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91.
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93.
Pituitary adenylate cyclase-activating peptide (PACAP) is widely distributed throughout the nervous system. PACAP not only acts as a neurotransmitter but also elicits a broad spectrum of biological action via the PACAP-specific receptor, PAC1. However, no studies have investigated PACAP and PAC1 in the periodontal ligament (PDL), so we aimed to perform this investigation in rats after tooth luxation. In the PDL of an intact first molar, there are few osteoclasts and osteoblasts. However, at days 3 and 5 after luxation, large PAC1-positive cells, thought to be osteoclasts because of their expression of the osteoclast marker, tartrate-resistant acid phosphatase, were detected in appreciable numbers. Osteoblast numbers increased dramatically on day 7 after luxation, and PAC1-positive mononuclear small cells were increased at day 14, many of which expressed the osteoblast marker, alkaline phosphatase. PACAP-positive nerve fibers were rarely detected in the PDL of intact first molars, but were increasingly evident at this site on days 5 and 7 after luxation. Double-immunofluorescence analysis demonstrated the relationship between PACAP-positive nerve fibers and PAC1-positive osteoclasts/-blasts in the PDL. At 5 days after luxation, PACAP-positive nerve fibers appeared in close proximity to PAC1-positive osteoclasts. At 7 days after luxation, PACAP-positive nerve fibers appeared in close proximity to PAC1-positive osteoblasts. These results suggest that PACAP may have effects on osteoclasts and osteoblasts in the PDL after tooth luxation and thus regulate bone remodeling after these types of injury.  相似文献   
94.
The Aspergillus oryzae glucoamylase-encoding gene glaB is expressed specifically and strongly only during solid-state cultivation (SSC). To elucidate the basis for the specificity, the glaB promoter was analyzed by electrophoretic gel mobility shift assay (EMSA) which indicated two protein-binding elements from ?382 to ?353 and from ?332 to ?313. To confirm that these regions contained cis-elements, deletion analysis of the promoter was undertaken using β-glucuronidase as a reporter. The results of the deletion analysis were consistent with the EMSA results. The promoter missing the ?332 to ?313 element was not induced by low water activity stress during SSC.  相似文献   
95.
2-Nitropropane dioxygenase, purified to homogeneity by an improved method from a yeast, Hansenula mrakii, has a molecular weight of 42,000, and consists of a single polypeptide. The enzyme contains 1 mol of FAD per mol of enzyme. The iron protein associated with previous preparations was removed by the present purification procedures. The enzyme catalyzes the oxygenative denitrification of anionic nitroalkanes much more effectively than that of the neutral ones with the optimum pH of 6.5. The Michaelis constants for the anionic substrates are as follows: 2-nitropropane, 1.61 mM; 1-nitropropane, 3.23 mM; nitroethane, 3.13 mM, and 3-nitro-2-butanol, 0.59 mM.  相似文献   
96.
Some benzophenones substituted with methyl, methoxy, hydroxy or halogen groups inhibited growth and induced chlorosis in various plants. The structure activity relationships about the chlorosis-inducing activity and the growth inhibitory activity of the 3-methyl-benzophenones were well expressed by use of hydrophobic contant π, and Hammett’s σ. The highest selectivity for phytotoxic activities against barnyardgrass and the rice plant was with 3,3′-dimethyl-4-methoxybenzophenone (Methoxyphenone).  相似文献   
97.
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   
98.
Pyrroloquinoline quinone-dependent quinoprotein alcohol dehydrogenases (PQQ-ADH) require ammonia or primary amines as activators in in vitro assays with artificial electron acceptors. We found that PQQ-ADH from Pseudomonas putida KT2440 (PpADH) was activated by various primary amines, di-methylamine, and tri-methylamine. The alcohol oxidation activity of PpADH was strongly enhanced and the affinity for substrates was also improved by pentylamine as an activator.  相似文献   
99.
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   
100.
The biosynthetic pathway of vitamin B6 (abbreviated as Be) has been studied with the cell-suspension of B6-producing bacteria, Achromobacter cycloclastes A.M.S. 6201. The distribution of 14C in the Be molecule prepared with the cell-suspensions containing glycerol-1,3-14C, glycerol-2-14C or γ-aminobutyric acid-U-14C was investigated by using three novel degradation methods. The results showed that carbon skeletons of glycerol and γ-aminobutyric acid were used for the formation of the major part of B6 carbon skeleton respectively. The implication of these compounds as precursors of B6 was discussed.  相似文献   
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