PHOTO-INDUCED POLYPEPTIDE MEMBRANE POTENTIAL CHANGES BY cis–trans ISOMERISM IN SIDE-CHAIN AZOBENZENE GROUPS

1984 ◽  
Vol 13 (11) ◽  
pp. 1963-1966 ◽  
Author(s):  
Akira Takizawa ◽  
Morimasa Sato ◽  
Takatoshi Kinoshita ◽  
Yoshiharu Tsujita
Keyword(s):  
Membrane Potential ◽  
Side Chain ◽  
Azobenzene Groups

Syntheses and properties of polyurethanes containing side-chain azobenzene groups

2003 ◽  
Vol 52 (5) ◽  
pp. 658-663 ◽  
Author(s):  
Mi-Ra Kim ◽  
Phan-Seok Kim ◽  
Eun-Hee Kang ◽  
Chang-Sik Ha ◽  
Jin-Kook Lee
Keyword(s):  
Side Chain ◽  
Azobenzene Groups

An activatable anticancer polymer–drug conjugate based on the self-immolative azobenzene motif

2017 ◽  
Vol 5 (24) ◽  
pp. 4574-4578 ◽  
Author(s):  
Taejun Eom ◽  
Wonjae Yoo ◽  
Yong-Deok Lee ◽  
Jae Hyung Park ◽  
Youngson Choe ◽  
...  
Keyword(s):  
Anticancer Drug ◽  
Cellular Uptake ◽  
Graft Copolymer ◽  
The Self ◽  
Side Chain ◽  
Synthetic Graft ◽  
Drug Conjugate ◽  
Self Immolation ◽  
Azobenzene Groups

Triggered cellular uptake of a synthetic graft copolymer carrying an anticancer drug is achieved through self-immolation of the side-chain azobenzene groups.

Synthesis and Characterization of a Novel Liquid Crystalline Polymer Bearing Azobenzene

2011 ◽  
Vol 181-182 ◽  
pp. 47-50
Author(s):  
Xin De Tang ◽  
Ye Chen ◽  
Xin Wang ◽  
Fa Qi Yu ◽  
Mei Shan Pei
Keyword(s):  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Gel Permeation Chromatography ◽  
Crystalline Polymer ◽  
Side Chain ◽  
Scanning Calorimetry ◽  
Polymer Bearing ◽  
Mesomorphic Properties ◽  
Azobenzene Groups

A novel liquid crystalline polymer bearing azobenzene groups in both main chain and side chain has been successfully synthesized by atom transfer radical polymerization (ATRP). Dual bromide-terminated azobenzene was used as the initiator for the ATRP of azobenzene-containing monomer (M6C). The structure of the resulting polymer was confirmed by nuclear magnetic resonance (NMR), and the molecular weight and its dispersity was characterized by gel permeation chromatography (GPC). The mesomorphic properties of this novel polymer were characterized by means of polarized optical microscopy (POM) and differential scanning calorimetry (DSC). The results demonstrated that this polymer can form mesophases.

Photocontrol of polypeptide membrane functions by cis-trans isomerization in side-chain azobenzene groups

1986 ◽  
Vol 19 (1) ◽  
pp. 51-55 ◽  
Author(s):  
Takatoshi Kinoshita ◽  
Morimasa Sato ◽  
Akira Takizawa ◽  
Yoshiharu Tsujita
Keyword(s):  
Side Chain ◽  
Trans Isomerization ◽  
Azobenzene Groups

Photomodulation of the hydrophilic properties of acrylic polymers containing side-chain azobenzene chromophores

1995 ◽  
Vol 73 (11) ◽  
pp. 1849-1854 ◽  
Author(s):  
Nicola Tirelli ◽  
Angelina Altomare ◽  
Roberto Solaro ◽  
Francesco Ciardelli
Keyword(s):  
Structural Parameters ◽  
Radical Copolymerization ◽  
Side Chain ◽  
Suspension Stability ◽  
Trans Form ◽  
Free Radical Copolymerization ◽  
Acrylic Polymers ◽  
Turbidimetric Method ◽  
Polymer Properties ◽  
Azobenzene Groups

Partially hydrophilic polymers have been prepared by free-radical copolymerization of trans-4-acryloyloxyazobenzene with N-tert-butylacrylamide and N-isopropylacrylamide. A turbidimetric method has been adapted to investigate the dependence of the polymer hydrophilic–hydrophobic balance on chemical composition and extent of photoisomerization of side-chain azobenzene chromophores. Irradiation at 366 nm of polymer suspension in THF–water induces the isomerization of azobenzene groups from the planar apolar trans form to the nonplanar polar cis form. Correspondingly, the solution turbidity is appreciably modified. Experimental results are discussed in terms of polymer structural parameters. Suspension stability and the possibility of carrying out photochemical cycles have been also investigated. Keywords: photochromic polymers, photoresponsive polymer, photomodulation of polymer properties, azobenzene-containing polymers, acryloyloxyazobenzene, N-tert-butylacrylamide.

Combined Main-Chain/Side-Chain Liquid Crystalline Polymer with Main-Chain On the basis of “Jacketing” Effect and Side-Chain Containing Azobenzene Groups

2011 ◽  
Vol 44 (19) ◽  
pp. 7600-7609 ◽  
Author(s):  
He-Lou Xie ◽  
Shao-Jie Wang ◽  
Guan-Qun Zhong ◽  
Yi-Xin Liu ◽  
Hai-Liang Zhang ◽  
...  
Keyword(s):  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Main Chain ◽  
Crystalline Polymer ◽  
Side Chain ◽  
Azobenzene Groups

scholarly journals Susceptibility of β1 Na+-K+ Pump Subunit to Glutathionylation and Oxidative Inhibition Depends on Conformational State of Pump

2012 ◽  
Vol 287 (15) ◽  
pp. 12353-12364 ◽  
Author(s):  
Chia-Chi Liu ◽  
Alvaro Garcia ◽  
Yasser A. Mahmmoud ◽  
Elisha J. Hamilton ◽  
Keyvan Karimi Galougahi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Membrane Potential ◽  
Angiotensin Ii ◽  
Conformational Changes ◽  
Ventricular Myocytes ◽  
Conformational State ◽  
Side Chain ◽  
Voltage Dependent ◽  
Cytosolic Glutathione ◽  
And Function

Glutathionylation of cysteine 46 of the β1 subunit of the Na+-K+ pump causes pump inhibition. However, the crystal structure, known in a state analogous to an E2·2K+·Pi configuration, indicates that the side chain of cysteine 46 is exposed to the lipid bulk phase of the membrane and not expected to be accessible to the cytosolic glutathione. We have examined whether glutathionylation depends on the conformational changes in the Na+-K+ pump cycle as described by the Albers-Post scheme. We measured β1 subunit glutathionylation and function of Na+-K+-ATPase in membrane fragments and in ventricular myocytes. Signals for glutathionylation in Na+-K+-ATPase-enriched membrane fragments suspended in solutions that preferentially induce E1ATP and E1Na3 conformations were much larger than signals in solutions that induce the E2 conformation. Ouabain further reduced glutathionylation in E2 and eliminated an increase seen with exposure to the oxidant peroxynitrite (ONOO−). Inhibition of Na+-K+-ATPase activity after exposure to ONOO− was greater when the enzyme had been in the E1Na3 than the E2 conformation. We exposed myocytes to different extracellular K+ concentrations to vary the membrane potential and hence voltage-dependent conformational poise. K+ concentrations expected to shift the poise toward E2 species reduced glutathionylation, and ouabain eliminated a ONOO−-induced increase. Angiotensin II-induced NADPH oxidase-dependent Na+-K+ pump inhibition was eliminated by conditions expected to shift the poise toward the E2 species. We conclude that susceptibility of the β1 subunit to glutathionylation depends on the conformational poise of the Na+-K+ pump.

scholarly journals Toxicity and Loss of Mitochondrial Membrane Potential Induced by Alkyl Gallates in Trypanosoma cruzi

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Rogério Andréo ◽  
Luís Octávio Regasini ◽  
Maicon Segalla Petrônio ◽  
Bruna Galdorfini Chiari-Andréo ◽  
Aline Tansini ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mechanism Of Action ◽  
Social Problem ◽  
Mitochondrial Membrane ◽  
Side Chain ◽  
Synergistic Activity ◽  
Alkyl Gallates ◽  
Structure Activity ◽  
The World

American trypanosomiasis or Chagas disease is a debilitating disease representing an important social problem that affects, approximately, 10 million people in the world. The main aggravating factor of this situation is the lack of an effective drug to treat the different stages of this disease. In this context, the search for trypanocidal substances isolated from plants, synthetic or semi synthetic molecules, is an important strategy. Here, the trypanocidal potential of gallates was assayed in epimastigotes forms of T. cruzi and also, the interference of these substances on the mitochondrial membrane potential of the parasites was assessed, allowing the study of the mechanism of action of the gallates in the T. cruzi organisms. Regarding the preliminary structure-activity relationships, the side chain length of gallates plays crucial role for activity. Nonyl, decyl, undecyl, and dodecyl gallates showed potent antitrypanosomal effect (IC50 from 1.46 to 2.90 μM) in contrast with benznidazole (IC50 = 34.0 μM). Heptyl gallate showed a strong synergistic activity with benznidazole, reducing by 105-fold the IC50 of benznidazole. Loss of mitochondrial membrane potential induced by these esters was revealed. Tetradecyl gallate induced a loss of 53% of the mitochondrial membrane potential, at IC50 value.

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