Informacja

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

Wyszukujesz frazę "Conjugate" wg kryterium: Temat


Wyświetlanie 1-6 z 6
Tytuł:
Synthesis and biological activity of raltitrexed-carrier conjugates
Autorzy:
Jagiello, Monika
Kanska, Urszula
Nevozhay, Dmitry
Boratynski, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/1040427.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
raltitrexed
tomudex
carrier
conjugate
thymidylate synthase
Opis:
Drugs used in chemotherapy give undesirable side effects, e.g., cardiotoxicity, leucopenia, hair loss and others. Covalent binding of a drug with a carrier may change its biodistribution, elimination and/or rate of transformation in the organism. The aim of this work was to synthesize conjugates of anticancer drug - raltitrexed (RTX) with lysozyme, bovine serum albumin (BSA), and dextran T40 and to investigate their cytotoxicity and influence on the cell cycle in comparison with the free drug. Before conjugation RTX was transformed into anhydride by treatment with dicyclohexylcarbodiimide in dimethylformamide. Activated RTX was added into aqueous solution of carriers at different pH (from 8.5 to 10.5) for 3 to 15 min. The reaction was stopped by reducing the pH to 7.0. Maximum yield of the reaction was obtained at pH 10 for BSA as well as for dextran. The highest level of substitution was obtained after 5 min of the reaction. In in vitro experiments on three cell lines: SW707, LoVo and A549, all conjugates tested had up to a few hundred times higher IC50 than the free drug. Interestingly, it was noticed that the conjugates based on dextran and albumin were more cytotoxic than the free drug in the highest concentrations tested (1000 and 10000 ng/ml). The influence of RTX and the conjugates on SW707 cell cycle was studied. RTX blocked the cell cycle mostly in the G0-G1 and S phase and increased the percentage of apoptotic cells. Cells in the G2-M phase were not observed. The conjugates blocked the cell cycle in the S phase and decreased the percentage of cells in the G0-G1 phase.
Źródło:
Acta Biochimica Polonica; 2010, 57, 1; 83-87
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Purification and functional reconstitution of intact ral-binding GTPase activating protein, RLIP76, in artificial liposomes.
Autorzy:
Singhal, Sharad
Singhal, Jyotsana
Cheng, JiZhong
Pikuła, Sławomir
Sharma, Rajendra
Zimniak, Piotr
Awasthi, Yogesh
Awasthi, Sanjay
Powiązania:
https://bibliotekanauki.pl/articles/1044153.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
RLIP76
glutathione-conjugate
anthracycline
transport
proteolysis
Opis:
We have recently shown that RLIP76, a ral-binding GTPase activating protein, mediates ATP-dependent transport of glutathione-conjugates (GS-E) and doxorubicin (DOX) (S. Awasthi et al., Biochemistry 39, 9327, 2000). Transport function of RLIP76 was found to be intact despite considerable proteolytic fragmentation in preparations used for those studies, suggesting either that the residual intact RLIP76 was responsible for transport activity, or that the transport activity could be reconstituted by fragments of RLIP76. If the former were true, intact RLIP76 would have a much higher specific activity for ATP-hydrolysis than the fragmented protein. We have addressed this question by comparing transport properties of recombinant RLIP76 and human erythrocyte membrane RLIP76 purified in buffers treated with either 100 or 500 μM serine protease inhibitor, PMSF. The purity and identity of recombinant and human erythrocyte RLIP76 was established by SDS/PAGE and Western-blot analysis. These studies confirmed the origin of the 38 kDa protein, previously referred to as DNP-SG ATPase, from RLIP76. Higher PMSF concentration resulted in lower yield of the 38 kDa band and higher yield of intact RLIP76 from both human and recombinant source. In contrast, the substrate-stimulated ATPase activity in presence of DNP-SG, doxorubicin, daunorubicin, or colchicine were unaffected by increased PMSF; similarly, ATP-dependent transport of doxorubicin in proteoliposomes reconstituted with RLIP76 was unaffected by higher PMSF. These results indicated that limited proteolysis by serine proteases does not abrogate the transport function of RLIP76. Comparison of transport kinetics for daunorubicin between recombinant vs human erythrocyte RLIP76 revealed higher specific activity of transport for tissue purified RLIP76, indicating that additional factors present in tissue purified RLIP76 can modulate its transport activity.
Źródło:
Acta Biochimica Polonica; 2001, 48, 2; 551-562
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transport functions and physiological significance of 76 kDa Ral-binding GTPase activating protein (RLIP76).
Autorzy:
Awasthi, Sanjay
Sharma, Rajendra
Yang, Yusong
Singhal, Sharad
Pikula, Slawomir
Bandorowicz-Pikula, Joanna
Singh, Shivendra
Zimniak, Piotr
Awasthi, Yogesh
Powiązania:
https://bibliotekanauki.pl/articles/1043688.pdf
Data publikacji:
2002
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
RLIP76
RalBP1
glutathione conjugate
multidrug resistance
transport
Opis:
We have recently demonstrated that a previously known Ral-binding GTPase activating protein, RLIP76, can also catalyze ATP-dependent transport of various structurally unrelated xeno- and endobiotics irrespective of their net charge (Awasthi et al., 2000, Biochemistry, 39: 9327). RLIP76 is a non-ATP binding cassette (ABC) protein but it has two ATP-binding sites and shows basal ATPase activity which is stimulated in the presence of its transport substrates (allocrites) such as doxorubicin (DOX) and S-(2,4-dinitrophenyl) glutathione (DNP-SG). Proteoliposomes reconstituted with purified RLIP76 catalyze ATP-dependent, saturable transport of DOX, as well as of glutathione-conjugates including leukotrienes (LTC4) and the GSH-conjugate of 4-hydroxynonenal (GS-HNE). In erythrocytes the majority of transport activity for DOX, GS-HNE, and LTC4 is accounted for by RLIP76. Cells exposed to mild oxidative stress show a rapid and transient induction of RLIP76 resulting in an increased efflux of GS-HNE and acquire resistance to oxidative stress mediated toxicity and apoptosis. Cells transfected with RLIP76 acquire resistance to DOX through increased efflux of the drug suggesting its possible role in the mechanisms of drug-resistance. In this article, we discuss the significance of transport functions of RLIP76 highlighting its role in the defense mechanisms against oxidative injury, and modulation of signaling mechanisms.
Źródło:
Acta Biochimica Polonica; 2002, 49, 4; 855-867
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The amide of galacturonic acid with lysine as an immunodominant component of the lipopolysaccharide core region from Proteus penneri 42 strain
Autorzy:
Palusiak, Agata
Maciejewska, Anna
Ługowski, Czesław
Różalski, Antoni
Powiązania:
https://bibliotekanauki.pl/articles/1039351.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
amide of galacturonic acid with lysine
anti-conjugate serum
core region
lipopolysaccharide
Proteus
Opis:
Most Proteus lipopolysaccharides (LPSs) contain uronic acids or their amides with different amino acids, which together with other negatively charged components account for the acidic character of such LPS molecules. Previous studies have shown the significance of an amide of galacturonic acid with lysine [D-GalA(L-Lys)] for serological specificity of O-antigens from few P. mirabilis strains. In this work, the immunodominant role of GalALys was indicated for the P. penneri 42 LPS core region. The studies also showed the serological identity of core oligosaccharides from P. penneri 42 (O71), P. mirabilis 51/57 (O28) and R14/S1959 strains.
Źródło:
Acta Biochimica Polonica; 2014, 61, 1; 129-132
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Functional reconstitution of Ral-binding GTPase activating protein, RLIP76, in proteoliposomes catalyzing ATP-dependent transport of glutathione conjugate of 4-hydroxynonenal.
Autorzy:
Sharma, Rajendra
Sharma, Abha
Yang, Yusong
Awasthi, Sanjay
Singhal, Sharad
Zimniak, Piotr
Awasthi, Yogesh
Powiązania:
https://bibliotekanauki.pl/articles/1043735.pdf
Data publikacji:
2002
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
RLIP76
4-hydroxynonenal
Ral-binding GTPase activating protein
transport
glutathione conjugate of 4-hydroxynonenal
Opis:
Earlier studies from our laboratories have shown that RLIP76, a previously described Ral-binding GTPase activating protein (Jullien-Flores et al., 1995, J. Biol. Chem. 270: 22473), is identical with the xenobiotic transporter DNP-SG ATPase, and can catalyze ATP-dependent transport of glutathione-conjugates as well as doxorubin (Awasthi et al., 2000, Biochemistry, 39: 9327). We have now reconstituted purified bacterially expressed RLIP76 in proteoliposomes, and have studied ATP-dependent uptake of the glutathione conjugate of 4-hydroxynonenal (GS-HNE) by these vesicles. Results of these studies show that RLIP76 reconstituted in proteoliposomes catalyzes ATP-dependent transport of GS-HNE against a concentration gradient. The transport of GS-HNE is saturable with respect to ATP as well as GS-HNE with Km values of 1.4 mM and 2.5 μM, respectively. These studies demonstrate that RLIP76 mediates active transport of GS-HNE, and are consistent with our previous work showing that RLIP76-mediated efflux of GS-HNE regulates the intracellular concentration of 4-HNE and thereby affects 4-HNE mediated signaling.
Źródło:
Acta Biochimica Polonica; 2002, 49, 3; 693-701
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Protective action of vitamin C against DNA damage induced by selenium-cisplatin conjugate.
Autorzy:
Błasiak, Janusz
Kowalik, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/1044192.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
endonuclease III
vitamin C
Se-Pt conjugate [(NH3)2Pt(SeO3)]
genotoxic effects of anticancer drugs
DNA damage
comet assay
DNA repair
Opis:
Genotoxicity of anticancer drugs is of a special interest due to the risk of inducing secondary malignancies. Vitamin C (ascorbic acid) is a recognized antioxidant and, since human diet can be easily supplemented with vitamin C, it seems reasonable to check whether it can protect against DNA-damaging effects of antitumor drugs. In the present work the ability of vitamin C to modulate cytotoxic and genotoxic effects of a cisplatin analog, conjugate (NH3)2Pt(SeO3), in terms of cell viability, DNA damage and repair in human lymphocytes was examined using the trypan blue exclusion test and the alkaline comet assay, respectively. The conjugate evoked a concentration-dependent decrease in the cell viability, reaching nearly 50% at 250 μM. (NH3)2Pt(SeO3) at 1, 10 and 30 μM caused DNA strand breaks, measured as the increase in the comet tail moment of the lymphocytes. The treated cells were able to recover within a 30-min incubation in a drug-free medium at 37°C. Vitamin C at 10 and 50 μM diminished the extent of DNA damage evoked by (NH3)2Pt(SeO3) but had no effect on the kinetics of DNA repair. The vitamin did not directly inactivate the conjugate. Lymphocytes treated with endonuclease III, which recognises oxidised pyrimidines, displayed a greater tail moment than those untreated with the enzyme, suggesting that the damages induced by the drug have, at least in part, an oxidative origin. Vitamin C can be considered a potential protective agent against side effects of antitumor drugs, but further research with both normal and cancer cells are needed to clarify this point.
Źródło:
Acta Biochimica Polonica; 2001, 48, 1; 233-240
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