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51.
52.
Takeshi Kato Kimi Iwase Toshiharu Nagatsu Masami Hino Tadashi Takemoto Shumpei Sakakibara 《Molecular and cellular biochemistry》1979,24(1):9-13
Summary A new assay procedure for X-prolyl dipeptidyl-aminopeptidase activity in human serum was developed with glycylproline p-phenylazoanilide tosylate as substrate. p-Phenylazoaniline liberated by the enzyme reaction was measured photometrically at 493 nm after stopping the reaction with acid. This assay was simple and sensitive, and less than 50 l of human serum was required for the assay. Km value was 2.5 mm and the optimum pH was 8.7. After disc gel electrophoresis of human serum, the enzyme activity could be distinctly observed as a reddish band on the gel when the gel was incubated with this substrate. 相似文献
53.
Plant growth-promoting activities of alkoxycarbonylisoureas in relation to their chemical structures
Masami Ogawa Kozo Oyamada Takashi Matsui Junzo Tobitsuka Yoshio Yamazaki 《Phytochemistry》1976,15(12):1829-1835
A number of alkoxycarbonylisourea derivatives were synthesized and their plant growth-promoting activities examined by the rice (Oryza sativa) seedling test. Isourea compounds with an appropriate substituent such as a halogen atom or a methyl, ethyl or methoxy group at the para-position on a benzene ring in 1-alkoxycarbonyl-2-alkyl-3-phenylcarbamoylisoureas promoted the growth of rice seedlings and acted as a highly active gibberellic acid-synergist when used in combination with gibberellic acid. The common structural requirements of isourea derivatives applied well for a growth promoter and a gibberellic acid-synergist. 相似文献
54.
Exposure of Avena coleoptile sections to 8% O2 brought aboutrespiration decrease, resulting in a decrease of ATP production.The pH at the cell wall surface slightly rose in sections exposedto 8% O2, while their growth was greatly accelerated. Moreover,this growth acceleration was observed even in sections treatedwith CCCP known to make membranes permeable for protons. Weconcluded that the growth acceleration with reduction of O2concentration is probably not the result of secretion of H+ions into cell wall compartments. Results of this study provided evidence to support the hypothesisthat there is an inverse relationship between hydroxyproline-proteinlevel and the ability of a cell to undergo rapid cell elongation.Total labeling of the cell wall fraction with 14C-proline wasunaffected by 8% O2 treatment, although the radioactivitiesof hydroxyproline incorporated into this fraction during thetreatments fell to about 45% of the control. Moreover, the radioactivitiesof hydroxyproline incorporated into the SLS-insoluble cell wallfraction of sections exposed to 8% O2 decreased to about 30%of the control. This decrease of hydroxyproline was also observedin sections treated with cycloheximide, which inhibits the secretionof H+ ions into the cell wall compartment. Reduction of O2 concentrationin the surrounding atmosphere affects not only the hydroxylationof peptidyl proline, but also the binding of hydroxyproline-protein(s)to cell wall polysaccharides, and the resulting decrease ofthe protein rigidly bound to them may induce cell elongation. (Received December 5, 1975; ) 相似文献
55.
1. Addition of KCN to aerobic, rotenone-inhibited rat liver mitochondria with out addition of substrate caused reduction of cytochromes b-562 (having an alpha-band at 562 nm at room temperature), c + c1, and a + a3. The effect of KCN on cytochrome b-562 was reversed by pentachlorophenol, though the effect of KCN on cytochromes c+c1 and a+a3 was not reversed by this uncoupler.2. Addition of ATP to aerobic, rat liver mitochondria inhibited with 500 muM KCN under conditions were cytochromes b-562, c+c1 and a+a3 were reduced, caused reduction of cytochrome b-566. The absorbance spectrum of cytochrome b-566 had an alpha-band at 565.5 nm, a beta-band at 538 nm and a gamma-band at 431 nm, but no shoulder around 558 nm at room temperature. 3. Addition of succinate to rotenone-KCN-inhibited and ATP-treated rat liver mitochondria under conditions where cytochromes b-566, b-562, c+c1 and a+a3 were already fully reduced, caused reduction of cytochrome b-558 (having an alpha-band at 558 nm, a beta-band at 527 nm and a gamma-band at 426 nm at room temperature) after exhaustion of molecular oxygen in the reaction medium, without any contribution from a long-wavelength species (cytochrome b-566). 4. It was concluded that the 558-nm band is not a short-wavelength shoulder of cytochrome b-566, but is due to a different species from cytochrome b-566. 相似文献
56.
The entropy of the amino acid sequences coded by DNA is considered as a measure of diversity or variety of proteins, and is taken as a measure of evolution. The DNA or m-RNA sequence is corsidered as a stationary second-order Markov chain composed of four kinds of bases. Because of the biased nature of the genetic code table, increase of entropy of amino acid sequences is possible with biased nucleotide sequence. Thus the biased DNA base composition and the extreme rarity of the base doubletC
p
G of higher organisms are explained. It is expected that the amino acid composition was highly biased at the days of the origin of the genetic code table, and the more frequent amino acids have tended to get rarer, and the rarer ones more frequent. This tendency is observed in the evolution of hemoglobin, cytochrome C, fibrinopeptide, immunoglobulin and lysozyme, and protein as a whole. 相似文献
57.
Abstract The kinetics of budding/dividing of parent cells at different culture ages, spread on a fresh medium, was formulated by the following model N t = N ∞ [1 − exp (− λ ( t − t r) ] where N t is the number of budding/dividing cells in the parent population at time t , N ∞ is the expected number of budding/dividing cells at infinite time, λ is the rate of budding/dividing of parent cells, and t r is the retardation time. The rate of budding/dividing λ decreased with the increase in the culture age of the parent cell population. 相似文献
58.
To understand how baidzharakhs (relic mounds enclosing polygonal ice blocks in permafrost) affect the zonal distribution of
vegetation, vegetation was measured in 145 plots of area 50 cm × 50 cm on a coastal terrace facing the Arctic Ocean in northern
Siberia. Cluster analysis classified five community types that were zonally distributed along the coastline. α-diversities
(species richness and diversity) were not different among vegetation types except for vegetation close to the coastline. On
and around baidzharakhs, burrows created by lemmings were frequently observed, and plant cover was low, suggesting that baidzharakhs
support habitats for rodents. Disturbances by rodent habits caused plant cover to decline but did not change α-diversity.
Two vegetation types that developed only on baidzharakhs were found at intermediate distances between the seacoast and inland
areas. Because these two vegetation types are azonally distributed, β- and γ-diversities were increased by permafrost-derived
topography, i.e., baidzharakh, and/or disturbance by rodents of which suitable nesting habitat is provided by baidzharakh. 相似文献
59.
Moeka Fujita Miyuki Kusajima Yasuko Okumura Masami Nakajima Kiwamu Minamisawa 《Bioscience, biotechnology, and biochemistry》2017,81(8):1657-1662
A plant growth-promoting bacteria, Azospirillum sp. B510, isolated from rice, can enhance growth and yield and induce disease resistance against various types of diseases in rice. Because little is known about the interaction between other plant species and this strain, we have investigated the effect of its colonization on disease resistance in tomato plants. Treatment with this strain by soil-drenching method established endophytic colonization in root tissues in tomato plant. The endophytic colonization with this strain-induced disease resistance in tomato plant against bacterial leaf spot caused by Pseudomonas syringae pv. tomato and gray mold caused by Botrytis cinerea. In Azospirillum-treated plants, neither the accumulation of SA nor the expression of defense-related genes was observed. These indicate that endophytic colonization with Azospirillum sp. B510 is able to activate the innate immune system also in tomato, which does not seem to be systemic acquired resistance. 相似文献