Shin Hasegawa Masao Kametaka 《Bioscience, biotechnology, and biochemistry》2013,77(10):2117-2118
For Podospora anserina, several studies of cellulolytic enzymes have been established, but characteristics of amylolytic enzymes are not well understood. When P. anserina grew in starch as carbon source, it accumulated glucose, nigerose, and maltose in the culture supernatant. At the same time, the fungus secreted α-glucosidase (PAG). PAG was purified from the culture supernatant, and was found to convert soluble starch to nigerose and maltose. The recombinant enzyme with C-terminal His-tag (rPAG) was produced with Pichia pastoris. Most rPAG produced under standard conditions lost its affinity for nickel-chelating resin, but the affinity was improved by the use of a buffered medium (pH 8.0) supplemented with casamino acid and a reduction of the cultivation time. rPAG suffered limited proteolysis at the same site as the original PAG. A site-directed mutagenesis study indicated that proteolysis had no effect on enzyme characteristics. A kinetic study indicated that the PAG possessed significant transglycosylation activity. 相似文献
196.
Tamio Mizukami Morimasa Yagisawa Shin Kawahara Hiroshi Kase Tetsuo Oka Akira Furuya 《Bioscience, biotechnology, and biochemistry》2013,77(4):1015-1018
We previously constructed an l-threonine-producing strain of E. coli W, KY8280, which is an Ile+ revertant of KY8279 which requires l-methionine, a,£-diaminopimelic acid and l-isoleucine [H. Kase et al., Agric. Biol. Chem., 35, 2089 (1971)]. From KY8280, another l-threonine-hyperproducing strain, KY8366, was obtained as an α-amino-β-hydroxy valeric acid (AHV, a threonine analog)-resistant mutant. Enzymatic analysis revealed that KY8280 constitutively expressed 8-fold higher l-threonine-sensitive aspartokinase I activity than KY8279. In addition, KY8366 constitutively expressed 13-fold higher l-lysine-sensitive aspartokinase III activity than KY8280. Such elevated levels of aspartokinases may contribute to the hyperproduction of l-threonine by these mutant strains. KY8366 produced 28 mg/ml of l-threonine in a culture medium fed with 12% glucose. 相似文献
197.
Eiko Matsumura Eiko Yamamoto Atsushi Numata Tatsu Kawano Takashi Shin Sawao Murao 《Bioscience, biotechnology, and biochemistry》2013,77(5):1355-1357
Esters selected from the combination of tricycloalkanecarboxylic acids and some representative pyrethroidal alcohols were prepared, and their insecticidal activities were measured by topical application on housefly, mosquito and German cockroach. Both the exo- and endo-isomers of 2,3-trimethylenenorbornane-2-carboxylic acid exhibited a high level of activity when esterified with m-phenoxymandelonitrile. Piperonyl butoxide showed a strong synergistic effect on some of the esters. Several structural resemblances were found among these active tricyclic acids and the chrysanthemummonocarboxylic acids, which were suggested to be related to insecticidal activity. 相似文献
198.
Byeong Tak Jeon Rok Won Heo Hyun Joo Shin Chin-ok Yi Yu Hee Lee Han-nah Joung 《Bioscience, biotechnology, and biochemistry》2013,77(3):482-489
A Vigna nakashimae (VN) extract has been shown to have antidiabetic and anti-obesity effects. However, the mechanism underlying the effect of a VN extract on hepatic inflammation and endoplasmic reticulum (ER) stress remains unclear. In the present study, we investigated how a VN extract protects against the development of non-alcoholic fatty liver disease (NAFLD). A VN extract for 12 weeks reduced the body weight, serum metabolic parameters, cytokines, and hepatic steatosis in high-fat diet (HFD)-fed mice. A VN extract decreased HFD-induced hepatic acetyl CoA carboxylase and glucose transporter 4 expressions. In addition to the levels of high-mobility group box 1 and receptor for advanced glycation, the hepatic expression of ATF4 and caspase-3 was also reduced by a VN extract. Thus, these data indicate that a chronic VN extract prevented NAFLD through multiple mechanisms, including inflammation, ER stress, and apoptosis in the liver. 相似文献
199.
200.
The matrix metalloproteinases (MMPs) are well known to responsible for the degradation of extracellular matrix (ECM) during tissue remodelling such as wound healing, metamorphosis, and regeneration. In present study, gelatinase activities were investigated in normal and retinoic acid (RA)-treated limb regenerates. During the early phase of limb regeneration, gelatinase activities increased greatly, and RA caused the enhanced and prolonged gelatinase activities. We also isolated full length of Hynobius MMP-9, and its spatial and temporal expression profiles were examined in normal, RA-treated, and denervated limb regenerates. Whole mount in situ hybridization showed that the expression of MMP-9 increased in the wound epidermis at the wound healing stage and early phase of dedifferentiation stage. In addition, RA enhanced remarkably its expression both in terms of level and duration in the wound epidermis. However, expression signal of MMP-9 was barely detectable in denervated in limb regenerates. Our results may indicate that MMP-9 plays important role(s) in the dedifferentiation process by participating in ECM degradation and enhancement of MMP-9 expression and activity might be closely related to RA-evoked pattern duplication. 相似文献