Cardiolipin drives cytochrome c proapoptotic and antiapoptotic actions

""\\"Cytochrome c (cytc) is pivotal in mitochondrial respiration and apoptosis. The heme-Fe-atom of native hexacoordinated horse heart cytc (hhcytc) displays a very low reactivity toward ligands and does not exhibit catalytic properties. However, on interaction with cardiolipin (CL), hhcytc changes its tertiary structure disrupting the heme-Fe-Met80 distal bond. The CL-hhcytc complex displays a very low midpoint potential, out of the range required for its physiological role, binds CO and NO with high affinity, facilitates peroxynitrite isomerization to NO(3)(-), and displays peroxidase activity. As a whole, the CL-hhcytc complex could play either proapoptotic effects, catalyzing lipid peroxidation and the subsequent hhcytc release into the cytoplasm, or antiapoptotic actions, such as scavenging peroxynitrite (i.e., protecting the mitochondrion from reactive nitrogen and oxygen species), and binding of CO and NO (i.e., inhibiting lipid peroxidation and hhcytc traslocation). Here, the CL-driven allosteric modulation of hhcytc properties is reviewed, highlighting proapoptotic and antiapoptotic actions. (C) 2011 IUBMB IUBMB Life, 63(3): 160-165, 2011\\""

The key role played by charge in the interaction of cytochrome c with cardiolipin

Cytochrome c undergoes structural variations upon binding of cardiolipin, one of the phospholipids constituting the mitochondrial membrane. Although several mechanisms governing cytochrome c/cardiolipin (cyt c/CL) recognition have been proposed, the interpretation of the process remains, at least in part, unknown. To better define the steps characterizing the cyt c-CL interaction, the role of Lys72 and Lys73, two residues thought to be important in the protein/lipid binding interaction, were recently investigated by mutagenesis. The substitution of the two (positively charged) Lys residues with Asn revealed that such mutations cancel the CL-dependent peroxidase activity of cyt c; furthermore, CL does not interact with the Lys72Asn mutant. In the present paper, we extend our study to the Lys → Arg mutants to investigate the influence exerted by the charge possessed by the residues located at positions 72 and 73 on the cyt c/CL interaction. On the basis of the present work a number of overall conclusions can be drawn: (i) position 72 must be occupied by a positively charged residue to assure cyt c/CL recognition; (ii) the Arg residues located at positions 72 and 73 permit cyt c to react with CL; (iii) the replacement of Lys72 with Arg weakens the second (low-affinity) binding transition; (iv) the Lys73Arg mutation strongly increases the peroxidase activity of the CL-bound protein

إعداد مواد تعليمية لتنمية المهارات اللغوية لطلبة الصفّ الأول المتوسّط: بحث تطويريّ بمدرسة التوحيد المتوسّطة الدينية بنكالان مادورا.

Kegiatan Pembelajaran Bahasa Arab di Madrasah Diniah Tsanawiyah “At tauhid” Bangkalan Madura masih menggunakan buku ajar yang tidak sesuai, adapun kitab yang digunakan hanya memacu pada ketrampilan berbicara saja tidak pada 4 ketrampilan bahasa seperti mendengar, berbicara, membaca, menulis dan didalam kitab tersebut tidak terdapat latihan soal yang dapat memicu kemampuan bahasa arab para santri disana.maka dari itu penulis ingin mendesain bahan ajar yang bagus dan sesuai kurikulum 2013 kementrian agama RI karena kurikulum dapat membantu untuk mentertibkan proses belajar mengajar pada sekolah khususnya dalam pembuatan materi ajar bagi penulis. Penulis menggunakan metode Research and Developmentdengan pendekatan kuantitatif dan kualitatif untuk menganalisa data dan nilai, serta menjelaskan efektifitas penerapan Materi Ajar dalam pembelajaran bahasa arab adapun sampelnya adalah para santri kelas 1 tingkat Tsanawiyah yang berjumlah 15 santriwan/i. adapun teknik pengumpulan data penelitian ini yaitu: Observasi, interview, tes, dan dokumentasi. Dan hasil penelitian ini adalah: 1)Pengembangan bahan ajar yang terdesain memiliki beberapa proses tahap pembuatan agar memiliki karakter sebagai peningkatan kemampuan bahasa. 2)Adapun penerapannya dilihat dari proses pembuatan, langkah – langkah, dan ujicoba. 3)Adanya efektifitas dari materi ajar dibuktokan dengan adanya perubahan dari nilai pretest dan post test berdasarkan atas perbandingan t-hitung dan t-tabel yang menunjukkan t-hitung lebih besar dari pada t-tabel

Growth and glycemic control in children with type 1 diabetes and asymptomatic celiac disease treated with a gluten -free diet for 1 year

To compare growth and glycemic control in children with type 1 diabetes and silent celiac disease treated with a gluten-free diet for 1 year with those of similar age and gender with type 1 diabetes but without celiac disease, 16 type 1 diabetes patients with silent celiac disease were enrolled and each celiac disease-positive case was matched for age, sex, and duration of diabetes with two type 1 diabetes controls with negative serologic markers of celiac disease. All 16 children with positive celiac disease serology had histologic features consistent with celiac disease despite the absence of symptoms. The mean growth and metabolic control values were similar between children with type 1 diabetes and celiac disease and those with type 1 diabetes but without celiac disease. This study seems to suggest that the early diagnosis of celiac disease and initiation of a gluten-free diet may prevent further deterioration in the nutritional status of children with type 1 diabetes and celiac disease and may reduce the prospect of celiac disease complications without any impact on type 1 diabetes control

Purification, inhibitory properties, amino-acid-sequence and identification of the reactive-site of a new serine proteinase- inhibitor from oil-rape (Brassica napus) seed

A new serine proteinase inhibitor, rapeseed trypsin inhibitor (RTI), has been isolated from rapeseed (Brassica napus var. oleifera) seed. The protein inhibits the catalytic activity of bovine beta-trypsin and bovine alpha-chymotrypsin with apparent dissociation constants of 3.0 x 10(-10) M and 4.1 x 10(-7) M, at pH 8.0 and 21 degrees C, respectively. The stoichiometry of both proteinase-inhibitor complexes is 1:1. The amino acid sequence of RTI consists of 60 amino acid residues, corresponding to an M(r) of about 6.7 kDa. The P1-P1' reactive site bond has been tentatively identified at position Arg20-Ile21. RTI shows no similarity to other serine proteinase inhibitors except the low molecular weight mustard trypsin inhibitor (MTI-2). RTI and MTI-2 could be members of a new class of plant serine proteinase inhibitors

Pathophysiologic risk stratification of chronic heart failure: coexisting left atrial and right ventricular damage and the role of pulmonary circulation

Abstract Funding Acknowledgements Type of funding sources: None. Background in heart failure with reduced ejection fraction (HFrEF) the chronic increase of filling pressures progressively involves left atrium (LA), pulmonary circulation (PC) and right ventricle (RV), leading to worse outcome. Purpose we investigated the prognostic impact of either isolate LA impairment, RV dysfunction combined with pulmonary hypertension, or both, in HFrEF, using basic and advanced echocardiography. Methods 106 outpatients with HFrEF were enrolled. Exclusion criteria were primary lung disease, non-sinus rhythm, previous cardiac surgery, poor acoustic window. Clinical examination and basic echocardiography were performed. Speckle tracking analysis was used to measure peak atrial longitudinal strain (PALS) and a new marker of interaction between RV and PC: absolute free wall RV longitudinal strain(fwRVLS)/systolic pulmonary artery pressure(sPAP). Patients were followed for all-cause or cardiovascular death and heart failure (HF) hospitalization. Results of 84 eligible patients [mean age: 60.1 ± 11.5; 82% male, mean left ventricular ejection fraction (LV EF) 28 ± 5%], 48 reached the combined endpoint. Population was divided into 3 groups: Group 1 [PALS≥15 and fwRVLS/sPAP ≤ 0.5]; Group 2 [PALS ≤ 15 and fwRVLS/sPAP ≤ 0.5 or PALS≥15 and fwRVLS/sPAP≥0.5]; Group 3 [PALS ≤ 15 and fwRVLS/sPAP≥0.5]. Mean follow-up was 3.5 ± 0.3years. The increasing severity groups were associated with higher LA volume index (LAVI), New York Heart Association (NYHA) class, mitral regurgitation (MR) and tricuspid regurgitation (TR) grades, lower LV EF, LV global longitudinal strain (GLS), PALS, tricuspid annular plane systolic excursion (TAPSE), sPAP, fwRVLS and global RVLS(p < 0.0001). Reduced PALS and fwRVLS/sPAP were independent predictors of NYHA > 2 at univariate and multivariate analysis adjusted for age, sex, LV EF, and of any events with adjusted Cox models (Table 1). Kaplan-Meier curves showed a clear divergence between the groups for the prediction of the combined endpoint (Fig.1), cardiovascular death and HF hospitalization. Conclusions the combination of LA and RV damage could represent the transition point to end-stage HF, with considerably worse prognosis. Its assessment with PALS and fwRVLS/sPAP could help risk stratification of HFrEF patients in order to provide early treatment. Table 1 Unadjusted hazard ratio [95% CI] Adjusted for GLS hazard ratio [95% CI] Adjusted for GLS, LAVi, TR, RVFAC hazard ratio [95% CI] Group 3 vs 1 10.61 [4.16-27.06], p < 0.0001 10.24 [3.49-30.02], p < 0.0001 9.54 [2.95-30.92], p = 0.0002 Group 3 vs 2 3.90 [1.92-7.93], p = 0.0002 3.82 [1.74-8.36], p = 0.0008 3.78 [1.66-8.61], p = 0.002 Group 2 vs 1 2.72 [1.03-7.20], p = 0.04 2.69 [0.99-7.25], p = 0.05 2.53 [0.84-7.58], p = 0.1 CI, confidence interval; EF, ejection fraction; GLS, global longitudinal strain;LAVI, left atrial volume index; MR, mitral regurgitation, TR, tricuspid regurgitation Abstract Figure. Fig.

The rise and fall of the high-energy afterglow emission of GRB 180720B

The Gamma Ray Burst (GRB) 180720B is one of the brightest events detected by the Fermi satellite and the first GRB detected by the H.E.S.S. telescope above 100 GeV. We analyse the Fermi (GBM and LAT) and Swift (XRT and BAT) data and describe the evolution of the burst spectral energy distribution in the 0.5 keV - 10 GeV energy range over the first 500 seconds of emission. We reveal a smooth transition from the prompt phase, dominated by synchrotron emission in a moderately fast cooling regime, to the afterglow phase whose emission has been observed from the radio to the GeV energy range. The LAT (0.1 - 100 GeV) light curve initially rises ($F_{\rm LAT}\propto t^{2.4}$), peaks at $\sim$78 s, and falls steeply ($F_{\rm LAT}\propto t^{-2.2}$) afterwards. The peak, which we interpret as the onset of the fireball deceleration, allows us to estimate the bulk Lorentz factor $\Gamma_{0}\sim 150 \ (300)$ under the assumption of a wind-like (homogeneous) circum-burst medium density. We derive a flux upper limit in the LAT energy range at the time of H.E.S.S. detection, but this does not allow us to unveil the nature of the high energy component observed by H.E.S.S. We fit the prompt spectrum with a physical model of synchrotron emission from a non-thermal population of electrons. The 0 - 35 s spectrum after its $E F(E)$ peak (at 1 - 2 MeV) is a steep power law extending to hundreds of MeV. We derive a steep slope of the injected electron energy distribution $N(\gamma)\propto \gamma^{-5}$. Our fit parameters point towards a very low magnetic field ($B'\sim 1$ G) in the emission region.Comment: 10 pages, 6 figures, submitted to A&

BIOGENIC AMINE CONTENT IN "PECORINO DEL PARCO DI MIGLIARINO - SAN ROSSORE"

Biogenic amines (BAs) can be naturally present in several foods. They are mainly produced in large amounts by amino acid decarboxylases activity of bacteria. The BAs content has been associated to the quality of raw material and to fermentation or spoilage processes. The aim of the present study was to asses the content of BAs (single and total value) in the core and in the external part of a Tuscan traditional pecorino cheese. Sixteen "Pecorino del Parco di Migliarino-San Rossore" cheeses belonging to same batch were tested during ripening time, up to 5 months. BAs content was analyzed by an HPLC-UV method. The BAs content was significantly higher in the core than in the external part. Tyramine was the amine most frequently detected and largely quantized, followed by putrescine, histamine and cadaverine

Characterization of a globin-coupled oxygen sensor with a gene-regulating function

Globin-coupled sensors (GCSs) are multiple-domain transducers, consisting of a regulatory globin-like heme-binding domain and a linked transducer domain(s). GCSs have been described in both Archaea and bacteria. They are generally assumed to bind O2 (and perhaps other gaseous ligands) and to transmit a conformational change signal through the transducer domain in response to fluctuating O2 levels. In this study, the heme-binding domain, AvGReg178, and the full protein, AvGReg of the Azotobacter vinelandii GCS, were cloned, expressed, and purified. After purification, the heme iron of AvGReg178 was found to bind O2. This form was stable over many hours. In contrast, the predominant presence of a bis-histidine coordinate heme in ferric AvGReg was revealed. Differences in the heme pocket structure were also observed for the deoxygenated ferrous state of these proteins. The spectra showed that the deoxygenated ferrous derivatives of AvGReg178 and AvGReg are characterized by a penta-coordinate and hexa-coordinate heme iron, respectively. O2 binding isotherms indicate that AvGReg178 and AvGReg show a high affinity for O2 with P50 values at 20 °C of 0.04 and 0.15 torr, respectively. Kinetics of CO binding indicate that AvGReg178 carbonylation conforms to a monophasic process, comparable with that of myoglobin, whereas AvGReg carbonylation conforms to a three-phasic reaction, as observed for several proteins with bis-histidine heme iron coordination. Besides sensing ligands, in vitro data suggest that AvGReg(178) may have a role in O2-mediated NO-detoxification, yielding metAvGReg(178) and nitrate. © 2007 by The American Society for Biochemistry and Molecular Biology, Inc