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141.
Yoshimitsu Ueno Kohsuke Hori Ryo Yamauchi Makoto Kiso Akira Hasegawa Koji Kato 《Carbohydrate research》1981,96(1):65-72
Laminarabiose, cellobiose, and gentiobiose were acetonated with 2,2-dimethoxy-propane under various conditions. Two isopropylidene acetals in which the reducing D-glucose residue had the furanoid form were obtained from laminarabiose, and two, in which the reducing D-glucose residue formed the acyclic dimethyl acetal, from cellobiose. Gentiobiose gave both types of isopropylidene compound. 相似文献
142.
Absence of pantothenic acid in gramicidin S synthetase 2 obtained from some mutants of Bacillus brevis 总被引:2,自引:0,他引:2
The pantothenic acid content of gramicidin S synthetase 2(GS 2) was estimated microbiologically with enzymes obtained from the wild strain and gramicidin S-lacking mutant strains of Bacillus brevis. Four mutant enzymes from BI-4, C-3, E-1, and E-2 lacked pantothenic acid. Other mutant enzymes from BII-3, BI-3, BI-9, and BI-2 contained the same amount of pantothenic acid as the wild-type enzyme. Pantothenic acid-lacking GS 2 belonged to group V of mutant enzymes, which could activate all amino acids related to gramicidin S; their complementary enzyme, gramicidin S synthetase 1(GS 1), lacked racemizing activity. To ascertain whether 4'-phosphopantetheine is involved in the formation of D-phenylalanyl-L-prolyl diketopiperazine (DKP) and gramicidin S, combinations were tested of intact GS 1 from the wild strain with various mutant GS 2 either containing or lacking pantothenic acid. Only the combinations of wild-type GS 1 with mutant GS 2 containing pantothenic acid could synthesize DKP. Combinations with pantothenic acid-lacking GS 2 also failed to elongate peptide chains. Pantothenic acid-lacking GS 2 could bind the four amino acids which constitute gramicidin S as acyladenylates and thioesters, but the binding abilities were lower than those of the wild-type enzyme and other mutant enzymes containing the pantothenic group. 相似文献
143.
Summary When horseshoe crab embryos were treated with NaHCO3 at the developmental stage when the germ disc appears, multiple embryos were formed. NaHCO3 may effect the formation of multiple embryos by binding Ca2+ ions of the embryo since multiple embryos were also formed by treatment with Ca2+ free sea water.The treatment caused the blastoderm layer to tear. When the embryos were returned to normal sea water after the treatment, the blastoderm recovered. Some cell masses, probably derived from the germ disc or its prospective cells, formed during the process of the recovery. Each cell mass developed into an embryo.Contributions from the Shimoda Marine Research Center, Nor. 348 相似文献
144.
Summary Detailed histochemical studies have been conducted on the distribution of various enzymes such as thiamine pyrophosphatase,
α-glucan phosphorylase, hexokinase, glucose-6-phosphate dehydrogenase, aldolase, lactate dehydrogenase and succinate dehydrogenase
in various components of the nucleusEdinger-Westphali, nucleus n. oculomotorii, nucleus ruber and nucleus niger of healthy adult male Wistar strain rats.
The thiamine pyrophosphatase reaction showed the morphological patterns of the Golgi apparatus characteristic for each nucleus.
The Golgi apparatus was well developed in the nucleusEdinger-Westphali, composing a network of highly fenestrated plates in the nucleus n. oculomotorii and nucleus ruber, and a simple network
in the nucleus niger. These results indicate that the former three nuclei need a rich energy supply and argue against the
possibility that the four nuclei have a secretory role.
The neurons of the nucleusEdinger-Westphali may derive their energy mainly from glucose of the circulating blood, but glial cells may serve as energy donators to the
neurons in the pars compacta of the nucleus niger, and the neurons of the other nuclei may derive energy from both sources.
These conclusions are consistent with the morphological patterns of the Golgi apparatus.
It is suggested that the neurons of the nucleusEdinger-Westphali, nucleus n. oculomotorii, nucleus ruber and of the pars lateralis of the nucleus niger may be equipped almost equally with
the Embden-Meyerhof pathway and with the hexose monophosphate shunt. But, the hexose monophosphate shunt is dominant in the
pars compacta of the nucleus niger. It is also suggested that the pattern of distribution of succinate dehydrogenase may parallel
that of lactate dehydrogenase. The nucleus n. oculomotorii, and nucleus ruber have a higher level of oxidative metabolism
than the nucleusEdinger-Westphali and the nucleus niger. The nucleusEdinger-Westphali may be representative of autonomic nuclei with low oxidative metabolism whereas the nucleus n. oculomotorii may represent
motor nuclei with high oxidative metabolism. Predominance of hexose monophosphate shunt, intense hexokinase reaction around
the neurons, and weak activity of succinate dehydrogenase indicate that the pars compacta of the nucleus niger belongs to
the category of “exceptional nuclei”. 相似文献
145.
It was reported previously that two spherical flacherie viruses of silkworm, FVS I and FVS II, had been isolated from flacherie silkworm larvae and the nucleic acid of FVS II was RNA as suggested by the experiments of incorporation of [3H]-uracil. In this paper, it has been confirmed by biochemical methods that the nucleic acid of FVS I and FVS II is RNA. FVS I and FVS II were labeled with 32P in flacherie silkworms, and the viruses were analyzed by sucrose density gradient centrifugation. When the 32P-labeled compound in the viruses was treated with 0.5 n KOH, the acid-insoluble 32P-labeled compound changed to acid-soluble compounds. It was determined by paper chromatography and ion-exchange column chromatography that the alkali-decomposed compounds included four ribonucleotides. Therefore, the viral nucleic acid of FVS I and FVS II was determined to be RNA. The correlations between FVS I and FVS II particles were discussed, and it was suggested that FVS I and FVS II might be closely related or were the same viral species. 相似文献
146.
K. Hori 《Journal of insect physiology》1975,21(6):1271-1274
Pectinase was detected in the salivary gland of the larvae of Lygus disponsi. The pectinase activity per bug may increase gradually from the first instar larva to the adult. The salivary gland of the third instar larva contained substances indirectly promoting plant growth, i.e. the factor promoting the activity of 3-indoleacetic acid (IAA) or the factor inhibiting the activity of IAA-oxidase, whereas those of the fourth and 5th instar larvae seemed to contain, in addition, auxins which directly promote plant growth. Larvae of all instars had a significant promoting factor only in fraction III of the salivary gland solution. The larvae are as toxic as the adults to sugar beet plants. The presence of pectinase and plant growth-promoting factors in the salivary gland is compared among mirid bugs, and their significance is discussed. 相似文献
147.
148.
The manganese content of the egg and embryo of the Medaka, Oryzias latipes was determined by activation analysis. A remarkable increase in the amount of manganese in the egg was observed within one hour after fertilization. The rate of increase was reduced by the gastrula stage and the concentration of manganese remained unchanged at a later stage. The accumulation of manganese by the Oryzias egg was discussed in relation to the effect of manganese on respiratory enzyme systems. 相似文献
149.
Catalysis by human leukocyte elastase: mechanistic insights into specificity requirements 总被引:1,自引:0,他引:1
Steady-state kinetic parameters were determined for the human leukocyte elastase catalyzed hydrolysis of a series of peptide-based thiobenzyl esters and p-nitroanilides. The peptide units are MeOSuc-Val, MeOSuc-Alan-Pro-Val (n = 0-2), and MeOSuc-Alan-Pro-Ala (n = 1 or 2). The results of this study suggest five important mechanistic features for HLE. Few important remote subsite contacts are established in the Michaelis complex. Full recognition and tight binding of the substrate occurs in the transition state for acylation. The P3-S3 interaction is critical during acylation. Subsite contacts are unimportant in deacylation. P1 specificity is regulated by peptide length. An important steady-state kinetic consequence of this specificity is that the rate-limiting step of kc for p-nitroanilide hydrolysis changes from acylation to deacylation as the peptide chain is lengthened. 相似文献
150.
Yoshimichi Hori 《Journal of plant research》1989,102(1):1-8
The adaptive significance of the emergence mode ofDioscorea japonica was studied with respect to initial plant size (seed, bulbil and tuber) and light intensity, using mathematical simulation
based on Yokoi's (1976) model.
Under 1.5% full sunlight conditions, plants emerging with only one leaf did not develop a shoot system throughout the growing
period (Hori and Oshima, 1986). Simulation indicated that, for this species of plant under poor productive conditions, the
optimal time for switch-over from the vegetative to reproductive growth phase to maximize the tuber weight at the end of the
growing period, occurred immediately following the start of autotrophic growth. By means of shoot growth patterns, small and
large size plants acquired the ability of shade tolerance and shade avoidance, respectively.
Further, the life history ofD. japonica could be expressed as a flow chart based on plant size and light intensity data. 相似文献