排序方式: 共有67条查询结果,搜索用时 15 毫秒
21.
Heinonen-Tanski H Kiuru T Ruuskanen J Korhonen K Koivunen J Ruokojärvi A 《Bioresource technology》2005,96(2):247-252
Thermophilic aeration of cattle slurry and food industrial by-products was studied with the aim to improve hygienic qualities of the slurry so that it could be used as a safe fertiliser for berries to be eaten raw. We also wanted to study if the process would be energetically favourable in an arctic climate. Cattle slurry alone or with whey and/or jam waste was treated. The tests were done in a well heat-insulated reactor with a 10 m(3) volume. Temperature increases up to over 70 degrees C could be recorded in 19 days even though some processes were carried out in winter time when the ambient air temperature was less than 0 degrees C. The heat energy formed was higher than the electrical energy needed to carry out the aeration. The hygienic qualities of the aerated product were good with only minor nitrogen losses. The end product could be useful as a fertiliser and soil improving compound to increase the organic matter content of agricultural soil. Cattle slurry alone was well suited as the raw material if attaining a high temperature was the main goal. A part of slurry could be replaced with food-industrial side products. Whey waste suited better for co-composting than jam waste but the mixture of whey, jam waste, and slurry was optimal for composting. 相似文献
22.
Pirilä E Maisi P Salo T Koivunen E Sorsa T 《Biochemical and biophysical research communications》2001,287(3):766-774
In situ zymography provides a tool to localize proteolytic activity in tissues in vivo. However, it has been difficult to discriminate between the proteases responsible for the detected activity. We used a selective tissue-permeable gelatinase inhibitor, the CTTHWGFTLC-peptide (CTT) in inflamed human gingiva. The CTT-peptide was evidenced to home, target to, and selectively inhibit the areas of gelatinolytic activity in inflamed human gingiva expressing MMP-2 and -9. Gelatinolytic activity, MMP-9 immunoreactivity, and mRNA expression as well as CD-45-positive inflammatory cells colocalized well in the inflamed human gingival connective tissue. Gelatinolytic activity corresponding to MMP-2 colocalized with laminin-5 gamma2-chain immunoreactivity and was detected in the close vicinity of the sulcular basement membrane region. Furthermore, the CTT-peptide inhibited beta-caseinolysis by human MMP-2 and MMP-9 as well as laminin-5 gamma2-chain degradation by MMP-2 in vitro. Thus, the CTT-peptide may prove to be a useful tool (i) to discriminate between gelatinolytic proteases detected by in situ zymography and (ii) to preventMMP-2-dependent induction of epithelial cell migration and gelatinase-dependent tissue destruction in inflammatory and malignant diseases. 相似文献
23.
24.
Ana Lucia Cordova-Kreylos Lorena E. Fernandez Marja Koivunen April Yang Lina Flor-Weiler Pamela G. Marrone 《Applied and environmental microbiology》2013,79(24):7669-7678
Isolate A396, a bacterium isolated from a Japanese soil sample demonstrated strong insecticidal and miticidal activities in laboratory bioassays. The isolate was characterized through biochemical methods, fatty acid methyl ester (FAME) analysis, sequencing of 16S rRNA, multilocus sequence typing and analysis, and DNA-DNA hybridization. FAME analysis matched A396 to Burkholderia cenocepacia, but this result was not confirmed by 16S rRNA or DNA-DNA hybridization. 16S rRNA sequencing indicated closest matches with B. glumae and B. plantarii. DNA-DNA hybridization experiments with B. plantarii, B. glumae, B. multivorans, and B. cenocepacia confirmed the low genetic similarity (11.5 to 37.4%) with known members of the genus. PCR-based screening showed that A396 lacks markers associated with members of the B. cepacia complex. Bioassay results indicated two mechanisms of action: through ingestion and contact. The isolate effectively controlled beet armyworms (Spodoptera exigua; BAW) and two-spotted spider mites (Tetranychus urticae; TSSM). In diet overlay bioassays with BAW, 1% to 4% (vol/vol) dilution of the whole-cell broth caused 97% to 100% mortality 4 days postexposure, and leaf disc treatment bioassays attained 75% ± 22% mortality 3 days postexposure. Contact bioassays led to 50% larval mortality, as well as discoloration, stunting, and failure to molt. TSSM mortality reached 93% in treated leaf discs. Activity was maintained in cell-free supernatants and after heat treatment (60°C for 2 h), indicating that a secondary metabolite or excreted thermostable enzyme might be responsible for the activity. Based on these results, we describe the novel species Burkholderia rinojensis, a good candidate for the development of a biocontrol product against insect and mite pests. 相似文献
25.
Nest predation and its avoidance are critical components of an individual's fitness and play an important role in life history evolution. Almost all studies on this topic have been observational, and thus have not been able to separate the effects of individual quality, habitat selection and predation risk of given nest sites from each other. More experimental studies on nest predation and breeding dispersal, therefore, are needed to avoid confusing interpretations of the results. In western Finland, pine marten (Martes martes) predation risk was experimentally simulated at the nests of Tengmalm's owls (Aegolius funereus) by using a caged American mink (Mustela vison) as a predator. Nests without exposure to a mink served as controls. In accordance with our predictions and earlier observational studies, males exposed to simulated predation risk increased nest-hole shift and breeding dispersal distances compared to control males. Nest-hole shift and long breeding dispersal distances probably decrease the risk of nest predation, because pine martens are known to revisit nest-holes they have found. 相似文献
26.
27.
Structural explanation for the role of Mn2+ in the activity of phi6 RNA-dependent RNA polymerase 下载免费PDF全文
Poranen MM Salgado PS Koivunen MR Wright S Bamford DH Stuart DI Grimes JM 《Nucleic acids research》2008,36(20):6633-6644
The biological role of manganese (Mn(2+)) has been a long-standing puzzle, since at low concentrations it activates several polymerases whilst at higher concentrations it inhibits. Viral RNA polymerases possess a common architecture, reminiscent of a closed right hand. The RNA-dependent RNA polymerase (RdRp) of bacteriophage 6 is one of the best understood examples of this important class of polymerases. We have probed the role of Mn(2+) by biochemical, biophysical and structural analyses of the wild-type enzyme and of a mutant form with an altered Mn(2+)-binding site (E491 to Q). The E491Q mutant has much reduced affinity for Mn(2+), reduced RNA binding and a compromised elongation rate. Loss of Mn(2+) binding structurally stabilizes the enzyme. These data and a re-examination of the structures of other viral RNA polymerases clarify the role of manganese in the activation of polymerization: Mn(2+) coordination of a catalytic aspartate is necessary to allow the active site to properly engage with the triphosphates of the incoming NTPs. The structural flexibility caused by Mn(2+) is also important for the enzyme dynamics, explaining the requirement for manganese throughout RNA polymerization. 相似文献
28.
Stefanidakis M Ruohtula T Borregaard N Gahmberg CG Koivunen E 《Journal of immunology (Baltimore, Md. : 1950)》2004,172(11):7060-7068
We have recently demonstrated that promatrix metalloproteinases (proMMPs), particularly proMMP-9, are potent ligands of the leukocyte beta(2) integrins. We studied here the complex formation between proMMP-9 and alpha(M)beta(2), the major MMP and integrin of neutrophils. On resting neutrophils, the proMMP-9/alpha(M)beta(2) complex was primarily detected in intracellular granules, but after cellular activation it became localized to the cell surface, as demonstrated by immunoprecipitation and double immunofluorescence. Further indication of the complex formation was that neutrophils and alpha(M)beta(2)-transfected L cells, but not the wild-type L cells or leukocyte adhesion deficiency cells, bound to immobilized proMMP-9 or its recombinant catalytic domain in a beta(2) integrin-dependent manner. Peptides that bound to the alpha(M) integrin-I domain and inhibited its complex formation with proMMP-9 prevented neutrophil migration in a transendothelial assay in vitro and in a thioglycolate-elicited peritonitis in vivo. These results suggest that the translocating proMMP-9/alpha(M)beta(2) complex may be part of the cell surface machinery guiding neutrophil migration. 相似文献
29.
Peptide inhibition of catalytic and noncatalytic activities of matrix metalloproteinase-9 blocks tumor cell migration and invasion 总被引:5,自引:0,他引:5
Migration of invasive cells appears to be dependent on matrix metalloproteinases (MMPs) anchored on the cell surface through integrins. We have previously demonstrated an interaction between the integrin alpha-subunit I domain and the catalytic domain of MMP-9. We now show that there is also an interaction between the integrin beta subunit and MMP-9. Using phage display, we have developed MMP-9 inhibitors that bind either to the MMP-9 catalytic domain, the collagen binding domain, or the C-terminal hemopexin-like domain. The C-terminal domain-binding peptide mimics an activation epitope in the stalk of the integrin beta chain and inhibits the association of MMP-9 C-terminal domain with alpha(V)beta(5) integrin. Unlike other MMP-9 binding peptides, it does not directly inhibit catalytic activity of MMP-9, but still prevents proenzyme activation and cell migration in vitro and tumor xenograft growth in vivo. We also find an association between MMP-9 and urokinase-plasminogen activator receptor and find that urokinase-plasminogen activator receptor is cleaved by MMP-9. Collectively, we have defined molecular details for several interactions mediated by the different MMP-9 domains. 相似文献