Search results for " SPECT"

Anti-inflammatory tetraquinane diterpenoids from a Crinipellis species.

2016

The small pro-inflammatory 10kDa chemokine CXCL10 (Interferon-inducible protein 10, IP-10) plays an important role in mediating immune responses through the activation and recruitment of leukocytes such as T cells, eosinophils, monocytes and NK cells to the sites of inflammation. Elevated levels of CXCL10 have been associated with chronic inflammatory and infectious diseases and therefore CXCL10 represents an attractive target for the development of new anti-inflammatory drugs. In a search for anti-inflammatory compounds from fungi inhibiting the inducible CXCL10 promoter activity, four new tetraquinane diterpenoids, crinipellin E (1), crinipellin F (2), crinipellin G (3) and crinipellin H …

Proton Leakage Is Sensed by IM30 and Activates IM30-Triggered Membrane Fusion

2020

The inner membrane-associated protein of 30 kDa (IM30) is crucial for the development and maintenance of the thylakoid membrane system in chloroplasts and cyanobacteria. While its exact physiological function still is under debate, it has recently been suggested that IM30 has (at least) a dual function, and the protein is involved in stabilization of the thylakoid membrane as well as in Mg2+-dependent membrane fusion. IM30 binds to negatively charged membrane lipids, preferentially at stressed membrane regions where protons potentially leak out from the thylakoid lumen into the chloroplast stroma or the cyanobacterial cytoplasm, respectively. Here we show in vitro that IM30 membrane binding…

LipidMS: An R Package for Lipid Annotation in Untargeted Liquid Chromatography-Data Independent Acquisition-Mass Spectrometry Lipidomics.

2018

High resolution LC-MS untargeted lipidomics using data independent acquisition (DIA) has the potential to increase lipidome coverage, as it enables the continuous and unbiased acquisition of all eluting ions. However, the loss of the link between the precursor and the product ions combined with the high dimensionality of DIA data sets hinder accurate feature annotation. Here, we present LipidMS, an R package aimed to confidently identify lipid species in untargeted LC-DIA-MS. To this end, LipidMS combines a coelution score, which links precursor and fragment ions with fragmentation and intensity rules. Depending on the MS evidence reached by the identification function survey, LipidMS provi…

Analysis of RNA modifications by liquid chromatography–tandem mass spectrometry

2016

The analysis of RNA modifications is of high importance in order to address a wide range of biological questions. Therefore, a highly sensitive and accurate method such as liquid chromatography-tandem mass spectrometry (LC-MS/MS) has to be available. By using different LC-MS/MS procedures, it is not only possible to quantify very low amounts of RNA modifications, but also to detect probably unknown modified nucleosides. For these cases the dynamic multiple reaction monitoring and the neutral loss scan are the most common techniques. Here, we provide the whole workflow for analyzing RNA samples regarding their modification content. This includes an equipment list, the preparation of required…

Mass Spectrometry Imaging Differentiates Chromophobe Renal Cell Carcinoma and Renal Oncocytoma with High Accuracy

2020

Background: While subtyping of the majority of malignant chromophobe renal cell carcinoma (cRCC) and benign renal oncocytoma (rO) is possible on morphology alone, additional histochemical, immunohistochemical or molecular investigations are required in a subset of cases. As currently used histochemical and immunohistological stains as well as genetic aberrations show considerable overlap in both tumors, additional techniques are required for differential diagnostics. Mass spectrometry imaging (MSI) combining the detection of multiple peptides with information about their localization in tissue may be a suitable technology to overcome this diagnostic challenge. Patients and Methods: Formalin…

Advanced Glycation End Products (AGEs): Biochemistry, Signaling, Analytical Methods, and Epigenetic Effects

2020

The advanced glycation end products (AGEs) are organic molecules formed in any living organisms with a great variety of structural and functional properties. They are considered organic markers of the glycation process. Due to their great heterogeneity, there is no specific test for their operational measurement. In this review, we have updated the most common chromatographic, colorimetric, spectroscopic, mass spectrometric, and serological methods, typically used for the determination of AGEs in biological samples. We have described their signaling and signal transduction mechanisms and cell epigenetic effects. Although mass spectrometric analysis is not widespread in the detection of AGEs…

Ethanol Controls the Self-Assembly and Mesoscopic Properties of Human Insulin Amyloid Spherulites.

2018

Protein self-assembly into amyloid fibrils or highly hierarchical superstructures is closely linked to neurodegenerative pathologies as Alzheimer's and Parkinson's diseases. Moreover, protein assemblies also emerged as building blocks for bioinspired nanostructured materials. In both the above mentioned fields, the main challenge is to control the growth and properties of the final protein structure. This relies on a more fundamental understanding of how interactions between proteins can determine structures and functions of biomolecular aggregates. Here, we identify a striking effect of the hydration of the single human insulin molecule and solvent properties in controlling hydrophobicity/…

Secondary structure and dynamics study of the intrinsically disordered silica-mineralizing peptide P5S3during silicic acid condensation and silica de…

2017

The silica forming repeat R5 of sil1 from Cylindrotheca fusiformis was the blueprint for the design of P5 S3 , a 50-residue peptide which can be produced in large amounts by recombinant bacterial expression. It contains 5 protein kinase A target sites and is highly cationic due to 10 lysine and 10 arginine residues. In the presence of supersaturated orthosilicic acid P5 S3 enhances silica-formation whereas it retards the dissolution of amorphous silica (SiO2 ) at globally undersaturated concentrations. The secondary structure of P5 S3 during these 2 processes was studied by circular dichroism (CD) spectroscopy, complemented by nuclear magnetic resonance (NMR) spectroscopy of the peptide in …

Specific and highly efficient condensation of GC and IC DNA by polyaza pyridinophane derivatives

2018

Abstract Two bis-polyaza pyridinophane derivatives and their monomeric reference compounds revealed strong interactions with ds-DNA and RNA. The bis-derivatives show a specific condensation of GC- and IC-DNA, which is almost two orders of magnitude more efficient than the well-known condensation agent spermine. The type of condensed DNA was identified as ψ-DNA, characterized by the exceptionally strong CD signals. At variance to the almost silent AT(U) polynucleotides, these strong CD signals allow the determination of GC-condensates at nanomolar nucleobase concentrations. Detailed thermodynamic characterisation by ITC reveals significant differences between the DNA binding of the bis-deriv…

2017

Functional near infrared spectroscopy (fNIRS) is a promising neuroimaging method for investigating networks of cortical regions over time. We propose a directed effective connectivity method (TPDC) allowing the capture of both time and frequency evolution of the brain’s networks using fNIRS data acquired from healthy subjects performing a continuous finger-tapping task. Using this method we show the directed connectivity patterns among cortical motor regions involved in the task and their significant variations in the strength of information flow exchanges. Intra and inter-hemispheric connections during the motor task with their temporal evolution are also provided. Characterisation of the …