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91.
Susanne Melzer Gudrun Winter Kathrin Jäger Thomas Hübschmann Gerd Hause Frank Syrowatka Hauke Harms Attila Tárnok Susann Müller 《Microbial biotechnology》2015,8(3):379-391
Bacterial growth is often difficult to estimate beyond classical cultivation approaches. Low cell numbers, particles or coloured and dense media may disturb reliable growth assessment. Further difficulties appear when cells are attached to surfaces and detachment is incomplete. Therefore, flow cytometry was tested and used for analysis of bacterial growth on the single‐cell level. Shewanella putrefaciens was cultivated as a model organism in planktonic or biofilm culture. Materials of smooth and rough surfaces were used for biofilm cultivation. Both aerobic and anaerobic as well as feast and famine conditions were applied. Visualization of growth was also done using Environmental Scanning and Phase Contrast Microscopy. Bioinformatic tools were applied for data interpretation. Cytometric proliferation patterns based on distributions of DNA contents per cell corresponded distinctly to the various lifestyles, electron acceptors and substrates tested. Therefore, cell cycling profiles of S. putrefaciens were found to mirror growth conditions. The cytometric patterns were consistently detectable with exception of some biofilm types whose resolution remained challenging. Corresponding heat maps proved to be useful for clear visualization of growth behaviour under all tested conditions. Therefore, flow cytometry in combination with bioinformatic tools proved to be powerful means to determine various growth states of S. putrefaciens, even in constrained environments. The approach is universal and will also be applicable for other bacterial species. 相似文献
92.
János Galambos Gábor Wágner Katalin Nógrádi Attila Bielik László Molnár Amrita Bobok Attila Horváth Béla Kiss Sándor Kolok József Nagy Dalma Kurkó Mónika L. Bakk Mónika Vastag Katalin Sághy István Gyertyán Krisztina Gál István Greiner Zsolt Szombathelyi György M. Keserű György Domány 《Bioorganic & medicinal chemistry letters》2010,20(15):4371-4375
Hit-to-lead optimization of a HTS hit led to new carbamoyloxime derivatives. After identification of an advanced hit (8d) the CYP enzyme inhibitory activity of this class of compounds was successfully eliminated. Systematic exploration of different parts of the advanced hit led us to some promising lead compounds with mGluR5 affinities comparable to that of MPEP. 相似文献
93.
Gábor Wágner Csaba Wéber Olga Nyéki Katalin Nógrádi Attila Bielik László Molnár Amrita Bobok Attila Horváth Béla Kiss Sándor Kolok József Nagy Dalma Kurkó Krisztina Gál István Greiner Zsolt Szombathelyi György M. Keserű György Domány 《Bioorganic & medicinal chemistry letters》2010,20(12):3737-3741
Here we report the discovery and early SAR of a series of mGluR5 negative allosteric modulators (NAMs). Starting from a moderately active HTS hit we synthesized 3,5-disubstituted-oxadiazoles and tetrazoles as mGluR5 NAMs. Based on the analysis of ligand efficiency and lipophilic efficiency metrics we identified a promising lead candidate as a starting point for further optimization. 相似文献
94.
Attila Vig Attila Igloi Nora Adanyi Gyongyi Gyemant Csaba Csutoras Attila Kiss 《Bioprocess and biosystems engineering》2010,33(8):947-952
An amperometric detector and an enzymatic reaction were combined for the measurement of l-ascorbic acid. The enzyme cell (containing immobilized ascorbate oxidase) was connected to a flow injection analyzer (FIA)
system with a glassy carbon electrode as an amperometric detector. During optimization and measurements two sample injectors
were used, one before and one after the enzyme cell, thus eliminating the background interferences. Subtraction of the signal
area given in the presence of enzyme from the one given in the absence of enzyme was applied for measuring analyte concentrations
and calibration at 400 mV. Analysis capacity of system is 25 samples/hour. The relative standard deviation (RSD) was below
5% (5 times repeated, 400 μmol/L conc.), linearity up to 400 μmol/L, limit of detection (LOD) 5 μmol/L, fitting of calibration
curve in 25–400 μmol/L range was R
2 = 0.99. 相似文献
95.
Signaling cascades, in addition to proteins with obvious signaling-relevant activities (e.g. protein kinases or receptors), also employ dedicated 'inactive' proteins whose functions appear to be the organization of the former components into higher order complexes through protein-protein interactions. The core function of signaling adaptors, anchors and scaffolds is the recruitment of proteins into one macromolecular complex. Several recent studies have demonstrated that the recruiter and the recruited molecules mutually influence each other in a scaffolded complex. This yields fundamentally novel properties for the signaling complex as a whole. Because these are not merely additive to the properties of the individual components, scaffolded signaling complexes may behave as functionally distinct modules. 相似文献
96.
97.
98.
Ribiczey P Tordai A Andrikovics H Filoteo AG Penniston JT Enouf J Enyedi A Papp B Kovács T 《Cell calcium》2007,42(6):590-605
In this work we demonstrate a differentiation-induced up-regulation of the expression of plasma membrane Ca2+ATPase (PMCA) isoforms being present in various gastric/colon cancer cell types. We found PMCA1b as the major isoform in non-differentiated cancer cell lines, whereas the expression level of PMCA4b was significantly lower. Cell differentiation initiated with short chain fatty acids (SCFAs) and trichostatin A, or spontaneous differentiation of post-confluent cell cultures resulted in a marked induction of PMCA4b expression, while only moderately increased PMCA1b levels. Up-regulation of PMCA4b expression was demonstrated both at the protein and mRNA levels, and closely correlated with the induction of established differentiation markers. In contrast, the expression level of the Na+/K+-ATPase or that of the sarco/endoplasmic reticulum Ca2+ATPase 2 protein did not change significantly under these conditions. In membrane vesicles obtained from SCFA-treated gastric/colon cancer cells a marked increase in the PMCA-dependent Ca2+ transport activity was observed, indicating a general increase of PMCA function during the differentiation of these cancer cells. Because various PMCA isoforms display distinct functional characteristics, we suggest that up-regulated PMCA expression, together with a major switch in PMCA isoform pattern may significantly contribute to the differentiation of gastric/colon cancer cells. The analysis of PMCA expression may provide a new diagnostic tool for monitoring the tumor phenotype. 相似文献
99.
Weickert MO Loeffelholz CV Roden M Chandramouli V Brehm A Nowotny P Osterhoff MA Isken F Spranger J Landau BR Pfeiffer AF Möhlig M 《American journal of physiology. Endocrinology and metabolism》2007,293(4):E1078-E1084
Liver fatty acid-binding protein (L-FABP) is a highly conserved key factor in lipid metabolism. Amino acid replacements in L-FABP might alter its function and thereby affect glucose metabolism in lipid-exposed subjects, as indicated by studies in L-FABP knockout mice. Amino acid replacements in L-FABP were investigated in a cohort of 1,453 Caucasian subjects. Endogenous glucose production (EGP), gluconeogenesis, and glycogenolysis were measured in healthy carriers of the only common Thr(94)-to-Ala amino acid replacement (Ala/Ala(94)) vs. age-, sex-, and BMI-matched wild-type (Thr/Thr(94)) controls at baseline and after 320-min lipid/heparin-somatostatin-insulin-glucagon clamps (n = 18). Whole body glucose disposal was further investigated (subset; n = 13) using euglycemic-hyperinsulinemic clamps without and with lipid/heparin infusion. In the entire cohort, the only common Ala/Ala(94) mutation was significantly associated with reduced body weight, which is in agreement with a previous report. In lipid-exposed, individually matched subjects there was a genotype vs. lipid-treatment interaction for EGP (P = 0.009) driven mainly by reduced glycogenolysis in Ala/Ala(94) carriers (0.46 +/- 0.05 vs. 0.59 +/- 0.05 mgxkg(-1)xmin(-1), P = 0.013). The lipid-induced elevation of plasma glucose levels was smaller in Ala/Ala(94) carriers compared with wild types (P < 0.0001). Whole body glucose disposal was not different between lipid-exposed L-FABP genotypes. In summary, the Ala/Ala(94)-mutation contributed significantly to reduced glycogenolysis and less severe hyperglycemia in lipid-exposed humans and was further associated with reduced body weight in a large cohort. Data clearly show that investigation of L-FABP phenotypes in the basal overnight-fasted state yielded incomplete information, and a challenge test was essential to detect phenotypical differences in glucose metabolism between L-FABP genotypes. 相似文献
100.
Sipilä L Ruotsalainen H Sormunen R Baker NL Lamandé SR Vapola M Wang C Sado Y Aszodi A Myllylä R 《The Journal of biological chemistry》2007,282(46):33381-33388
Most lysines in type IV and VI collagens are hydroxylated and glycosylated, but the functions of these unique galactosylhydroxylysyl and glucosylgalactosylhydroxylysyl residues are poorly understood. The formation of glycosylated hydroxylysines is catalyzed by multifunctional lysyl hydroxylase 3 (LH3) in vivo, and we have used LH3-manipulated mice and cells as models to study the function of these carbohydrates. These hydroxylysine-linked carbohydrates were shown recently to be indispensable for the formation of basement membranes (Ruotsalainen, H., Sipil?, L., Vapola, M., Sormunen, R., Salo, A. M., Uitto, L., Mercer, D. K., Robins, S. P., Risteli, M., Aszodi, A., F?ssler, R., and Myllyl?, R. (2006) J. Cell Sci. 119, 625-635). Analysis of LH3 knock-out embryos and cells in this work indicated that loss of glycosylated hydroxylysines prevents the intracellular tetramerization of type VI collagen and leads to impaired secretion of type IV and VI collagens. Mice lacking the LH activity of LH3 produced slightly underglycosylated type IV and VI collagens with abnormal distribution. The altered distribution and aggregation of type VI collagen led to similar ultrastructural alterations in muscle to those detected in collagen VI knockout and some Ullrich congenital muscular dystrophy patients. Our results provide new information about the function of hydroxylysine-linked carbohydrates of collagens, indicating that they play an important role in the secretion, assembly, and distribution of highly glycosylated collagen types. 相似文献