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21.
Daniel Wibberg Jochen Blom Christian Rückert Anika Winkler Andreas Albersmeier Alfred Pühler Andreas Schlüter Birgit E. Scharf 《Journal of biotechnology》2013
Sinorhizobium meliloti of the order Rhizobiales is a symbiotic nitrogen-fixing bacterium nodulating plants of the genera Medicago, Trigonella and Melilotus and hence is of great agricultural importance. In its free-living state it is motile and capable of modulating its movement patterns in response to chemical attractants. Here, the draft genome consisting of a circular chromosome, the megaplasmids pSymA and pSymB and three accessory plasmids of Sinorhizobium meliloti RU11/001, a model organism for flagellum structure, motility and chemotaxis, is reported. 相似文献
22.
Michele Tinti Lars Kiemer Stefano Costa Martin L. Miller Francesca Sacco Jesper V. Olsen Martina Carducci Serena Paoluzi Francesca Langone Christopher T. Workman Nikolaj Blom Kazuya Machida Christopher M. Thompson Mike Schutkowski Søren Brunak Matthias Mann Bruce J. Mayer Luisa Castagnoli Gianni Cesareni 《Cell reports》2013,3(4):1293-1305
Highlights? The recognition specificity of 70 SH2 domains is probed ? Recognition specificity diverges faster than sequence ? PepspotDB is a database of protein interactions mediated by SH2 domains 相似文献
23.
Margaret von Faber Gerda M. van der Weele Geertje van der Geest Jeanet W. Blom Nicolette van der Zouwe Ria Reis Roos C. van der Mast Jacobijn Gussekloo 《Tijdschrift voor gerontologie en geriatrie》2016,47(6):249-257
Background
To gain new insights for support for older people with low mood, we explored the perceptions of ‘screenpositive’ older people on underlying causes and possible solutions.Design and method
We conducted two in-depth interviews with 38 participants (≥77 years) who screened positive for depressive symptoms in general practice. To investigate the influence of the presence of complex health problems, we included 19 persons with and 19 without complex problems. Complex problems were defined as a combination of functional, somatic, psychological or social problems.Results
All participants used several cognitive, social or practical coping strategies. Four patterns emerged: mastery, acceptance, ambivalence, and need for support. Some participants, especially those with complex problems, were ambivalent about possible interventions.Conclusion
Most older participants perceived their coping strategies as sufficient. General practitioners can support self-management by exploring the (effectiveness of) personal coping strategies, providing information, elaborating on perceptions of risks and discussing alternative options with older persons.24.
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26.
Dimitra Sakoula Garrett J. Smith Jeroen Frank Rob J. Mesman Linnea F. M. Kop Pieter Blom Mike S. M. Jetten Maartje A. H. J. van Kessel Sebastian Lücker 《The ISME journal》2022,16(4):958
The advance of metagenomics in combination with intricate cultivation approaches has facilitated the discovery of novel ammonia-, methane-, and other short-chain alkane-oxidizing microorganisms, indicating that our understanding of the microbial biodiversity within the biogeochemical nitrogen and carbon cycles still is incomplete. The in situ detection and phylogenetic identification of novel ammonia- and alkane-oxidizing bacteria remain challenging due to their naturally low abundances and difficulties in obtaining new isolates from complex samples. Here, we describe an activity-based protein profiling protocol allowing cultivation-independent unveiling of ammonia- and alkane-oxidizing bacteria. In this protocol, 1,7-octadiyne is used as a bifunctional enzyme probe that, in combination with a highly specific alkyne-azide cycloaddition reaction, enables the fluorescent or biotin labeling of cells harboring active ammonia and alkane monooxygenases. Biotinylation of these enzymes in combination with immunogold labeling revealed the subcellular localization of the tagged proteins, which corroborated expected enzyme targets in model strains. In addition, fluorescent labeling of cells harboring active ammonia or alkane monooxygenases provided a direct link of these functional lifestyles to phylogenetic identification when combined with fluorescence in situ hybridization. Furthermore, we show that this activity-based labeling protocol can be successfully coupled with fluorescence-activated cell sorting for the enrichment of nitrifiers and alkane-oxidizing bacteria from complex environmental samples, enabling the recovery of high-quality metagenome-assembled genomes. In conclusion, this study demonstrates a novel, functional tagging technique for the reliable detection, identification, and enrichment of ammonia- and alkane-oxidizing bacteria present in complex microbial communities.Subject terms: Environmental microbiology, Sequencing, Microbiology 相似文献
27.
C4b-binding protein (C4BP) is a regulator of the classical complement pathway C3 convertase (C4bC2a complex). It is a disulfide-linked polymer of seven alpha-chains and a unique beta-chain; the alpha- and beta-chains are composed of eight and three complement control protein (CCP) domains, respectively. To elucidate the importance of the polymeric nature of C4BP and the structural requirements for the interaction between C4b and the alpha-chain, 19 recombinant C4BP variants were created. Six truncated monomeric variants, nine polymeric variants in which individual CCPs were deleted, and finally, four variants in which double alanine residues were introduced between CCPs were functionally characterized. The smallest truncated C4BP variant still active in regulating fluid phase C4b comprised CCP1-3. The monomeric variants were less efficient than polymeric C4BP in degrading C4b on cell surfaces. All three N-terminal CCP domains contributed to the binding of C4b and were important for full functional activity; CCP2 and CCP3 were the most important. The spatial arrangements of the first CCPs were found to be important, as introduction of alanine residues between CCPs 1 and 2, CCPs 2 and 3, and CCPs 3 and 4 resulted in functional impairment. The results presented here elucidate the structural requirements of individual CCPs of C4BP, as well as their spatial arrangements within and between subunits for expression of full functional activity. 相似文献
28.
Friedrich U Blom AM Dahlbäck B Villoutreix BO 《The Journal of biological chemistry》2001,276(26):24122-24128
Human activated protein C (APC) is a key component of a natural anticoagulant system that regulates blood coagulation. In vivo, the catalytic activity of APC is regulated by two serpins, alpha1-antitrypsin and the protein C inhibitor (PCI), the inhibition by the latter being stimulated by heparin. We have identified a heparin-binding site in the serine protease domain of APC and characterized the energetic basis of the interaction with heparin. According to the counter-ion condensation theory, the binding of heparin to APC is 66% ionic in nature and comprises four to six net ionic interactions. To localize the heparin-binding site, five recombinant APC variants containing amino acid exchanges in loops 37, 60, and 70 (chymotrypsinogen numbering) were created. As demonstrated by surface plasmon resonance, reduction of the electropositive character of loops 37 and 60 resulted in complete loss of heparin binding. The functional consequence was loss in heparin-induced stimulation of APC inhibition by PCI, whereas the PCI-induced APC inhibition in the absence of heparin was enhanced. Presumably, the former observations were due to the inability of heparin to bridge some APC mutants to PCI, whereas the increased inhibition of certain APC variants by PCI in the absence of heparin was due to reduced repulsion between the enzymes and the serpin. The heparin-binding site of APC was also shown to interact with heparan sulfate, albeit with lower affinity. In conclusion, we have characterized and spatially localized the functionally important heparin/heparan sulfate-binding site of APC. 相似文献
29.
Dabrowski K Lee KJ Rinchard J Ciereszko A Blom JH Ottobre JS 《Biochimica et biophysica acta》2001,1525(1-2):37-42
We investigated the role of gossypol isomers binding to blood plasma, seminal plasma and spermatozoa to elucidate gossypol anti-fertility action in the teleost fish, rainbow trout (Oncorhynchus mykiss). Growth and hematological indicators of males were depressed when fish meal protein in diets was completely replaced with cottonseed meal. The cottonseed meal contained equal proportions of (-) (47.8+/-1.6%) and (+) gossypol isomers. Concentrations of spermatozoa were decreased with increasing proportions of gossypol in diets (from 0.22% to 0.95%); however, sperm motility and fertilizing ability were not affected. In contrast to mammals, steroid hormone concentrations were not suppressed in fish given diets with gradual increase of gossypol level. Gossypol concentrations were 100-fold higher in blood plasma than in seminal plasma, confirming a barrier in gossypol transfer between the general circulation and the testis. Spermatozoa accumulated predominantly (+) enantiomer (65-75%) with decreasing proportions as dietary gossypol concentrations increased. Spermatozoa bound most of the gossypol contained in the semen; however, this did not result in impairment of the sperm motility apparatus. Teleost fish sperm rely on ATP stores that accumulate during maturation as a source of energy during activation. In addition, the duration of sperm movement is short in these fish. As such, we hypothesize that the major action of gossypol on mammalian sperm, which is uncoupling of oxidative phosphorylation, does not impair the energy supply required for flagellar beating in fish spermatozoa. 相似文献
30.