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211.
By immobilizing fungi on a urethane foam carrier (UFC), a novel solid-state fermentation system was developed in order to produce repeatedly industrial useful enzymes. In this study, alkaline protease was produced by growing Aspergillus oryzae 460 (ATCC 20386) in a flask scale. Repeated batch production of alkaline protease was carried out by exchanging a part of the culture broth with fresh medium every 12 hr. The effects of feeding medium composition, and feeding volume were examined. Alkaline protease production stopped in the early phase at high values of soluble starch feeding rate and culture broth dilution rate. The enzyme production continued longer when 10 to 30 g/l polypepton was added to the feeding medium. Using soluble starch solution as feeding medium, a maximum activity of 520,000 U/l-bulk volume alkaline protease was obtained at culture time of 168 hr where the culture conditions of soluble starch concentration and feeding volume were 100 g/l and 0.025 l/l-bulk volume/dose, respectively. Production of the enzyme continued for 300 hr and total aklaline protease activity reached 870,000 U/l-bulk volume by adding 30 g/l polypepton to the fresh medium. 相似文献
212.
Shigemichi Iha Kunzo Orita Tomoko Kannoh Toshihiko Utsumi Eisuke F. Sato Masayasu Inoue Kozo Utsumi 《Free radical research》1996,25(6):489-498
Effect of nitric oxide (NO) on the respiratory burst of neutrophils was examined under different oxygen tensions. Phorbol myristate acetate (PMA) stimulated oxygen consumption and superoxide (O2-) generation in neutrophils by a mechanism which was inhibited reversibly by NO. The inhibitory effect of NO increased significantly with a decrease in oxygen tension in the medium. The inhibitory effect of NO was suppressed in medium containing oxyhemoglobin (HbO2), a NO scavenging agent. In contrast, 3-morpholinosydnonimine (SIN-1), a compound that rapidly generates peroxynitrite (ONOO-) from the released NO and O2-, slightly stimulated the PMA-induced respiratory burst. These results suggested that NO, but not ONOO, might reversibly inhibit superoxide generation by neutrophils especially at physiologically low oxygen tensions thereby decreasing oxygen toxicity particularly in and around hypoxic tissues. 相似文献
213.
Nobuhiro Kanno Minoru Sato Eizou Nagahisa Yoshikazu Sato 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》1996,114(4):409-416
This is the first report of the purification of tauropine dehydrogenase (NAD: tauropine oxidoreductase) from a polychaete worm. In the sandwormArabella iricolor Montagu (Polychaet: Errantia), two forms of TaDH were detected: major component (pl = 7.5) and minor one (pI = 6.4). The major TaDH component was purified to homogeneity by means of (NH4)2SO4 precipitation, anion-exchange, affinity, chromatofocusing and hydrophobic chromatography, and characterized. From the molecular mass of 43.7 kDa obtained by rapid gel-filtration and that of 43.5 kDa by SDS-PAGE, the sandworm enzyme appeared to be a monomeric protein. Maximum rates of reduction of pyruvate and oxidation of tauropine were observed at pH 7.0 and 8.5, respectively. Pyruvate and taurine were preferred substrate for the enzyme. Apparent Km values determined using constant co-substrate concentrations were: 35.7 mM, 0.34 mM, and 0.036 mM for taurine, pyruvate and NADH, respectively, in the tauropine synthesizing reaction; and 4.8 mM and 0.051 mM for tauropine and NAD+, respectively, in the tauropine oxidizing reaction. The tauropine synthesizing reaction was subject to substrate inhibition by pyruvate: maximum rate was observed at 2.5–3.0 mM (inhibitory range of pyruvate concentration producing half-maximal rate was 26.8 mM). 相似文献
214.
Specimens of basidiomes and/or rhizomorphs ofArmillaria mellea complex and basidiomes ofRhodophyllus abortivus, developing on the same decaying stumps or stems of forest trees, were collected in three forests in Hokkaido. Normal basidiomes
ofR. abortivus were found near to, but free from, the rhizomorphs and/or basidiomes ofArmillaria, while abnormal basidiomes, as carpophoroid forms, were developed on the rhizomorphs ofArmillaria. Of three mycoparasiticArmillaria isolates found withR. abortivus, one was identified asA. gallica and two asA. jezoensis. The isolates ofR. abortivus showed excellent mycelial growth and rhizomorph formation on PDA. However, on MDA, RMDA and BMDA, they showed poor aerial
mycelia growth and no rhizomorphs. In the contrapositional cultures, the growth ofA. gallica was completely inhibited byR. abortivus on PDA but only slightly inhibited on MDA and RMDA. On the other hand, mutual inhibition at a distance was observed on BMDA.
The mycelial growth and rhizomorph formation inA. jezoensis were severely inhibited by the colony ofR. abortivus on PDA, but only slightly inhibited on MDA. On RMDA and BMDA, the colonies of twoArmillaria species andR. abortivus showed mutual inhibition at a distance and apparent rhizomorph formation by bothArmillaria species. 相似文献
215.
Isolation of the measles virus hemagglutinin protein in a soluble form by protease digestion. 总被引:4,自引:3,他引:1 下载免费PDF全文
The hemagglutinin (H) glycoprotein was isolated in a soluble form by digesting measles virus particles with an endoproteinase, Asp-N (from a Pseudomonas fragi mutant). Digestion of H with Asp-N brought about glycopeptides in three different forms, depending on the cleaving site: AHD, which has an M(r) of 66,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and which formed a disulfide-linked homodimer with an M(r) of 132,000, and two monomeric digestion products, AHM-1 (with an M(r) of 64,000) and AHM-2 (with an M(r) of 58,000). The susceptibility of the H glycoprotein to the protease depended on the enzyme concentration. AHD was readily formed at a low concentration of Asp-N, while AHM-1 and AHM-2 required higher and even higher protease concentrations, respectively. All of the cleavage products reacted with monoclonal antibodies to various epitopes of the H protein; however, only AHD showed a significant hemagglutinin activity on African green monkey erythrocytes. The hemagglutinin activities of AHM-1 and AHM-2 were restored after a monoclonal antibody lacking the hemagglutination-inhibiting activity was added to the reaction mixture. AHDs purified by size-exclusion high-pressure liquid chromatography had two associating forms; one had an M(r) higher than and the other an M(r) as high as that of a tetramer. The former was associated noncovalently in addition to having two intermolecular disulfide bonds, and the latter was associated covalently with a single intermolecular disulfide bond and was also duplicated through a noncovalent association. In addition, both AHM-1 and AHM-2, having no intermolecular disulfide bond, were in a dimer form. These results suggest that AHM-1 and AHM-2 are monovalent in the hemagglutinin activity, while AHDs are divalent. Comparative analyses of the N termini of these soluble glycopeptides with the sequence of H suggested that the cysteine residue at position 139 was responsible for the intermolecular disulfide bonding between the monomeric H glycoproteins. The cysteine at position 154 was also suggested to participate in the forming of the intermolecular disulfide bond. 相似文献
216.
217.
Kunio Koshimura Yasutaka Takagi Soichi Miwa †Tsuneo Kido ‡Yasuyoshi Watanabe Yoshio Murakami Yuzuru Kato Tomoh Masaki 《Journal of neurochemistry》1995,65(2):827-830
Abstract: 6R-l -erythro-Tetrahydrobiopterin (6R-BH4) is a cofactor for aromatic l -amino acid hydroxylases and nitric oxide synthase. Recently, we have reported that independently of its cofactor activities, 6R-BH4 acts from the outside of neurons in the brain to enhance the release of monoamine neurotransmitters such as dopamine. To characterize the pharmacological properties of the action, we examined the effects of 6S-BH4, a diastereoisomer of 6R-BH4, on dopamine release in the rat striatum by using brain microdialysis and compared its effects with those of 6R-BH4. Perfusion of 6S-BH4 or 6R-BH4 through the dialysis probe increased extracellular dopamine levels (an index of in vivo dopamine release) concentration dependently; the maximal increase by 6S-BH4, was one-sixth of that by 6R-BH4. 6S-BH4 increased extracellular DOPA levels in the presence of NSD 1015, an inhibitor of aromatic l -amino acid decarboxylase (an index of in vivo tyrosine hydroxylase activity), to an extent similar to the increase induced by 6R-BH4. The increase in the DOPA levels induced by either of the pteridines was abolished after pretreatment of rats with α-methyl-p-tyrosine (an inhibitor of tyrosine hydroxylase). Under the same conditions, the 6S-BH4-induced dopamine release was abolished, but most of the 6R-BH4-induced increase persisted. Coadministration of 6S-BH4 with 6R-BH4 inhibited the increase in dopamine release induced by 6R-BH4 alone. These results show that 6R-BH4 stimulates dopamine release by acting at the specific recognition site on the neuronal membrane, and that 6S-BH4 acts as an antagonist of 6R-BH4 at this site, although it has cofactor activities. 相似文献
218.
The localization of the antigen for monoclonal antibody 9F11-B-E4 was clarified by immuno-electron microscopy. The antigens were localized on the mitochondria and Golgi bodies in the male germ cells and on the secretory granules of various glands cells in the penis bulb and subepidermal parenchymal tissue of Phagocata vivida. The results of the interspecific cross-reaction tests with seven other freshwater triclads showed that these secretory granules are species-specific. A positive interspecific reaction was showed with Dugesia (family Dugesiidae), but not with Polycelis within the same family Planariidae which suggests the position of Phagocata within the Planariidae needs to be reassesed. 相似文献
219.
Niji Ohta Naoki Sato Kunihiko Ueda Tsuneyoshi Kuroiwa 《Journal of plant research》1997,110(2):235-245
Cyanidioschyzon merolae andCyanidium caldarium are representative species among of the most primitive algae, although the two species are distinctly different in various
morphological traits. We determined the nucleotide sequence of therbcL gene and a flanking 8-kb region in the plastid genome of each of these algae. In both algae, 12 genes were identified in
this region, in an identical order. This gene order is not conserved in the plastid genomes of other species of the kingdom
Plantae that have been sequenced to data. An additional unidentified open reading frame was also found in the two algae that
we analyzed, which has not been described in any other species of algae includingPorphyra purpurea. Comparison of the amino acid sequences of selected genes also supported the conclusion thatCyanidioschyzon merolae andCyanidium caldarium are closely related and that they are distinct from other rhodophytes.
The nucleotide sequence data reported in this paper will appear in the DDBJ, EMBL and GenBank Nucleotide Sequence Databases
under the accession numbers D63675 and D63676. 相似文献
220.
Quintilio W. Sato R.A. da Silveira A.M. Barratt G. Fattal E. Bueno-da-Costa M.H. 《Biotechnology Techniques》1997,11(9):697-700
The advantages of the intrinsic fluorescence of the tryptophan and the absorbance of the methionine residues of the 18 kDa-hsp - a recombinant protein from Mycobacterium leprae - was exploited here to develop a sensitive and low costs method for protein assaying. They presented linearity between 3 and 1000 g of protein. The correlations between intrinsic fluorescence or absorbance at 230 nm and protein contents were both superiors to 0.99. These methods can be extended to others proteins with low aromatic residue contents. 相似文献