Eml 1605 amplifier research
Albert, Samuel W. Journal of Spacecraft and Rockets. ISSN Ahmed, M. Physical Review Fluids, 6 8.
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- Genetic and Biochemical Alterations in Non-Small Cell Lung Cancer
- The new kid on the block
- Crosstalk between hydroxytyrosol, a major olive oil phenol, and HIF-1 in MCF-7 breast cancer cells
- Items where Research Group Name is "GALCIT"
- Index of /2-SCHEMATICS/LUNDAHL-TRANSFORMERS/SE-AMPLIFIERS
- Cryo-EM structure of the lysosomal chloride-proton exchanger CLC-7 in complex with OSTM1
Genetic and Biochemical Alterations in Non-Small Cell Lung Cancer
The chloride-proton exchanger CLC-7 plays critical roles in lysosomal homeostasis and bone regeneration and its mutation can lead to osteopetrosis, lysosomal storage disease and neurological disorders. Here, we present electron cryomicroscopy structures of CLC-7 in occluded states by itself and in complex with OSTM1, determined at resolutions up to 2.
In the complex, the luminal surface of CLC-7 is entirely covered by a dimer of the heavily glycosylated and disulfide-bonded OSTM1, which serves to protect CLC-7 from the degradative environment of the lysosomal lumen. OSTM1 binding does not induce large-scale rearrangements of CLC-7, but does have minor effects on the conformation of the ion-conduction pathway, potentially contributing to its regulatory role.
Inside the cells of mammals, acidic compartments called lysosomes are responsible for breaking down large molecules and worn-out cells parts so their components can be used again. Similar to lysosomes, specialized cells called osteoclasts require an acidic environment to degrade tissues in the bone. Both osteoclasts and lysosomes rely on a two-component protein complex to help them digest molecules.
Mutations in the genes for both proteins are directly linked to human diseases including neurodegeneration and osteopetrosis — a disease characterized by dense and brittle bones.
For the main protein in this complex, called CLC-7, to remain stable and perform its roles, it requires an accessory subunit known as OSTM1. CLC-7 is a transporter that funnels electrically charged particles into and out of the lysosome, which helps to maintain the environment inside the lysosome compartment.
The analysis revealed that OSTM1 covers almost the entire inside surface of CLC-7, protecting it from the acidic environment inside the lysosome and contributing to its stability.
Schrecker et al. Dysfunction of CLC-7 is associated with dysregulation of ion and pH homoeostasis of the lysosome and the resorption lacuna Graves et al. In particular, osteopetrosis, a disease characterized by dense and brittle bones, is the most common disease associated with CLC-7 mutation, with more than 50 distinct pathogenic mutations identified to date Chalhoub et al.
Within the Cl - -conduction pathway, the gating glutamate Glu gate that is conserved in CLC transporters is proposed to oscillate between at least four different conformations Chavan et al.
The movement and changes in the protonation state of Glu gate are coupled to the binding and release of Cl - ions in the highly conserved external and central binding sites Picollo et al.
OSTM1 is predicted to be a glycosylated, single-pass transmembrane protein and mutations in OSTM1, like mutations in CLC-7, can lead to osteopetrosis and neurodegeneration in humans and mice Chalhoub et al. Following an evaluation of multiple CLC-7 orthologues, we decided to focus our structural studies on the chicken and human CLC-7 proteins based on their expression levels and their biochemical stabilities.
Vitrified human CLC-7 transporters displayed a strongly preferred orientation that was confirmed by two-dimensional classification Figure 1—figure supplement 1. Because of the very limited views of the transporter, we were not able to reconstruct a three-dimensional density map of human CLC In contrast, two-dimensional classification of ggCLC-7 revealed a wide range of views and was suitable for three-dimensional structure determination Figure 1—figure supplement 2.
Three-dimensional classification of the imaged ggCLC-7 transporters identified a single class that displayed both well-ordered transmembrane and cytosolic domains. Reconstruction of these particle images with twofold symmetry imposed yielded a structure of dimeric ggCLC-7 at a resolution of 2. The final refined model, which lacks the disordered N- and C-termini, fits well into the density with good geometry Figure 1B and Figure 1—figure supplement 2 , Figure 1—figure supplement 3 and Table 1.
Modeled non-protein densities are colored orange and unmodeled non-protein densities are colored grey in A. D Dimer interface with interacting residues colored in wheat. The transmembrane domain of ggCLC-7 adopts the canonical CLC architecture with each protomer possessing discrete ion permeation pathways that extend from the cytosol to the lysosomal lumen Figure 2A. Structural and functional analysis of CLC transporters and channels have defined the Cl - -conduction pathway and its three conserved Cl - -binding sites Accardi et al.
In the present conformation of ggCLC-7, constrictions too narrow to accommodate Cl - ions exist on both ends of the Cl - -conduction pathway Figure 2B,C. On the cytosolic side of the pathway between the central and internal Cl - -binding sites, the side chains of Ser, Tyr and Tyr form a constriction with a minimum radius of 0. The luminal side of the Cl - -conduction pathway contains two additional constrictions Figure 2C.
The first constriction, which has a minimum radius of 0. The second constriction 1. Together the three constrictions yield an occluded state for the transporter, sealing off the external and central Cl - -binding sites from the cytosol and the lysosomal lumen. B The cytosolic constriction of the Cl - -conduction pathway formed by Ser, Tyr and Tyr narrows the pathway to a minimum radius of 0. D Cl - -binding sites shown as green spheres in the ggCLC-7 ion conduction pathway.
Conserved residues are shown in sticks. E Ordered water molecules shown as red spheres are resolved in the hydrophobic gap between Glu gate and Glu in and in the solvent-filled cavity in which Glu in resides. The access from the Cl - pathway is lined by Gly, Phe and Phe The pathway is separated from the cytosol by a constriction formed by Ile, Phe and Met The most dynamic residue in the ion transport pathways of CLC transporters is Glu gate , whose conformation changes during the transport cycle.
A non-protein density was resolved between Glu gate and Glu that we assigned as a water molecule. This water may help to stabilize the conformations of Glu gate and Glu, which may both be protonated at pH 8. Within the Cl - -conduction pathway, non-protein densities that we attributed to Cl - ions were resolved at the external, central and internal Cl - -binding sites Figure 2D.
The relative intensities of the three Cl - -binding sites are consistent with structural and biochemical studies performed with E. This bifurcation occurs near the central Cl - -binding site and is proposed to extend through a hydrophobic gap to the conserved Glu in Chavan et al. Within the loosely packed hydrophobic gap between Glu gate and Glu in , several non-protein densities were resolved that we have tentatively modeled as water molecules Figure 2F.
Water molecules have previously been detected within the hydrophobic gap in structures and in molecular dynamics simulations of CLC transporters and have been proposed to serve as a proton-conducting water-wire Chavan et al.
However, the pathway is not continuous with the cytosol as the hydrophobic gap is sealed near Glu in by a 1. It is possible that a similar conformational change may occur during the transport cycle of ggCLC-7 to open the constrictions and allow protons to pass through the hydrophobic gap.
The extended segment is positioned at the center of the three-way interface between the transmembrane domain, CBS1 and CBS2. Because of its central position, the N-terminal domain is a major contributor to the tertiary and quaternary structure of ggCLC Indeed, the N-terminal domain forms a larger interface with the transmembrane domain than either of the CBS domains.
Side chains that interact with ATP are shown as sticks. Immediately adjacent to the N-terminal domain in a groove between the two CBS domains is a large density that cannot be attributed to the protein Figure 3C. Notably, no nucleotides were added during the hour purification of ggCLC-7 so any ATP present must have been co-purified with the transporter.
The adenine base also forms polar interactions with the side-chain oxygen and backbone nitrogen of Thr and the backbone nitrogen of Gly that contribute to the specificity for adenine nucleotides Meyer et al.
The ribose sugar forms polar interactions with side chains of Ser and Asp The triphosphate group is coordinated by residues from both CBS domains as well as the N-terminal domain. Non-protein densities that likely correspond to either ordered lipids or detergents were resolved around the periphery of the transmembrane domain of ggCLC-7 Figures 1A and 4A,B. Because it is difficult to distinguish lipids from detergents based on cryo-EM density maps alone, we were able to assign only one of the densities.
The well-resolved head group allowed us to model the density as a phosphoinositolphosphate PI3P , which is a low-abundance constituent of lysosomal membranes Figure 4A. The PI3P molecule is located at the interface between the transmembrane domain and the cytosolic domain and interacts with residues from both domains. The head group also interacts with Lys, Arg and Arg, which coordinate the phosphate group at the 3 position of inositol ring, and with Val, Leu, Val, Ala, Ser, Thr and Lys A PI3P molecule shown as sticks.
Residues that interact with PI3P head group are shown as sticks. Together, these data suggest that the PI-binding site may be a conserved feature among a subset of CLC transporters.
Due to a low abundance and a preferred orientation of free CLC-7 particles, structural reconstitution of the CLC-7 homodimer was not possible. Reconstruction of these particle images with two-fold symmetry imposed yielded a structure of CLC-7 in complex with OSTM1 at a resolution of 2. We therefore applied masks and performed local refinements, which yielded separate density maps at resolutions between 2. Despite the preferred orientation of the raw data set, the focus refined reconstructions determined with the selected particles display only minimal anisotropy and, following merging into a single composite map, were suitable for model building and coordinate refinement Figure 5B , Figure 5—figure supplement 1 , Figure 5—figure supplement 3 and Table 1.
The luminal domains of OSTM1 form a dimeric cap-like structure that covers the luminal surface of CLC-7 while the transmembrane helices pack against the periphery of the CLC-7 transmembrane domain.
OSTM1 is colored yellow. Connecting both within and between the helical bundles are five disulfide bonds that constrain the organization of the luminal domain. In the first bundle, a disulfide bond connects helix 1 to the short helix 3.
In the second bundle, disulfide bonds connect helix 6 to helix 5 and to the linker between helix 7 and transmembrane helix 8. Between the two bundles, disulfide bonds connect the linker between helices 4 and 5 to helix 2 of the first bundle and to helix 7 of the second bundle Figure 6A,B.
The core of the dimer interface is formed by an antiparallel packing of helices 1 and 4 with helices 3 and 7 and several of the inter-helical linkers also making substantial contributions. While most of the interactions that stabilize the OSTM1 dimer interface are hydrophobic including the entirety of the helix 1-helix 1 and helix 3-helix 3 interactions, several polar interactions are also present including an ionic interaction between Arg and Asp Figure 6D.
Disulfide bonds are shown as pink sticks and glycosylated asparagine residues are shown as sticks. C hsOSTM1 dimer interface. Residues that mediate inter-protomer interactions are colored in wheat. Protomer A is colored yellow and protomer B is colored grey. At the periphery of the luminal domain, non-protein densities were resolved extending from seven exposed asparagine residues 93, , , , , and on OSTM1 Figure 6A. As previous computational analysis had identified these residues as consensus sites for N-linked glycosylation Lange et al.
The quality and interpretability of the carbohydrate densities varied between the seven sites, allowing us to model chains of different length. For example, density for a single N-linked N-acetyl-glucosamine group was resolved for Asn93 and Asn, while a branched five-sugar carbohydrate moiety was resolved for Asn Figure 5—figure supplement 3.
While only minimal carbohydrate moieties can be added to N-linked glycosylation sites in the HEKS GnTI - cell line used for protein expression due to a mutation in N-acetyl-glucosaminyltransferase I, in non-glycoslyation-defective mammalian cells these glycosylation sites would be elaborately decorated and likely encase the entire surface of the luminal domain.
Because CLC-7 lacks any N-linked glycosylation sites, the glycosylation shell surrounding the rigid, disulfide-linked core of OSTM1 likely protects the luminal domain of CLC-7 from the harsh degradative environment of the lysosomal lumen. The cytosolic domains and most of the transmembrane domains are essentially identical.
Asp of CLC-7 forms a polar interaction with Tyr of helix 6. Gly and Gly of CLC-7 form a small interface with a portion of the loop between helices 6 and 7 that includes Pro, Gly and His In addition to the direct protein-protein interactions, a non-protein density that may correspond to a cholesterol based on its size and shape was resolved at the interface between the transmembrane domains of CLC-7 and OSTM1 Figure 5—figure supplement 3.
Residues that participate in the interaction are shown as sticks. Interacting side chains are shown as sticks and Cl - ions are shown as spheres.
In both structures, the Cl - -conduction pathways adopt similar occluded states with narrow constrictions present at either end and ions occupying the three binding sites.
Superpositioning reveals that most of the pore-lining residues are positioned similarly in the presence and absence of OSTM1. Inspection of the ggCLC-7 density map revealed no density consistent with the alternative rotamer, indicating that conformation two is the predominant state for Phe Thus, while we modeled Phe as the predominant conformation 1, the data also supports the existence of conformation 2.
The new kid on the block
The availability of compliant actuators is essential for the development of soft robotic systems. A DE consists of a thin elastomer membrane coated with flexible electrodes on both sides. When a high voltage is applied to the electrodes, the membrane undergoes a controllable mechanical deformation. In order to produce a significant actuation stroke, a DE membrane must be coupled with a mechanical biasing system. Commonly used spring-like bias elements, however, are generally made of rigid materials such as steel, and thus they do not meet the compliance requirements of soft robotic applications.
Crosstalk between hydroxytyrosol, a major olive oil phenol, and HIF-1 in MCF-7 breast cancer cells
Jackie L. Johnson, Smitha Pillai, Srikumar P. Despite significant advances in the detection and treatment of lung cancer, it causes the highest number of cancer-related mortality. Recent advances in the detection of genetic alterations in patient samples along with physiologically relevant animal models has yielded a new understanding of the molecular etiology of lung cancer. This has facilitated the development of potent and specific targeted therapies, based on the genetic and biochemical alterations present in the tumor, especially non-small-cell lung cancer NSCLC. How these pathways differ between smokers and non-smokers is also important for clinical treatment strategies and development of targeted therapies. This paper describes these molecular targets in NSCLC, and describes the biological significance of each mutation and their potential to act as a therapeutic target. Lung cancer is the leading cause of cancer-related mortality, annually resulting in more than one million deaths worldwide. In the United States itself, there would have been , new cases of lung cancer diagnosed in , with about , deaths [ 1 ]. Death from cancers of the lung and the respiratory system would exceed the number of deaths from cancers of breast, colon, pancreas, and the prostate combined.
Items where Research Group Name is "GALCIT"
If you can email me a copy of both I would appreciate it. Circuit Description The model is the B Parallel version which provides approx 20W of single ended power with zero feedback The design is unique in that is uses a 1 1 interstage transformer between the driver stage and Interstage Monoblock B The Interstage amplifier is our highest and most extreme expression of Single Ended Amplification reserved only for the true connoisseur audiophile. The amps has tube rectification 6SN7 pre. These specifications at the time of introduction by Western Electric were good for 6 watts of glorious output power.
Index of /2-SCHEMATICS/LUNDAHL-TRANSFORMERS/SE-AMPLIFIERS
Try out PMC Labs and tell us what you think. Learn More. Raloxifene hydrochloride RLX , an antiosteoporotic agent, has been utilized for guarding against breast cancer and recently, for the disease management owing to its estrogen antagonist activity. Nevertheless, RLX exhibits poor bioavailability that could be attributed to reduced water solubility and first pass metabolism. A 4 1 3 1 factorial design was employed for assessing the effect of lipoid: solid lipid ratio and solid lipid type on the emulsomes characteristics. The anticancer potential of the optimized formulation and apoptotic parameters were assessed.
Cryo-EM structure of the lysosomal chloride-proton exchanger CLC-7 in complex with OSTM1
View Full Version : Halgorythme in the house! Dear friends, in this thread I want to share my experience with our new tube amps. You can read how we came to this brand in 2 other threads. A good time to enjoy the last semester with and then say goodbye to my fantastic Burmester amplifier. I have to underline this remains a fantastic piece of kit. After all, I chose it above the McIntosh and Accuphase integrateds at my dealer's in These are your amps, he wrote.
Switch Editions? Channel: High Fidelity. Mark channel Not-Safe-For-Work?
Really there is none, or at least nothing you can see. Then they got worse I probably won't need to state this, but I'm pretty much a novice at all this. I had them in my amplifiers for several weeks until they failed. If someone wants to hear something more, they can ask the manufacturer to use also the JJ B Boxed individually. Transmission: constant mesh.
Karapiperis, K. Computer Methods in Applied Mechanics and Engineering, ISSN Pandolfi, A. Scripta Materialia, Energy, Journal of Fluid Mechanics,
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