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Gly-His-Thr-Asp-Amide, an Insulin-Activating Peptide from the Human Pancreas Is a Strong Cu(II) but a Weak Zn(II) Chelator
No full textThe Cu(II) and Zn(II) binding abilities of Gly-His-Thr-Asp-amide (GHTD-am), a tetrapeptide coreleased from the pancreas along with insulin, were studied using UV-vis and circular dichroism spectroscopies, potentiometry, and calorimetry. GHTD-am is a very strong Cu(II) chelator, forming a three-nitrogen complex with a conditional affinity constant C K at pH 7.4 of 4.5 × 10^12 M^-1. The fourth coordination site can be occupied by a solvent molecule or a ternary ligand, such as imidazole, with C K on the order of several hundred reciprocal molar. The Zn(II) binding ability of GHTD-am is relatively weak, with C K values at pH 7.4 of 3.0 × 10^4 and 2.0 × 10^3 M-1 for the first and second GHTD-am molecule coordinated, respectively. These results are discussed in light of the modes of interactions of Zn(II) and Cu(II) ions with insulin. A direct effect of GHTD-am on the Zn(II) interactions with insulin is unlikely, but its Cu(II) complex may have a biological relevance because of its high affinity and ability to form ternary complexes
Spontaneous DNA damage to the nuclear genome promotes senescence,redox imbalance and aging
Get PDFAccumulation of senescent cells over time contributes to aging and age-related diseases. However, what drives senescence in vivo is not clear. Here we used a genetic approach to determine if spontaneous nuclear DNA damage is sufficient to initiate senescence in mammals. Ercc1-/Δ mice with reduced expression of ERCC1-XPF endonuclease have impaired capacity to repair the nuclear genome. Ercc1-/Δ mice accumulated spontaneous, oxidative DNA damage more rapidly than wild-type (WT) mice. As a consequence, senescent cells accumulated more rapidly in Ercc1-/Δ mice compared to repair-competent animals. However, the levels of DNA damage and senescent cells in Ercc1-/Δ mice never exceeded that observed in old WT mice. Surprisingly, levels of reactive oxygen species (ROS) were increased in tissues of Ercc1-/Δ mice to an extent identical to naturally-aged WT mice. Increased enzymatic production of ROS and decreased antioxidants contributed to the elevation in oxidative stress in both Ercc1-/Δ and aged WT mice. Chronic treatment of Ercc1-/Δ mice with the mitochondrial-targeted radical scavenger XJB-5–131 attenuated oxidative DNA damage, senescence and age-related pathology. Our findings indicate that nuclear genotoxic stress arises, at least in part, due to mitochondrial-derived ROS, and this spontaneous DNA damage is sufficient to drive increased levels of ROS, cellular senescence, and the consequent age-related physiological decline
Molekularne podłoże chorób spowodowanych mutacjami w genach kodujących podjednostki syntazy ATP
Get PDFSyntaza ATP jest ostatnim enzymem systemu OXPHOS, odpowiedzialnym za syntezę ATP. Mutacje zarówno w genach jądrowych jak i mitochondrialnych, kodujących podjednostki enzymu (17 białek), prowadzą do chorób neurodegeneracyjnych. Dwie podjednostki tego enzymu, 8 (ATP8, inna nazwa A6L) i a (ATP6), kodowane są w genomie mitochondrialnym przez geny MT-ATP8 i MT-ATP6. 17 mutacji związanych z chorobami zidentyfikowano w pięciu genach jądrowych kodujących podjednostki enzymu. 58 mutacji zostało opisanych w genach MT-ATP8 i MT-ATP6, 36 z nich zostało zdeponowanych w bazie danych MITOMAP. Dla większości z nich zarówno patogenny charakter jak i mechanizm choroby nie są znane. W tej pracy podsumowujemy aktualną wiedzę na temat molekularnych podstaw chorób spowodowanych dysfunkcjami syntazy ATP. Opisujemy mutacje w genach kodujących podjednostki enzymu oraz dane biochemiczne uzyskane w badaniach komórek pacjentów, modeli komórkowych i drożdżowych, a ponadto badania wykorzystujące drożdże mające na celu selekcję leków i poznanie ich mechanizmu działania. Mutacje w podjednostkach 8 i a wprowadziliśmy do ostatnio opublikowanej struktury domeny błonowej enzymu i dyskutujemy ich strukturalne i funkcjonalne konsekwencje
Nutrient abundance and variability from soils in the coast of king George Island
Get PDFThe goal of the study was to assess the levels of plant available nutrients in the soils of the Antarctic oasis of Point Thomas in the vicinity of Polish Antarctic Station H. Arctowski. Antarctic soils are undergoing transformations in the era of climatic changes and it is important to quantify changes in soil properties and determine the relationships between soil properties and ecological gradient. Total C and N were determined using CN analyser, mineral forms of nitrogen were determined colorimetrically, plant available P and K was analysed with Egner-Riehm method, Mg with Schachtschabel method and Fe, Mn, Cu, Zn were determined in 1M KCl using AAS (Atomic Absorption Spectrometry) method. The amounts of analysed compounds were dependent on organic matter, which was influenced by plant succession, and in some sites by the activity of seabirds. Most of organic matter was accumulated in the vicinity of penguin colony. All studied soils were abundant in plant available forms of studied macro- and micronutrients. In addition to translocation of biogens (mainly N and P) from the sea to the land by piscivorous birds, a dispersion of biogens on the entire ice-free area occurs. It is related to the occasional appearance of scua as well as the eolian topsoil dust input
Oxidative stress triggers aggregation of GFP-tagged Hsp31p, the budding yeast environmental stress response chaperone, and glyoxalase III
Get PDFThe Saccharomyces cerevisiae Hsp31p protein belongs to the ubiquitous DJ-1/ThiJ/PfpI family. The most prominent member of this family is human DJ-1; defects of this protein are associated with Parkinson's disease pathogenesis. Numerous recent findings reported by our group and others have revealed the importance of Hsp31p for survival in the post-diauxic phase of cell growth and under diverse environmental stresses. Hsp31p was shown to possess glutathione-independent glyoxalase III activity and to function as a protein chaperone, suggesting that it has multiple cellular roles. Our previous work also revealed that HSP31 gene expression was controlled by multiple stress-related transcription factors, which mediated HSP31 promoter responses to oxidative, osmotic, and thermal stresses, toxic products of glycolysis, and the diauxic shift. Nevertheless, the exact role of Hsp31p within budding yeast cells remains elusive. Here, we aimed to obtain insights into the function of Hsp31p based on its intracellular localization. We have demonstrated that the Hsp31p-GFP fusion protein is localized to the cytosol under most environmental conditions and that it becomes particulate in response to oxidative stress. However, the particles do not colocalize with other granular subcellular structures present in budding yeast cells. The observed particulate localization does not seem to be important for Hsp31p functionality. Instead, it is likely the result of oxidative damage, as the particle abundance increases when Hsp31p is nonfunctional, when the cellular oxidative stress response is affected, or when cellular maintenance systems that optimize the state of the proteome are compromised
Genomic and Functional Characterization of Environmental Strains of SDS-Degrading Pseudomonas spp., Providing a Source of New Sulfatases
Get PDFBiochemical, physiological and genomic comparisons of two Pseudomonas strains, assigned previously to the Pseudomonas jessenii subgroup, which are efficient SDS-degraders were carried out. A GO enrichment analysis showed that the genomes of SDS-degraders encode more genes connected with bacterial cell wall biosynthesis and alkanesulfonate monooxygenase activity than their closest relatives from the P. jessenii subgroup. A transcriptomic analysis of the most promising strain exposed to detergent suggests that although SDS can be later utilized as a carbon source, in early stages it influences cell envelope integrity, causing a global stress response followed by cell wall modification and induction of repair mechanisms. Genomes of the analyzed strains from P. jessenii group encode multiple putative sulfatases and their enzymatic activity was experimentally verified, which led to the identification of three novel enzymes exhibiting activity toward SDS. Two of the novel alkylsulfatases showed their highest activity at pH 8.0 and the temperature of 60∘C or 70∘C. One of the enzymes retained its activity even after 1 h of incubation at 60∘C. Ions like K+ and Mg2+ enhanced enzymatic activity of both proteins, whereas Cu2+ or EDTA had inhibitory effects
Jakość i proces starzenia się chlebów z razowych mąk pszennych: z pszenicy zwyczajnej i orkisz oraz z żyta. Quality and Aging of Bread from Wholemeal Common Wheat and Spelt Flours, and from Wholemeal Rye Flour
Get PDFCelem pracy była ocena jakości chlebów z razowej mąki pszennej z pszenicy zwyczajnej i orkiszowej oraz z żyta, uzyskanych na zakwasie spontanicznym z mąki razowej z danego zboża oraz określenie procesu starzenia się tego pieczywa w trakcie przechowywania. W piekarni "Vini" sporządzono z wymienionych trzech mąk razowych zakwasy spontaniczne i dodano je w odpowiedniej proporcji do sporządzenia ciasta. Z 600-gramowych kęsów ciasta wypieczono chleby i po ochłodzeniu oznaczono ich masę, zmierzono objętość, wyliczono stratę wypiekową całkowitą oraz wykonano ocenę organoleptyczną. We wszystkich chlebach oznaczono zawartość: wody, białka ogółem, błonnika pokarmowego (frakcji rozpuszczalnej i nierozpuszczalnej), popiołu (wybranych makro- i mikroelementów), tłuszczu surowego, wybranych mikotoksyn, fosforanów mio-inozytolu, substancji kształtujących smak i zapach oraz akryloamidu. Wykonano również pomiary profilu tekstury miękiszu w dniu wypieku oraz podczas 7-dobowego przechowywania. Oznaczono liczbę tlenowych bakterii amylolitycznych (OLBA), liczbę tlenowych przetrwalnikujących bakterii amylolitycznych (OLBAP), liczbę drożdży i pleśni (OLG) w 1 g pieczywa oraz trwałość termostatową pieczywa po 1., 2., 5. i 7. dobie przechowywania. Największą objętością wyróżniały się chleby z mąki z pszenicy zwyczajnej graham i one też uzyskały najlepszą akceptację konsumentów w ocenie organoleptycznej, zwłaszcza za smak i zapach. Chleby żytnie i z mąki z pszenicy orkisz cechowały się podobną objętością bochenków, przy czym chleby żytnie w większym stopniu niż orkiszowe były akceptowane przez konsumentów. W chlebach z mąki pszennej, zarówno graham, jak i orkiszowej oznaczono zbliżony stosunek zawartości kwasu mlekowego do octowego - średnio 78 : 22, natomiast w chlebie żytnim udział kwasu mlekowego był mniejszy, octowego - większy niż w pieczywie pszennym, a stosunek zawartości kwasu mlekowego do octowego wynosił średnio 68 : 32. W chlebie razowym żytnim oznaczono największą zawartość glukozy. W chlebach razowych pszennych, zarówno orkiszowych, jak i graham, w odróżnieniu od chlebów żytnich, oznaczono zarówno niższe fosforany mio-inozytolu (IP3 i IP2), jak i wyższe fosforany tego związku - IP5 i IP4. W razowych chlebach orkiszowych nie oznaczono nawet śladowych zawartości akryloamidu, a w pozostałych chlebach ilości tego związku były śladowe. Badane chleby wykazały dużą trwałość mikrobiologiczną. W dniu wypieku największą wilgotnością miękiszu odznaczały się chleby żytnie (ok. 50 %), natomiast średnia wilgotność miękiszu chlebów pszennych (orkiszowych i graham) wynosiła ok. 47,5 %. Po 7 dobach przechowywania wilgotność miękiszu wszystkich chlebów zmniejszyła się w bardzo małym stopniu - o 0,5 ÷ 1 p.p., mimo to zaobserwowano postępujący wzrost jego twardości podczas przechowywania, najmniejszy w chlebach żytnich. (abstrakt oryginalny)
The objective of the research study was to assess the quality of bread baked from wholemeal common wheat and spelt wheat wholemeal flours, and from a rye wholemeal flour using a spontaneous sourdough based on the respective wholemeal flour derived from a given cereal, and to determine the aging process of this bread during storage. In a conventional bakery, spontaneous sourdough starters were made from the above named three types of flour and added to the dough in an appropriate proportion. The 600 g pieces of the dough were baked and, after cooling, their weight was determined, their volume was measured, a baking loss was calculated, and an organoleptic assessment was performed. In all the bread loaves, there were determined the contents of: water, total protein, dietary fibre (soluble and insoluble fractions), ash (of the selected macro- and microelements), raw fat, some selected micotoxins, myoinositol phospates, substances that give bread its taste and aroma, and acrylamid. Also, the texture profile of bread crumb was measured on the day of baking and during a 7 day period of storage. Moreover, in 1 g of bread, the count of aerobic amylolytic bacteria (OLBA) was determined as were the counts of sporeforming aerobic amylolytic bacteria (OLBAP), yeasts and moulds (OLG); the thermostatic stability of bread was determined after the 1st, 2nd, 5th, and 7th day of storage. Bread baked from the common wheat Graham flour was characterized by the highest volume and the samples of this bread received, especially for its smell and taste, the highest acceptance of the consumers, who assessed them organoleptically. The rye and spelt bread loaves were characterized by a comparable loaf volume; however, the rye bread was accepted higher by the consumers than the spelt bread. In the bread made from both the common wheat and spelt wheat flour, a similar ratio was determined of lactic to acetic acid (68/32, on average). The highest level of glucose was measured in the rye bread. In contrast to the rye bread, in the bread produced from common and spelt wholemeal flours, there were determined lower contents of myo-inositol phosphates (IP3 and IP2) and higher contents of phosphates of that compound (IP5 and IP4). In the bread from spelt wholemeal flour, even trace contents of acrylamide were not found, and in the other bread loaves, trace amounts of this compound were determined. The bread analysed had a high microbiological stability. On the day of baking, the highest moisture content was reported in the rye bread loaves (approx. 50 %) while the average content of moisture was 47.5 % in the crumb of wheat bread (from common Graham and spelt wheat flour). After 7 days of storage, the moisture content in all the bread loaves decreased to a very low degree: 0.5 to 1 p.p., although their crumbs progressively hardened during storage; the rye bread crumb hardened the slowest. (original abstract
Experimental Investigations of Interactions between Sand Wave Movements, Flow Structure, and Individual Aquatic Plants in Natural Rivers: A Case Study of Potamogeton Pectinatus L.
Get PDFFunction of TFIIIC, RNA polymerase III initiation factor, in activation and repression of tRNA gene transcription
Get PDFTranscription of transfer RNA genes by RNA polymerase III (Pol III) is controlled by general factors, TFIIIB and TFIIIC, and a negative regulator, Maf1. Here we report the interplay between TFIIIC and Maf1 in controlling Pol III activity upon the physiological switch of yeast from fermentation to respiration. TFIIIC directly competes with Pol III for chromatin occupancy as demonstrated by inversely correlated tDNA binding. The association of TFIIIC with tDNA was stronger under unfavorable respiratory conditions and in the presence of Maf1. Induction of tDNA transcription by glucose-activated protein kinase A (PKA) was correlated with the down-regulation of TFIIIC occupancy on tDNA. The conditions that activate the PKA signaling pathway promoted the binding of TFIIIB subunits, Brf1 and Bdp1, with tDNA, but decreased their interaction with TFIIIC. Association of Brf1 and Bdp1 with TFIIIC was much stronger under repressive conditions, potentially restricting TFIIIB recruitment to tDNA and preventing Pol III recruitment. Altogether, we propose a model in which, depending on growth conditions, TFIIIC promotes activation or repression of tDNA transcription
ERAP1 and HLA-C*06 are strongly associated with the risk of psoriasis in the population of northern Poland
Get PDFIntroduction: HLA-C*06 is a major psoriasis genetic risk marker. Recent reports have been focused on the role of
different polymorphisms within genes involved in the functioning of the epidermal barrier and antigen processing
in the pathogenesis of psoriasis. Data on the association between genetic variants of LCE3B_LCE3C, CSTA, ERAP1,
ZAP70 and this dermatosis in the population from Eastern Europe are lacking.
Aim: To compare the association between known genetic risk markers and psoriasis in a cohort of northern Polish
patients with psoriasis and healthy controls.
Material and methods: Based on previous studies’ results, five susceptibility loci: HLA-C, LCE3C_LCE3B, ERAP1,
ZAP70 and CSTA were selected for genotyping in 148 patients with chronic plaque psoriasis and 146 healthy controls.
Each patient with this disease was clinically assessed with the Psoriasis Area and Severity Index.
Results: The study population showed a significant association of psoriasis and a single nucleotide polymorphism in the ERAP1 – rs26653 (p = 3.11 × 10–5) and HLA-C*06 allele (p = 1.02 × 10–11) when compared with the control group.
The presence of HLA-C*06 or rs26653 G allele significantly increased the risk of psoriasis by 2.4 times or twice,
respectively. Carrying rs26653 C allele considerably decreased the risk of psoriasis by 1.5 times.
Conclusions: In the context of pathogenesis of psoriasis, our findings might give the evidence on disturbances in
the proteolytic processing of N-terminal fragments of antigens presented via major histocompatibility complex
class I to T cells