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Ayseguel Temiz Artmann

Bio: Ayseguel Temiz Artmann is an academic researcher from RWTH Aachen University. The author has contributed to research in topics: Protein aggregation. The author has an hindex of 1, co-authored 1 publications receiving 18 citations.

Papers
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TL;DR: The ATP effect on protein aggregation was ambiguous: ATP alone had no effect on the protein’s thermal stability but it facilitated protein‘s destabilization in the presence of nitric oxide.
Abstract: Background and objective Regulating protein function in the cell by small molecules, provide a rapid, reversible and tunable tool of metabolic control. However, due to its complexity the issue is poorly studied so far. The effects of small solutes on protein behavior can be studied by examining changes of protein secondary structure, in its hydrodynamic radius as well as its thermal aggregation. The study aim was to investigate effects of adenosine-5’-triphosphate (ATP), spermine NONOate (NO donor) as well as sodium/potassium ions on thermal aggregation of albumin and hemoglobin. To follow aggregation of the proteins, their diffusion coefficients were measured by quasi-elastic light scattering (QELS) at constant pH (7.4) in the presence of solutes over a temperature range from 25°C to 80°C.

18 citations


Cited by
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Journal ArticleDOI
TL;DR: A simple counting strategy based on single-molecule localization microscopy to super-resolve protein structures in intact cells and basic quantitative evaluation that is capable of reporting the oligomeric state of dense, membrane-bound protein complexes is addressed.
Abstract: Probing the oligomeric state of abundant molecules, such as membrane proteins in intact cells, is essential, but has not been straightforward. We address this challenge with a simple counting strategy that is capable of reporting the oligomeric state of dense, membrane-bound protein complexes. It is based on single-molecule localization microscopy to super-resolve protein structures in intact cells and basic quantitative evaluation. We validate our method with membrane-bound monomeric CD86 and dimeric cytotoxic T-lymphocyte-associated protein as model proteins and confirm their oligomeric states. We further detect oligomerization of CD80 and vesicular stomatitis virus glycoprotein and propose coexistence of monomers and dimers for CD80 and trimeric assembly of the viral protein at the cell membrane. This approach should prove valuable for researchers striving for reliable molecular counting in cells.

153 citations

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TL;DR: The interplay of cellular physiology and environment at a single-cell level is explored, and biological basics that govern the functional state of the cell are reviewed and put them in context with physical fundamentals that shape the extracellular environment.
Abstract: Summary Life is based on the cell as the elementary replicative and self-sustaining biological unit. Each single cell constitutes an independent and highly dynamic system with a remarkable individuality in a multitude of physiological traits and responses to environmental fluctuations. However, with traditional population-based cultivation set-ups, it is not possible to decouple inherent stochastic processes and extracellular contributions to phenotypic individuality for two central reasons: the lack of environmental control and the occlusion of single-cell dynamics by the population average. With microfluidic single-cell analysis as a new cell assay format, these issues can now be addressed, enabling cultivation and time-resolved analysis of single cells in precisely manipulable extracellular environments beyond the bulk. In this article, we explore the interplay of cellular physiology and environment at a single-cell level. We review biological basics that govern the functional state of the cell and put them in context with physical fundamentals that shape the extracellular environment. Furthermore, the significance of single-cell growth rates as pivotal descriptors for global cellular physiology is discussed and highlighted by selected studies. These examples illustrate the unique opportunities of microfluidic single-cell cultivation in combination with growth rate analysis, addressing questions of fundamental bio(techno)logical interest.

46 citations

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TL;DR: In this paper, an experimental investigation is conducted to quantify the turbulent mixing of multiphase flows inside a flat-panel photobioreactors and its consequential effects on the performance of the PBR for algae cultivation.
Abstract: Keeping an appropriate mixing state of the multiphase flows in photobioreactors (PBRs) is a key issue for the optimal design and operation of the PBRs. In the present study, an experimental investigation is conducted to quantify the turbulent mixing of multiphase flows inside a flat-panel PBR and its consequential effects on the performance of the PBR for algae cultivation. While a high-resolution particle image velocity (PIV) system is used to achieve detailed flow field measurements to quantify the unsteady behaviors of the multiphase flows and turbulent mixing inside the PBR, algae cultures are also grown in the same PBR under the same test conditions. Detailed flow field measurement results are correlated with the algae growth performance in order to elucidate the underlying physics and explore/optimize design paradigms. The measurement results reveal that even though the airflow rate that is supplied to the PBR plays a dominant role in determining the characteristics of the turbulent mixing in the PBR, the geometric positioning of the aeration inlets also significantly contributes to the turbulent mixing. These differences in turbulent mixing cause differences in algae productivity within the PBR, clearly effecting efficiency of the PBR.

27 citations

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TL;DR: Cadmium toxicity was investigated in micro-algae Chlorella pyrenoidosa and Scenedesmus acutus exposed to various concentrations of Cd for 96 h, and the inhibitory and toxic effects of C d2+ on growth and photosynthetic parameters of algae were demonstrated.

24 citations

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TL;DR: The optimized assay can specifically detect microRNAs in spiked samples at concentrations as low as 1 pM and from as little as 100 ng of total RNA in 2 h, correlated well with results generated by qPCR when the authors profiled a select number of breast cancer related micro RNAs in a total RNA sample.
Abstract: The detection and profiling of microRNAs are of great interest in disease diagnosis and prognosis. In this paper, we present a method for the rapid amplification-free detection of microRNAs from total RNA samples. In a two-step sandwich assay approach, fluorescently labeled reporter probes were first hybridized with their corresponding target microRNAs. The reaction mix was then added to a microarray to enable their specific capture and detection. Reporter probes were Tm equalized, enabling specificity by adjusting the length of the capture probe while maintaining the stabilizing effect brought about by coaxial base stacking. The optimized assay can specifically detect microRNAs in spiked samples at concentrations as low as 1 pM and from as little as 100 ng of total RNA in 2 h. The detection signal was linear between 1 and 100 pM (R2 = 0.99). Our assay data correlated well with results generated by qPCR when we profiled a select number of breast cancer related microRNAs in a total RNA sample.

23 citations