• Title/Summary/Keyword: hydrophilic chain

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Self-assembly of Amphiphilic Zinc Chlorins in an Aqueous Medium as a Model for Chlorosome of Green Photosynthetic Bacteria

  • Miyatake, Tomohiro;Kato, Syuusaku;Tamiaki, Hitoshi;Fujiwara, Manabu;Matsushita, Takayuki
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.347-349
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    • 2002
  • Synthetic zinc chlorins possessing a hydrophylic polyoxyethylene chain at the 17 -position were prepared. An amphiphilic zinc chlorin possessing a single chIorin moiety showed absorption maxima at 675 nm in an aqueous medium, indicating that the zinc chIorin did not form large aggregates but a dimeric structure. In contrast, amphiphilic zinc chlorin dyads in which two zinc chlorin moieties were connected with a hydrophilic polyoxyethylene linkage showed red-shifted absorption band around 720-740 nm in an aqueous medium. The result indicated that the amphiphilic zinc chlorin dyad self-aggregated to form chlorosome-like oligomer.

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Effect of associating polymer on the dispersion stability and rheology of suspensions

  • Otsubo, Yasufumi;Horigome, Misao
    • Korea-Australia Rheology Journal
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    • v.15 no.1
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    • pp.27-33
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    • 2003
  • Associating polymers are hydrophilic long-chain molecules to which a small amount of hydrophobic groups (hydrophobes) is incorporated. In aqueous solution, the association interactions result in the formation of three-dimensional network through flowerlike micelles at high concentrations. In colloidal suspensions, the associating polymers act as flocculated by bridging mechanism. The rheological properties of suspensions flocculated by associating polymers end-capped with hydrophobes are studied in relation to the bridging conformation. At low polymer concentrations, the polymer chains effectively form bridges between particles by multichain association. The suspensions are highly flocculated and show typical viscoelastic responses. When the polymer concentration is increased above the absorbance at saturation, the excess polymer chains remaining in the solution phase build up three-dimensional network by associating interactions. Since the presence of particles does not significantly influence the network structures in the medium, the relative viscosity, which gives a measure of the degree of flocculation is decreased with increasing polymer concentration. The bridging conformation and flocculation level vary strongly depending on the polymer concentrations.

Durable Hydrophilic Finish of PET Fabrics with Ethoxylated Alkylaminoanthraquinone (Ethoxylated Alkylaminoanthraquinone에 의한 PET직물의 내구성 친수화가공)

  • 최영주;윤남식
    • Textile Coloration and Finishing
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    • v.15 no.4
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    • pp.51-56
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    • 2003
  • Poly(ethylene terephthalate) (PET) fabrics were dyed with a series of ethoxylated alkylaminoanthraquinone dyes synthesized by the reaction of 1-aminoanthraquinone with poly(ethylene glycol) via a series of methylene spacer, and their hydrophilicity and durability to laundering were investigated. The results obtained are as follows: 1) Ethoxylated alkylaminoanthraquinone were successfully exhausted on PET fabric without any aid of chemical auxiliary. 2) The wettability of the dyed PET fabric was increased with the length of ethoxylate chain. 3) The durability of the wettability was good enough as to maintain the initial wettability even after 30 repeated launderings.

Cloning and Characterization of Ribosome-associated Membrane Protein 4 (RAMP4) gene in silkworm Bombyx mori

  • Yao Qin;Hu Zhigang;Xu Jiaping;Chen Keping
    • International Journal of Industrial Entomology and Biomaterials
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    • v.10 no.2
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    • pp.125-129
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    • 2005
  • Ribosome-associated membrane protein 4 (RAMP4) is a membrane protein that exposes its N-terminal hydrophilic portion on the cytoplasmic side and spans the membrane close to the C-terminal end. RAMP4 has previously been reported to belong to the set of proteins that remains associated with membrane-bound ribosomes, and controls the glycosylation of major histocompatbility complex class II-associated invariant chain. RAMP4 also may be relative to the stabilization of membrane proteins in response to stress, with other components of translocon, and molecular chaperons in ER. Application of 5'-RACE technique with specially designed primer, we cloned a 715 bp cDNA fragment which contains a 195 bp ORF, termed RAMP4. The deduced protein has 64 amino acid residues and contains a putative transmembrane-spanning domain at the COOH terminus.

Durable Antistatic and Hydrophillic Finishing of Nylon Using Ethoxylated Hexylaminoanthraquinones (Ethoxylated Hexylaminoanthraquinone에 의한 나일론의 내구성 대전방지가공 및 친수화 가공)

  • Kim Myung-Soon;Park Hyun-Min;Yoon Nam-Sik
    • Textile Coloration and Finishing
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    • v.17 no.2 s.81
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    • pp.26-30
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    • 2005
  • Nylon fabric is widely used in stocking, inner wear, sports wear, and casual wear, but has a defect of easy electric static charging. Accordingly there has been great demand for the hydrophillic finishing technology that could be applied to nylon fiber more easily and efficiently. In this study, ethoxylated hexylantinoanthraquinones were exhausted onto nylon from aqueous bath, and hydrophillicity of the nylon was discussed. In the treatment of nylon fabrics with ethoxylated hexylaminoanthraquinones, they were successfully exhausted onto nylon fabric without any aid of chemical auxiliary. The hydrophilicity of the dyed nylon fabrics were increased with the length of ethoxylate chain. The durability of antistatic and hydrophilic characteristics was good enough as to maintain the initial properties even after 30 repeated launderings.

Application of Poly (Ethylene Glycol)-Bound NAD in Model Enzyme Reactor

  • Urabe, Itaru
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1986.12a
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    • pp.510.1-510
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    • 1986
  • Many enzymes require the participation of readily dissociable coenzymes as NAD for thir catalytic activities. The continuous utilization of the enzymes requires the retention and regeneration of the coenzymes. For this purpose, several kinds of macromolecular NAD derivatives have been prepared by covalently attaching NAD to watersoluble polymers. We have prepared poly (ethylene glycol)-bound NAD (PEG-NAD) by coupling N$\^$6/-(2-carboxyethyl)-NAD to one terminal of ${\gamma}$ $\omega$-diaminoly (ethylene glycol) (Mr 3000) with water-soluble carbodiimide. PED-NAD thus obtained has one NAD moiety located at a terminal of the linear, flexible and hydrophilic chain of poly (ethylene glycol). PED-NAD has good coenzyme activity for various dehydrogenases and is applicable in a continuous enzyme reactor. To use these macromolecular NAD derivatives in an enzyme reactor, it si necessary to understand the behavior of the system in which the reactions of dehydrogenases are coupled by the recycling of the NAD derivative. We investigated the kinetic properties of a continuous enzyme reactor containing lactate dehydrogenase, alcohol dehydrogenase and PEG-NAD. The steady-state behavior of the enzyme reactor is explained by a simple kinetic model.

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Synthesis and Their Physical Properties of Cationic Surfactants bearing Hydrophobic Chains of Aromatic Subtituents (방향족 치환기의 소수성 사슬을 갖는 양이온 계면활성제의 합성과 이의 물리화학적 특성 연구)

  • Ahn, Beom-Shu
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.3
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    • pp.380-386
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    • 2013
  • N,N,N-Trimethyl-10-nitrophenoxy decylammonium bromide (N10TAB) and N,N,N,N-Tetramethyl-bis-[10-nitrophenoxy decyl]-1,6-hexanediammonium dibromide (N10-6-10N), bearing aromatic nitrophenoxy group in the end of their hydrophobic chains have been prepared, and their properties in aqueous solutions have been studied by conductivity and H-NMR spectroscopy. Below the critical micelle concentration N10-6-10N form premicelle with two or three surfactant molecules. Beyond the critical micelle concentration two molecules have strong self-aggregation ability and form micelles of rather small size and with small aggregation numbers. H-NMR at different concentrations give the informations on the environmental changes of the surfactants on their micellization progress.

Study on Preparation of PAHPV LB Films and Their Luminescent Characterisrics (PAHPV LB막의 제작 및 그 발광 특성에 관한 연구)

  • Hwang, Jang-Hwan;Choo, Jung-Woo;Kim, Young-Kwan;Sohn, Byoung-Chung
    • Journal of the Korean Applied Science and Technology
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    • v.14 no.2
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    • pp.71-79
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    • 1997
  • Ultra-thin films of poly[2-[4-(9-(10-phenyl)anthracenyl)phenoxy)hexyloxy]]-1,4-phenylenevinyleylene(PAHPV) were prepare-d on the hydrophilic ITO substrate by Langmuir-Blodgett(LB) technique. ${\lambda}_{max}$ in the photoluminescence spectrum of these films was 458nm at the excitation wavelength of 365nm before thermal treatment, which comes from diphenylanthracene side chain of PAHPV. It was also confirmed with UV-Vis spectrometer that ultra-thin LB films of PAHPV precursor polymer were prepared well. After thermal treatment for conjugation of PAHPV precursor polymer, ${\lambda}_{max}$ in the photoluminescence spectrum of these films changed to 365nm, which means that the conjugation of these PAHPV films was completed.

A Study on the Properties of FRP Insulation Materials by Thermal-Accelerated Degradation (고온 가속열화에 의한 FRP 절연재료의 특성변화에 관한 연구)

  • Lee, B.S.;Chung, U.N.;Han, S.O.;Park, C.S.;Kang, D.H.;Na, D.G.;Lee, D.C.
    • Proceedings of the KIEE Conference
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    • 1997.07d
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    • pp.1543-1545
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    • 1997
  • In this work, properties of FRP insulation materials by thermal-accelerated degradation were investigated. Usually, most degradations cause the hydrophilic to decrease the contact angle and surface properties. But, in this work on thermal-degradated FRP, we can confirm the introduction of hydrophobic properties by cross-linking and the ablation of small-molecules rather than chain scission and oxidation. Hydrophobic introduction in thermal-degradated FRP caused the increase of electrical insulation on treated FRP surface. But, Tensile strength decreased steeply on FRP being exposed higher temperature.

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Partial Characterization of Soybean cDNA Encoding CTP: Phosphocholine Cytidylyltransferase

  • Sung Ho Cho
    • Journal of Plant Biology
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    • v.38 no.4
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    • pp.359-364
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    • 1995
  • As the first step to elucidate the relationship between the structure and function of CTP:phosphocholine cytidylyltransferase (EC 2.7.7.15) in plants, the partial nucleotide sequence of soybean cytidylyltransferase cDNA was determined using a polymerase chain reaction (PCR). Degenerate oligonucleotide primers were synthesized from the conserved region revealed from the rat and yeast cytidylyltransferase DNA sequences. The catalytic domain region showed 78 and 76% homology with the rat and yeast amino acid sequences, respectivly. The hydropathy profile indicated that the C-terminal non-catalytic portion of the protein was very hydrophilic, and in the region between the catalytic domain and the C-terminal region, there was a large amphipathic $\alpha$-helical domain that was believed to bind the membrane surface in the active formation. There are 7 potential sites for phosphorylation by protein kinase C and 4 potential sites for phosphorylation by Ca2+/calmodulin kinase within the determined sequence.

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