Nitrogen fixation is a key process that sustains life on Earth. Nitrogenase is the sole enzyme capable of fixing nitrogen under ambient conditions. Extensive research efforts have been dedicated to elucidating the enzyme mechanism and its artificial activation through high applied voltage, photochemistry, or strong reducing agents.
View Article and Find Full Text PDFThe advances in biotic-abiotic interfaced systems open new directions toward bioanalytics and biocatalysis applications. Conjugating the unique electronic and optic properties of nanoelements with the high selectivity and extraordinary catalytic abilities of biotic materials holds great promise to gain superior new features. Herein, we present a wide scope of biotic-abiotic research, with key examples for its utilization in bioanalytics applications as well as in biocatalysis.
View Article and Find Full Text PDFLactate sensing has high importance for metabolic disease diagnostics, food spoilage, sports medicine, or the construction of biofuel cell devices. Therefore, continuous lactate sensing devices which enable accurate detection should be developed. Here we present the overexpression and utilization of FMN-lactate dehydrogenase from Saccharomyces cerevisiae for oxygen-insensitive, continuous amperometric lactate biosensing.
View Article and Find Full Text PDFEfficient oxygen-reducing biocatalysts are essential for the development of biofuel cells or photo-bioelectrochemical applications. Bilirubin oxidase (BOD) is a promising biocatalyst for oxygen reduction processes at neutral pH and low overpotentials. BOD has been extensively investigated over the last few decades.
View Article and Find Full Text PDFFlavin-dependent glucose dehydrogenases (FAD-GDH) are oxygen-independent enzymes with high potential to be used as biocatalysts in glucose biosensing applications. Here, we present the construction of an amperometric biosensor and a biofuel cell device, which are based on a thermophilic variant of the enzyme originated from . The enzyme overexpression in and its isolation and performance in terms of maximal bioelectrocatalytic currents were evaluated.
View Article and Find Full Text PDFNovel protein-based nanovehicles offer alternatives to fat for delivery of lipophilic bioactives (nutraceuticals and drugs), yet they raise important questions regarding the bioavailability and absorption mechanism of the bioactive without fat. To provide answers, we chose vitamin D (VD) as a model lipophilic-nutraceutical, re-assembled casein-micelles (rCM) as model protein-based nanovehicles, and non-fat yoghurt as a model food. We prepared three yoghurt formulations: 3% fat with VD dissolved in milk-fat, non-fat and 3% fat, both latter enriched with VD within rCM.
View Article and Find Full Text PDFPhoto-bioelectrochemical cells that are based on photosynthetic proteins are drawing increased attention for both fundamental and applied research. While novel photosynthetic based systems have been introduced, further optimization in terms of stability and efficiency is required. Photosystem I has been utilized extensively in bioelectronic devices, often in conjugation with viologen moieties which act as electron acceptors.
View Article and Find Full Text PDFThe construction of bias- and donor-free photobioelectrochemical cells for the generation of light-triggered electrical power is presented. The developed oxygen reduction biocathodes are based on bilirubin oxidase (BOD) that originates from Myrothecium verrucaria (MvBOD) and a thermophilic Bacillus pumilus (BpBOD). Methods to entrap the BOD with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) redox molecules in a polydopamine layer are presented.
View Article and Find Full Text PDFDuring cell division, the inheritance of a functional endoplasmic reticulum (ER) is ensured by the endoplasmic reticulum stress surveillance (ERSU) pathway. Activation of ERSU causes the septin ring to mislocalize, which blocks ER inheritance and cytokinesis. Here, we uncover that the septin ring in fact translocates to previously utilized cell division sites called cytokinetic remnants (CRMs).
View Article and Find Full Text PDFThe pandemic of vitamin D (VD) deficiency, and the global rise in obesity stimulate a need for staple low-fat foods and beverages enriched with VD. In light of consumer demand for a clean label, the use of natural endogenous food ingredients as delivery vehicles is of great interest. To this end, re-assembled casein micelles (rCM) have been shown to help retain VD during processing and shelf life and provide high bioavailability in low-fat milk and non-fat yoghurt.
View Article and Find Full Text PDFViruses are by definition fully dependent on the cellular translation machinery, and develop diverse mechanisms to co-opt this machinery for their own benefit. Unlike many viruses, human cytomegalovirus (HCMV) does suppress the host translation machinery, and the extent to which translation machinery contributes to the overall pattern of viral replication and pathogenesis remains elusive. Here, we combine RNA sequencing and ribosomal profiling analyses to systematically address this question.
View Article and Find Full Text PDFIt is well established that import of proteins into mitochondria can occur after their complete synthesis by cytosolic ribosomes. Recently, an additional model was revived, proposing that some proteins are imported co-translationally. This model entails association of ribosomes with the mitochondrial outer membrane, shown to be mediated through the ribosome-associated chaperone nascent chain-associated complex (NAC).
View Article and Find Full Text PDFSemin Immunopathol
November 2014
The herpesvirus human cytomegalovirus (HCMV) infects the majority of the world's population, leading to severe diseases in millions of newborns and immunocompromised adults annually. During infection, HCMV extensively manipulates cellular gene expression to maintain conditions favorable for efficient viral propagation. Identifying the pathways that the virus relies on or subverts is of great interest as they have the potential to provide new therapeutic targets and to reveal novel principles in cell biology.
View Article and Find Full Text PDFPeroxisomes are ubiquitous and dynamic organelles that house many important pathways of cellular metabolism. In recent years it has been demonstrated that mitochondria are tightly connected with peroxisomes and are defective in several peroxisomal diseases. Indeed, these two organelles share metabolic routes as well as resident proteins and, at least in mammals, are connected via a vesicular transport pathway.
View Article and Find Full Text PDFThe endoplasmic reticulum (ER) is a large, multifunctional and essential organelle. Despite intense research, the function of more than a third of ER proteins remains unknown even in the well-studied model organism Saccharomyces cerevisiae. One such protein is Spf1, which is a highly conserved, ER localized, putative P-type ATPase.
View Article and Find Full Text PDFWe investigated the mechanisms of the protection conferred by sugars to epigallocatechin-3-gallate (EGCG) against deterioration. Additionally, we present a rapid method for evaluating the deterioration rate of EGCG using absorbance spectroscopy. We found that various sugars provided different levels of protection at identical weight percentage, and the combination of sugars and β-lactoglobulin nanocomplexes provided greater protection for EGCG than each protective component alone.
View Article and Find Full Text PDFIn human multiple myeloma (MM), the tumor cells exhibit strict dependence on bone marrow (BM) stromal elements. It has been suggested that, in turn, MM cells modify multipotent stromal cells (MSCs), diverting them to support the myeloma. We investigated MM-derived MSCs by comparing their toll-like receptor (TLR) responses to those of MSCs derived from healthy controls.
View Article and Find Full Text PDFMethods Mol Biol
January 2012
High-throughput methodologies have created new opportunities for studying biological phenomena in an unbiased manner. Using automated cell manipulations and microscopy platforms, it is now possible to easily screen entire genomes for genes that affect any cellular process that can be visualized. The onset of these methodologies promises that the near future will bring with it a more comprehensive and richly integrated understanding of complex and dynamic cellular structures and processes.
View Article and Find Full Text PDFAn efficient immune response against tumours depends on a well-orchestrated function of integrated components, but is finally exerted by effector tumour-infiltrating lymphocytes (TIL). We have previously reported that homophilic CEACAM1 interactions inhibit the specific killing and interferon-gamma (IFN-gamma) release activities of natural killer cells and TIL. In this study a model for the investigation of melanoma cells surviving long coincubation with antigen-specific TIL is reported.
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