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51.
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Baked-bean waste was found to be a favorable substrate for amylase production by Aspergillus foetidus NRRL 337. Under optimum conditions, the yields of α-amylase (EC 3.2.1.1) and glucoamylase (EC 3.2.1.3) were 47 and 226 U, respectively, per ml of the waste fermented. 相似文献
53.
The apparent penetration activity of Schistosoma mansoni cercariae was quantified by means of an in vitro assay with a radioactively labeled Type I collagen gel. Both live cercariae and cercarial preacetabular gland secretions degraded the collagen. The addition of skin lipid or linoleic acid to the gel surface enhanced the degradation by live cercariae. 相似文献
54.
Leucocytosis was shown to occur in the pulmonate gastropod Biomphalaria glabrata exposed to the trematode Echinostoma lindoense. In these sensitized snails, the leukocyte count in the hemolymph was elevated 3 to 5 days postexposure to miracidia, and prior to complete encapsulation of sporocysts. This increase continued 1 to 5 days after destruction of sensitizing, irradiated E. lindoense sporocysts. Counts returned to normal levels after this period. A significant and more rapid increase in numbers of circulating leukocytes occurred 1 to 6 hr after reexposure of snails to a sensitizing dose of nonirradiated E. lindoense sporocysts. The leukocyte counts usually returned to normal levels after this period, except in snails in which some resensitizing sporocysts remained alive. 相似文献
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Hyo Je Cho Kyungsun Kim Seo Yean Sohn Ha Yeon Cho Kyung Jin Kim Myung Hee Kim Dockyu Kim Eungbin Kim Beom Sik Kang 《The Journal of biological chemistry》2010,285(45):34643-34652
A meta-cleavage pathway for the aerobic degradation of aromatic hydrocarbons is catalyzed by extradiol dioxygenases via a two-step mechanism: catechol substrate binding and dioxygen incorporation. The binding of substrate triggers the release of water, thereby opening a coordination site for molecular oxygen. The crystal structures of AkbC, a type I extradiol dioxygenase, and the enzyme substrate (3-methylcatechol) complex revealed the substrate binding process of extradiol dioxygenase. AkbC is composed of an N-domain and an active C-domain, which contains iron coordinated by a 2-His-1-carboxylate facial triad motif. The C-domain includes a β-hairpin structure and a C-terminal tail. In substrate-bound AkbC, 3-methylcatechol interacts with the iron via a single hydroxyl group, which represents an intermediate stage in the substrate binding process. Structure-based mutagenesis revealed that the C-terminal tail and β-hairpin form part of the substrate binding pocket that is responsible for substrate specificity by blocking substrate entry. Once a substrate enters the active site, these structural elements also play a role in the correct positioning of the substrate. Based on the results presented here, a putative substrate binding mechanism is proposed. 相似文献
58.
Munkhtugs Davaatseren Jin-Taek Hwang Jae Ho Park Myung-Sunny Kim Shuaiyu Wang Mi Jeong Sung 《PloS one》2014,9(7)
Allyl isothiocyanate (AITC) is a phytochemical found in cruciferous vegetables that has known chemopreventive and chemotherapeutic activities. Thus far, the antiangiogenic activity of AITC has not been reported in in vivo studies. Herein, we investigated the effect of AITC on angiogenesis and inflammation in a mouse model of colitis. Experimental colitis was induced in mice by administering 3% dextran sulfate sodium via drinking water. To monitor the activity of AITC in this model, we measured body weight, disease activity indices, histopathological scores, microvascular density, myeloperoxidase activity, F4/80 staining, inducible nitric oxide synthase (iNOS) expression, cyclooxygenase-2 (COX-2) expression, and vascular endothelial growth factor (VEGF)-A/VEGF receptor 2 (VEGFR2) expression in the mice. We found that AITC-treated mice showed less weight loss, fewer clinical signs of colitis, and longer colons than vehicle-treated mice. AITC treatment also significantly lessened the disruption of colonic architecture that is normally associated with colitis and repressed the microvascularization response. Further, AITC treatment reduced both leukocyte recruitment and macrophage infiltration into the inflamed colon, and the mechanism these activities involved repressing iNOS and COX-2 expression. Finally, AITC attenuated the expression of VEGF-A and VEGFR2. Thus, AITC may have potential application in treating conditions marked by inflammatory-driven angiogenesis and mucosal inflammation. 相似文献
59.
Weihua Guo Jihee Jeong Zinsuh Kim Renqing Wang Enhye Kim Sunghwan Kim 《Biochemical Systematics and Ecology》2011,39(4-6):352-360
To study the genetic diversity and population structure of Lilium tsingtauense Gilg (Qingdao Lily), we collected 648 samples from 12 sites in China and Korea, and analyzed their Inter-Simple Sequence Repeat (ISSR) molecular markers and morphological characters. ISSR data revealed a relatively high genetic diversity at the species level, with 72.31% polymorphic loci, effective numbers of alleles of 1.437, average expected heterozygosity of 0.231 and Shannon’s information index of 0.369. Considerable genetic differentiation among the natural populations (GST = 0.144) and the gene flow (Nm = 1.487) were detected. AMOVA analysis and UPGMA-dendrogram suggested a hierarchical regional structure among populations, and spatial autocorrelation analysis showed a micro-scaled spatial structure. Furthermore, there was a high correlation between morphological characters and genetic parameters obtained from ISSR parameters. There was only a low genetic differentiation among the different morphological types of L. tsingtauence in China. Based on these findings, we recommend in situ and ex situ conservation strategies for the preservation of L. tsingtauense. 相似文献