Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Ca2+" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-6 z 6
    Tytuł:
    Regulation of Ca2+ release from internal stores in cardiac and skeletal muscles.
    Autorzy:
    Wrzosek, Antoni
    Powiązania:
    https://bibliotekanauki.pl/articles/1044313.pdf
    Data publikacji:
    2000
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    Ca2+-induced Ca2+ release
    calcium channels
    dihydropyridine receptor
    calcium sparks
    excitation-contraction coupling
    ryanodine receptor
    Opis:
    It is widely accepted that Ca2+ is released from the sarcoplasmic reticulum by a specialized type of calcium channel, i.e., ryanodine receptor, by the process of Ca2+-induced Ca2+ release. This process is triggered mainly by dihydropyridine receptors, i.e., L-type (long lasting) calcium channels, directly or indirectly interacting with ryanodine receptor. In addition, multiple endogenous and exogenous compounds were found to modulate the activity of both types of calcium channels, ryanodine and dihydropyridine receptors. These compounds, by changing the Ca2+ transport activity of these channels, are able to influence intracellular Ca2+ homeostasis. As a result not only the overall Ca2+ concentration becomes affected but also spatial distribution of this ion in the cell. In cardiac and skeletal muscles the release of Ca2+ from internal stores is triggered by the same transport proteins, although by their specific isoforms. Concomitantly, heart and skeletal muscle specific regulatory mechanisms are different.
    Źródło:
    Acta Biochimica Polonica; 2000, 47, 3; 705-723
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Ca2+-dependent phosphatidylserine synthesis in immature and mature starfish oocytes.
    Autorzy:
    Dygas, Anna
    Barańska, Jolanta
    Santella, Luigia
    Powiązania:
    https://bibliotekanauki.pl/articles/1043613.pdf
    Data publikacji:
    2003
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    PSS2
    phosphatidylserine synthesis
    nucleus
    Ca2+
    PSS1
    starfish oocyte
    Opis:
    We found that in starfish oocytes two different enzymes, phosphatidylserine synthase-1 (PSS1) and -2 (PSS2), which synthesize phosphatidylserine by a base-exchange reaction, are present. We studied phosphatidylserine synthesis in immature oocytes which still contain the nucleus (germinal vesicles) and in mature cells, in which the re-initiation of the meiotic cycle induced by the hormone 1-methyladenine led to structural changes in the endoplasmic reticulum, to the disappearance of the nuclear envelope and to the intermixing of the nucleoplasm with the cytoplasm. It was found that the levels of PSS1 and PSS2 transcripts were higher in immature and mature oocytes, respectively. The level of the expressed PSS2 protein, higher than that of PSS1, was not influenced by the maturation process, whereas the level of PSS1 protein was higher in immature than in mature oocytes. Serine incorporation into phosphatidylserine was enhanced in immature oocytes. The depletion of calcium stores by thapsigargin resulted in 50% lowering of phosphatidylserine synthesis. We suggest that changes in phosphatidylserine synthesis may be affected by the release of calcium stored in the nuclear envelope and in the endoplasmic reticulum, the membranes that undergo disintegration and fragmentation during meiosis. The reason for the greater synthesis of PS may be the higher level of expression of PSS1 in immature oocytes.
    Źródło:
    Acta Biochimica Polonica; 2003, 50, 2; 377-387
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Plasma membrane Ca2+ -ATPase in excitable and nonexcitable cells.
    Autorzy:
    Żylińska, Ludmiła
    Soszyński, Mirosław
    Powiązania:
    https://bibliotekanauki.pl/articles/1044284.pdf
    Data publikacji:
    2000
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    calcium homeostasis
    brain
    erythrocytes
    plasma membrane Ca2+ -ATPase
    Opis:
    There is a significant number of data confirming that the maintenance of calcium homeostasis in a living cell is a complex, multiregulated process. Calcium efflux from excitable cells (i.e., neurons) occurs through two main systems - an electrochemically driven Na+/Ca2+ exchanger with a low Ca2+ affinity (K0.5 = 10-15 μM), and a plasmalemmal, specific Ca2+-ATPase, with a high Ca2+ affinity (K0.5 < 0.5-1 μM), whereas in nonexcitable cells (i.e., erythrocytes) the calcium pump is the sole system responsible for the extrusion of calcium ions. The plasma membrane Ca2+-ATPase (PMCA) is a ubiquitously expressed protein, and more than 26 transcripts of four PMCA genes are distributed in a tissue specific manner. Differences in the structure and localization of PMCA variants are thought to correlate with specific regulatory properties and may have consequences for proper cellular Ca2+ signaling. The regulatory mechanisms of calcium pump activity have been studied extensively, resulting in a new view of the functioning of this important molecule in the membranes.
    Źródło:
    Acta Biochimica Polonica; 2000, 47, 3; 529-539
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Animal electricity, Ca2+ and muscle contraction. A brief history of muscle research
    Autorzy:
    Martonosi, Anthony
    Powiązania:
    https://bibliotekanauki.pl/articles/1044280.pdf
    Data publikacji:
    2000
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    cardiac and smooth muscles
    skeletal
    Ca2+
    Mg-ATP
    sarcoplasmic reticulum
    contraction-relaxation cycle
    Opis:
    This brief review attempts to summarize some of the major phases of muscle research from Leeuwenhoek's description of sarcomeres in 1674, through Galvani's observation of "animal electricity" in 1791, to the discovery of Ca2+ as the key messenger in the coupling of nerve excitation to muscle contraction. The emerging molecular mechanism of the contraction process is one of the great achievements of biology, reflecting the intimate links between physics, chemistry and the life Sciences in the solution of biological problems.
    Źródło:
    Acta Biochimica Polonica; 2000, 47, 3; 493-516
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Photoreceptor guanylate cyclase variants: cGMP production under control.
    Autorzy:
    Sokal, Izabela
    Alekseev, Andrei
    Palczewski, Krzysztof
    Powiązania:
    https://bibliotekanauki.pl/articles/1043388.pdf
    Data publikacji:
    2003
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    rhodopsin
    photoreceptor cells
    guanylate cyclase
    Ca2+-binding proteins
    guanylate cyclase-activating protein
    retina
    Opis:
    Changes in the Ca2+ concentration are thought to affect many processes, including signal transduction in a vast number of biological systems. However, only in few cases the molecular mechanisms by which Ca2+ mediates its action are as well understood as in phototransduction. In dark-adapted photoreceptor cells, the equilibrium level of cGMP is maintained by two opposing activities, such as phosphodiesterase (PDE) and guanylate cyclase (GC). Upon absorption of photons, rhodopsin-G-protein-mediated activation of PDE leads to a transient decrease in [cGMP] and subsequently to lowering of [Ca2+]. In turn, lower [Ca2+] increases net production of cGMP by stimulation of GC until dark conditions are re-established. This activation of GC is mediated by Ca2+-free forms of Ca2+-binding proteins termed GC-activating proteins (GCAPs). The last decade brought the molecular identification of GCs and GCAPs in the visual system. Recent efforts have been directed toward understanding the properties of GC at the physiological and structural levels. Here, we summarize the recent progress and present a list of topics of ongoing research.
    Źródło:
    Acta Biochimica Polonica; 2003, 50, 4; 1075-1095
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Order-disorder structural transitions in synthetic filaments of fast and slow skeletal muscle myosins under relaxing and activating conditions.
    Autorzy:
    Podlubnaya, Zoya
    Malyshev, Sergey
    Nieznański, Krzysztof
    Stępkowski, Dariusz
    Powiązania:
    https://bibliotekanauki.pl/articles/1044221.pdf
    Data publikacji:
    2000
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    method of slow skeletal muscle myosin preparation.
    Ca2+-induced structural transitions
    myosin filaments
    fast and slow skeletal muscle myosin
    Opis:
    In the previous study (Podlubnaya et al., 1999, J. Struc. Biol. 127, 1-15) Ca2+-induced reversible structural transitions in synthetic filaments of pure fast skeletal and cardiac muscle myosins were observed under rigor conditions (-Ca2+/+ Ca2+). In the present work these studies have been extended to new more order-producing conditions (presence of ATP in the absence of Ca2+) aimed at arresting the relaxed structure in synthetic filaments of both fast and slow skeletal muscle myosin. Filaments were formed from column-purified myosins (rabbit fast skeletal muscle and rabbit slow skeletal semimebranosus proprius muscle). In the presence of 0.1 mM free Ca2+, 3 mM Mg2+ and 2 mM ATP (activating conditions) these filaments had a spread structure with a random arrangement of myosin heads and subfragments 2 protruding from the filament backbone. Such a structure is indistinguishable from the filament structures observed previously for fast skeletal, cardiac (see reference cited above) and smooth (Podlubnaya et al., 1999, J. Muscle Res. Cell Motil. 20, 547-554) muscle myosins in the presence of 0.1 mM free Ca2+. In the absence of Ca2+ and in the presence of ATP (relaxing conditions) the filaments of both studied myosins revealed a compact ordered structure. The fast skeletal muscle myosin filaments exhibited an axial periodicity of about 14.5 nm and which was much more pronounced than under rigor conditions in the absence of Ca2+ (see the first reference cited). The slow skeletal muscle myosin filaments differ slightly in their appearance from those of fast muscle as they exhibit mainly an axial repeat of about 43 nm while the 14.5 nm repeat is visible only in some regions. This may be a result of a slightly different structural properties of slow skeletal muscle myosin. We conclude that, like other filaments of vertebrate myosins, slow skeletal muscle myosin filaments also undergo the Ca2+-induced structural order-disorder transitions. It is very likely that all vertebrate muscle myosins possess such a property.
    Źródło:
    Acta Biochimica Polonica; 2000, 47, 4; 1007-1017
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-6 z 6

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies