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The activity of the DNA repair enzyme hOGG1 can be directly modulated by ubiquinol
No full textThe DNA of human cells suffers about 1.000–100.000 oxidative lesions per day. One of the most common defects in this category is represented by 7,8-dihydro-8-oxoguanine. There are numerous exogenous effects on DNA that induce the intracellular generation of 7, 8-dihydro-8-oxoguanine. Therefore, a quantitatively sufficient repair of
all occurring oxidative damaged guanine bases is often only partially feasible, especially in advanced age. Inadequate removal of these damages can subsequently lead to mutations and thus to serious diseases. All these aspects represent a dangerous situation for an organism. However, it is suspected that the amount of the 8-
oxoguanine DNA glycosylase can be actively regulated on the level of gene expression by the redox-active properties of ubiquinol and thus its protein expression can be controlled. Using an real-time base excision repair assay including a melting curve analysis, the activity of the human 8-oxoguanine DNA glycosylase 1 was measured under the influence of ubiquinol. It was possible to observe a concentration-dependent increase in the activity of the 8-oxoguanine DNA glycosylase 1 under the influence of ubiquinol for the first time, both on
purified and commercially acquired enzyme as well as on enzyme isolated from mitochondria of human fibroblasts. An increase in activity of this enzyme based on a change in cellular redox state caused by ubiquinol could not be confirmed. In addition, an increased gene expression of 8-oxoguanine-DNA glycosylase 1 under
ubiquinol could not be observed. However, there was a change in bifunctionality in favor of an increased N-glycosylase activity and a direct interaction between ubiquinol and 8-oxoguanine DNA glycosylase 1. We suggest that ubiquinol contributes to the dissolution of a human 8-oxoguanine DNA glycosylase 1 end-product complex that forms after cutting into the sugar-phosphate backbone of the DNA with the resulting unsaturated 3′-phospho-α, β-aldehyde end and thereby inhibits further enzymatic steps
12 days of in vivo caloric reduction can improve important parameters of aging in humans
No full textCaloric reduction (CR) is considered as the most reasonable intervention to delay aging and age-related diseases. Numerous studies in various model organisms provide the main basis for this hypothesis. Human studies exist, but they differ widely in study design, characteristics of test persons and study outcome. In this study we investigated CR in humans on a molecular level to gain a better understanding in these processes. For that purpose, we analyzed human peripheral blood mononuclear cells of healthy people fasting according to F.X. Mayr. In a previous study our group could show a significantly improved DNA repair capacity after fasting. Here we were able to confirm these findings despite a slightly modified fasting therapy. Furthermore, the function of the mitochondrial respiratory chain and the mRNA levels of the mitochondria-associated genes SIRT3 and NDUFS1
were significantly affected by CR. However, these changes were only detectable in people who exhibited no improvement in DNA repair capacity. In contrast to that we could not observe any changes in ROS levels, mitochondrial DNA copy number and non-mitochondrial respiration. Altogether our results reveal that CR in form of F. X. Mayr therapy is able to positively influence several cellular parameters and especially mitochondrial function
Preparation and Compatibilization of PBS/Whey Protein Isolate Based Blends
Get PDFIn this paper the production of biopolymeric blends of poly(butylene succinate) PBS and plasticized whey protein (PWP), obtained from a natural by-product from cheese manufacturing, has been investigated for the production of films and/or sheets. In order to add the highest possible whey protein content, different formulations (from 30 to 50 wt.%) were studied. It was found that by increasing the amount of PWP added to PBS, the mechanical properties were worsened accordingly.
This trend was attributed to the low compatibility between PWP and PBS. Consequently, the effect of the addition of soy lecithin and glycerol monostearate (GMS) as compatibilizers was investigated
and compared to the use of whey protein modified with oleate and laurate groups obtained by Schotten-Baumann reaction. Soy lecithin and the Schotten-Baumann modified whey were effective in
compatibilizing the PWP/PBS blend. In fact, a significant increase in elastic modulus, tensile strength and elongation at break with respect to the not compatibilized blend was observed and the length of
aliphatic chains as well as the degree of modification of the Schotten–Baumann proteins affected the results. Moreover, thanks to DSC investigations, these compatibilizers were also found effective in
increasing the PBS crystallinity
EU research project BIOnTop. Research and development of more sustainable packaging concepts
No full textRapeseed proteins for technical applications: Processing, isolation, modification and functional properties – A review
No full textPlant proteins offer an interesting resource for the growing bio-economy of the 21st century, as they present a renewable resource with a variety of functional properties, such as foaming, emulsification and film-forming. Rapeseed proteins can be isolated as high-value components from residual materials of oilseed processing. Feed and food use, though currently being the primary area of research, is limited due to residual anti-nutritive components. Thus, the application of rapeseed protein preparations in the technical (non-food) industry, as alternatives to petro-based chemicals, is of great interest. The present review gives an overview of rapeseed processing with an emphasis on alternative defatting methods. Protein extraction and isolation studies are compared with a focus on raw material properties, processes, and the resulting protein yields. Functional properties and methods for their modification are discussed. Finally, examples for the application of rapeseed proteins in the technical industry are presented
Wie werden E-Autos für Landbevölkerung attraktiv?
No full textAuf dem Land gibt es deutlich mehr Vorbehalte gegen die Elektromobilität als in der Stadt. Oft wird Wissen durch "Mythen" ersetzt. Was also muss man tun, um auch der Landbevölkerung die E-Mobilität schmackhaft zu machen? Damit haben sich jetzt Studenten der Hochschule Albstadt-Sigmaringen beschäftigt. Als Steuermann der Projektarbeit fungierte Professor Wilfried Funk. Er berichtet exklusiv im Südfinder darüber
Transferable Extended-Spectrum β-Lactamase (ESBL) Plasmids in Enterobacteriaceae from Irrigation Water
Get PDFExtended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae are classified as serious threats to human health by the U.S. Centers for Disease Control and Prevention. Water used for irrigation of fresh produce can transmit such resistant bacteria directly to edible plant parts. We screened ESBL-producing Escherichia coli, Enterobacter cloacae, and Citrobacter freundii isolated from irrigation water for their potential to transmit resistance to antibiotic-susceptible E. coli. All strains were genome-sequenced and tested in vitro for transmission of resistance to third-generation cephalosporins on solid agar as well as in liquid culture. Of the 19 screened isolates, five ESBL-producing E. coli were able to transfer resistance with different efficiency to susceptible recipient E. coli. Transconjugant strains were sequenced for detection of transferred antibiotic resistance genes (ARGs) and compared to the known ARG pattern of their respective donors. Additionally, phenotypic resistance patterns were obtained for both transconjugant and corresponding donor strains, confirming ESBL-producing phenotypes of all obtained transconjugants
Grafting of Fatty Acids on Polyvinyl Alcohol: Effects on Surface Energy and Adhesion Strength of Acrylic Pressure Sensitive Adhesives
Get PDFChemical grafting with fatty acid chlorides is known to reduce the surface energy of polymer substrates. The aim of this study was to evaluate the effect of different grafting parameters on functional properties such as the surface energy of grafted substrates and adhesion of acrylic pressure sensitive adhesives (PSA) on those substrates in dependence of storage time. Therefore, two substrates, paper and polyethylene terephthalate (PET), were coated with polyvinyl alcohol (PVOH). The PVOH showed similar degrees of hydrolysis but different molecular weights. Fatty acid chlorides (palmitoyl chloride, stearoyl chloride) were grafted on pure PET, pure paper, PVOH coated
paper, and PVOH coated PET. On these samples, roughness was measured and peel strength and surface energy were determined over storage time. Peel strength was observed to increase with roughness. The chain length of fatty acid chlorides and storage time did not majorly influence peel strength
