Cryo-EM structures of complex I from mouse heart mitochondria in two biochemically defined states.

Complex I (NADH:ubiquinone oxidoreductase) uses the reducing potential of NADH to drive protons across the energy-transducing inner membrane and power oxidative phosphorylation in mammalian mitochondria. Recent cryo-EM analyses have produced near-complete models of all 45 subunits in the bovine, ovine and porcine complexes and have identified two states relevant to complex I in ischemia-reperfusion injury. Here, we describe the 3.3-Å structure of complex I from mouse heart mitochondria, a biomedically relevant model system, in the 'active' state. We reveal a nucleotide bound in subunit NDUFA10, a nucleoside kinase homolog, and define mechanistically critical elements in the mammalian enzyme. By comparisons with a 3.9-Å structure of the 'deactive' state and with known bacterial structures, we identify differences in helical geometry in the membrane domain that occur upon activation or that alter the positions of catalytically important charged residues. Our results demonstrate the capability of cryo-EM analyses to challenge and develop mechanistic models for mammalian complex I

Effect of diet and other factors on serum adiponectin concentrations in patients with type 2 diabetes

Background. Adiponectin is a protein specific to visceral adipose tissue where its concentrations are reduced in type 2 diabetes and obesity. Many factors also determine serum levels of adiponectin such as gender, BMI, as well as diet. Objective. To compare the effects of consuming certain key foodstuff products on serum adiponectin concentrations between diabetic patients and suitable controls. Material and methods. A survey and laboratory testing was performed on 72 patients of whom (n = 21) were diabetics, whilst the control group, (n = 51) non-diabetics. Eating habits were assessed and serum adiponectin was measured in all cases. Results. Diabetic patients had significantly lower adiponectin levels compared to the control group; respectively (23.5±21.1 μg/ml vs. 36.5±21.1 μg/ml; p=0.02). Furthermore, women had higher concentration than men; respectively (41.3 μg/ml± 20.1 μg/ml vs. 22.0 μg/ml± 14.8 μg/ml; p=0.000). A high consumption of foodstuffs such as vegetables, vegetable oils, coffee and tea positively correlated with adiponectin concentration in serum, whilst a negative correlation was seen with consumptions of mixed bread, fried and baked dishes, alcohol, nuts and seeds. Conclusions. Serum adiponectin levels are related to factors such as gender, (higher in women), BMI, (higher in persons with normal body weight) and whether diabetic, (lower in people with diabetes). Multiple correlations were observed between the consumption of foodstuff product groups and serum adiponectin concentration. It is thereby suggested, that adiponectin could have a significant role to play in the treatment and prevention of diabetes and obesity.Wprowadzenie. Adiponektyna jest białkiem swoistym dla tkanki tłuszczowej wisceralnej. Zmniejszone jej stężenie obserwuje się w cukrzycy typu 2 oraz otyłości. Istnieje wiele czynników determinujących poziom adiponektyny w surowicy krwi tj. płeć, BMI, ale również dieta. Celem pracy była ocena wpływu spożywanych grup produktów na poziom adiponektyny w surowicy krwi osób z cukrzycą oraz grupy kontrolnej. Materiał i metody. Badaniem ankietowym oraz analizą laboratoryjną objęto 72 pacjentów. Grupę badaną (n=21 osób) stanowiły osoby chore na cukrzycę, natomiast grupę kontrolną (n=51 osób) stanowiły osoby bez cukrzycy. Ocenie poddano sposób żywienia oraz zawartość adiponektyny w surowicy krwi pacjentów. Wyniki. Adiponektyna osiągała niższe wartości u osób z cukrzycą w porównaniu do grupy kontrolnej (23,5±21,1 μg/ml vs. 36,5±21,1 μg/ml; p=0,02). Kobiety charakteryzowały się wyższym jej stężeniem w stosunku do mężczyzn (41,3 μg/ml± 20,1 μg/ml vs. 22,0 μg/ml± 14,8 μg/ml; p=0,000). Wysoka częstość spożycia produktów spożywczych takich jak: warzywa, oleje roślinne, kawa i herbata dodatnio korelowała ze stężeniem adiponektyny w surowicy krwi. Natomiast spożywanie pieczywa mieszanego, potraw smażonych i pieczonych, alkoholu, orzechów i pestek było ujemnie skorelowane ze stężeniem adiponektyny w surowicy krwi. Wnioski. Wykazano, że poziom adiponektyny w surowicy krwi zależy od czynników takich jak: płeć (wyższy u kobiet), BMI (wyższy u osób z prawidłową masą ciała) oraz obecności cukrzycy (niższy u osób z cukrzycą). Zaobserwowano wiele korelacji dotyczących częstości spożycia produktów, a stężeniem adiponektyny w surowicy krwi, co też może odgrywać znaczącą rolę w leczeniu oraz profilaktyce cukrzycy oraz otyłości

Synthesis and Bioactivity of RGO/TiO2-Noble Metal Nanocomposite Flakes

abstractEN: This study aims to describe the influence of adding graphene oxide to TiO2-noble metal (Me=Ag, Au or Pd) composite nanoparticles on their bioactivity (formation of RGO/TiO2-Me nanocomposite system). The obtained nanocomposite flakes and reference TiO2-Me nanoparticles were characterized using SEM, HRTEM and XPS spectroscopy, N2 sorption analysis and helium pycnometer. The analysis of the antibacterial properties of synthesized nanocomposites revealed a growth inhibiting effect of TiO2-Ag particles on gram positive bacteria such as: Staphylococcus aureus, Sarcina lutea and Bacillus subtilis. In the case of nanocomposite flakes containing RGO the visible changes in bacteriostatic properties were observed, including unexpected reversal of the antimicrobial activity of silver-containing nanoparticles into the stimulation of growth of applied bacterial strains. The stimulation of growth was not observed for TiO2-Au and Pd nanoparticles deposited on the surface of RGO.score: 15collation: 33-4