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Spyridakou M, Tsimenidis K, Gkikas M, Steinhart M, Graf R, Floudas G. Effects of Nanometer Confinement on the Self-Assembly and Dynamics of Poly(γ-benzyl- l-glutamate) and Its Copolymer with Poly(isobutylene). Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Kostas Tsimenidis
- Department of Chemistry, University of Massachusetts Lowell, Lowell, Massachusetts 01854, United States
| | - Manos Gkikas
- Department of Chemistry, University of Massachusetts Lowell, Lowell, Massachusetts 01854, United States
| | - Martin Steinhart
- Institut für Chemie neuer Materialien, Universität Osnabrück, D-49069 Osnabrück, Germany
| | - Robert Graf
- Max Planck Institute for Polymer Research, 55128 Mainz, Germany
| | - George Floudas
- Department of Physics, University of Ioannina, 45110 Ioannina, Greece
- Max Planck Institute for Polymer Research, 55128 Mainz, Germany
- Institute of Materials Science and Computing, University Research Center of Ioannina (URCI), 45110 Ioannina, Greece
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Wu IL, Patterson MA, Carpenter Desai HE, Mehl RA, Giorgi G, Conticello VP. Multiple Site-Selective Insertions of Noncanonical Amino Acids into Sequence-Repetitive Polypeptides. Chembiochem 2013; 14:968-78. [DOI: 10.1002/cbic.201300069] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Indexed: 11/11/2022]
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Hwang Y, Je Y, Farrar D, West JE, Yu SM, Moon W. Piezoelectric properties of polypeptide-PMMA molecular composites fabricated by contact charging. POLYMER 2011. [DOI: 10.1016/j.polymer.2011.04.060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Cheung DL, Troisi A. Molecular structure and phase behaviour of hairy-rod polymers. Phys Chem Chem Phys 2009; 11:2105-12. [DOI: 10.1039/b818428c] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Panchenko T, Zhu WW, Montclare JK. Influence of global fluorination on chloramphenicol acetyltransferase activity and stability. Biotechnol Bioeng 2006; 94:921-30. [PMID: 16548001 DOI: 10.1002/bit.20910] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Varied levels of fluorinated amino acid have been introduced biosynthetically to test the functional limits of global substitution on enzymatic activity and stability. Replacement of all the leucine (LEU) residues in the enzyme chloramphenicol acetyltransferase (CAT) with the analog, 5',5',5'-trifluoroleucine (TFL), results in the maintenance of enzymatic activity under ambient temperatures as well as an enhancement in secondary structure but loss in stability against heat and denaturants or organic co-solvents. Although catalytic activity of the fully substituted CAT is preserved under standard reaction conditions compared to the wild-type enzyme both in vitro and in vivo, as the incorporation levels increase, a concomitant reduction in thermostability and chemostability is observed. Circular dichroism (CD) studies reveal that although fluorination greatly improves the secondary structure of CAT, a large structural destabilization upon increased levels of TFL incorporation occurs at elevated temperatures. These data suggest that enhanced secondary structure afforded by TFL incorporation does not necessarily lead to an improvement in stability.
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Affiliation(s)
- Tatyana Panchenko
- Department of Chemical and Biological Sciences, Polytechnic University, 6 Metrotech Center, Brooklyn, NY 11201, USA
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Yang Y, Xie X, Wu J, Mai YW. Synthesis and self-assembly of polystyrene-grafted multiwalled carbon nanotubes with a hairy-rod nanostructure. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/pola.21491] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Knaapila M, Stepanyan R, Torkkeli M, Lyons BP, Ikonen TP, Almásy L, Foreman JP, Serimaa R, Güntner R, Scherf U, Monkman AP. Influence of molecular weight on the phase behavior and structure formation of branched side-chain hairy-rod polyfluorene in bulk phase. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:041802. [PMID: 15903692 DOI: 10.1103/physreve.71.041802] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2004] [Indexed: 05/02/2023]
Abstract
We report on an experimental study of the self-organization and phase behavior of hairy-rod pi -conjugated branched side-chain polyfluorene, poly[9,9-bis(2-ethylhexyl)-fluorene-2,7-diyl]-i.e., poly[2,7-(9,9-bis(2-ethylhexyl)fluorene] (PF2/6) -as a function of molecular weight (M(n)) . The results have been compared to those of phenomenological theory. Samples for which M(n) =3-147 kg/mol were used. First, the stiffness of PF2/6 , the assumption of the theory, has been probed by small-angle neutron scattering in solution. Thermogravimetry has been used to show that PF2/6 is thermally stable over the conditions studied. Second, the existence of nematic and hexagonal phases has been phenomenologically identified for lower and higher M(n) (LMW, M(n) < M(*)(n) and HMW, M(n) > M(*)(n) ) regimes, respectively, based on free-energy argument of nematic and hexagonal hairy rods and found to correspond to the experimental x-ray diffraction (XRD) results for PF2/6 . By using the lattice parameters of PF2/6 as an experimental input, the nematic-hexagonal transition has been predicted in the vicinity of glassification temperature (T(g)) of PF2/6 . Then, by taking the orientation parts of the free energies into account the nematic-hexagonal transition has been calculated as a function of temperature and M(n) and a phase diagram has been formed. Below T(g) of 80 degrees C only (frozen) nematic phase is observed for M(n)< M(*)(n) = 10(4) g/mol and crystalline hexagonal phase for M(n) > M(*)(n) . The nematic-hexagonal transition upon heating is observed for the HMW regime depending weakly on M(n) , being at 140-165 degrees C for M(n) > M(*)(n). Third, the phase behavior and structure formation as a function of M(n) have been probed using powder and fiber XRD and differential scanning calorimetry and reasonable semiquantitative agreement with theory has been found for M(n) >or=3 kg/mol. Fourth, structural characteristics are widely discussed. The nematic phase of LMW materials has been observed to be denser than high-temperature nematic phase of HMW compounds. The hexagonal phase has been found to be paracrystalline in the (ab0) plane but a genuine crystal meridionally. We also find that all these materials including the shortest 10-mer possess the formerly observed rigid five-helix hairy-rod molecular structure.
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Affiliation(s)
- M Knaapila
- Department of Physics, University of Durham, South Road, Durham DH1 3LE, United Kingdom.
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Haider M, Megeed Z, Ghandehari H. Genetically engineered polymers: status and prospects for controlled release. J Control Release 2004; 95:1-26. [PMID: 15013229 DOI: 10.1016/j.jconrel.2003.11.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2003] [Accepted: 11/11/2003] [Indexed: 10/26/2022]
Abstract
Genetic engineering methodology has enabled the synthesis of protein-based polymers with precisely controlled structures. Protein-based polymers have well-defined molecular weights, monomer compositions, sequences and stereochemistries. The incorporation of tailor-made motifs at specified locations by recombinant techniques allows the formation of hydrogels, sensitivity to environmental stimuli, complexation with drugs and nucleic acids, biorecognition and biodegradation. Accordingly, a special interest has emerged for the use of protein-based polymers for controlled drug and gene delivery, tissue engineering and other biomedical applications. This article is a review of genetically engineered polymers, their physicochemical characteristics, synthetic strategies used to produce them and their biomedical applications with emphasis on controlled release.
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Affiliation(s)
- Mohamed Haider
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, USA
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Haba Y, Harada A, Takagishi T, Kono K. Rendering Poly(amidoamine) or Poly(propylenimine) Dendrimers Temperature Sensitive. J Am Chem Soc 2004; 126:12760-1. [PMID: 15469255 DOI: 10.1021/ja047755g] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The poly(amidoamine) dendrimers having terminal isobutyramide (IBAM) groups were prepared by the reaction of isobutyric acid and the amine-terminated poly(amidoamine) dendrimers with generations (G) of 2 to 5 by using a condensing agent, 1,3-dicyclohexylcarbodiimide. 1H and 13C NMR revealed that an IBAM group was attached to essentially every chain end of the dendrimers. While the IBAM-terminated G2 dendrimer was soluble in water, the IBAM-terminated G3, G4, and G5 dendrimers exhibited the lower critical solution temperatures (LCSTs) at 75, 61, and 43 degrees C, respectively. Because the density of the terminal IBAM groups in the periphery of the dendrimer progressively increases with increasing dendrimer generation, the interaction of the IBAM groups might take place more efficiently, resulting in a remarkable decrease in the LCST. In addition, attachment of IBAM groups to poly(propylenimine) dendrimers could give the temperature-sensitive property, indicating that this is an efficient method to render dendrimers temperature sensitive.
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Affiliation(s)
- Yasuhiro Haba
- Department of Applied Materials Science, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan
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Fukuto M, Heilmann RK, Pershan PS, Yu SM, Soto CM, Tirrell DA. Internal segregation and side chain ordering in hairy-rod polypeptide monolayers at the gas/water interface: An x-ray scattering study. J Chem Phys 2003. [DOI: 10.1063/1.1602058] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Stepanyan R, Subbotin A, Knaapila M, Ikkala O, ten Brinke G. Self-Organization of Hairy-Rod Polymers. Macromolecules 2003. [DOI: 10.1021/ma0259665] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R. Stepanyan
- Department of Polymer Science and Material Science Center, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands; Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow 119991, Russia; and Department of Engineering Physics and Mathematics, Helsinki University of Technology, P.O. Box 2200, FIN-02015 HUT, Espoo, Finland
| | - A. Subbotin
- Department of Polymer Science and Material Science Center, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands; Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow 119991, Russia; and Department of Engineering Physics and Mathematics, Helsinki University of Technology, P.O. Box 2200, FIN-02015 HUT, Espoo, Finland
| | - M. Knaapila
- Department of Polymer Science and Material Science Center, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands; Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow 119991, Russia; and Department of Engineering Physics and Mathematics, Helsinki University of Technology, P.O. Box 2200, FIN-02015 HUT, Espoo, Finland
| | - O. Ikkala
- Department of Polymer Science and Material Science Center, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands; Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow 119991, Russia; and Department of Engineering Physics and Mathematics, Helsinki University of Technology, P.O. Box 2200, FIN-02015 HUT, Espoo, Finland
| | - G. ten Brinke
- Department of Polymer Science and Material Science Center, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands; Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow 119991, Russia; and Department of Engineering Physics and Mathematics, Helsinki University of Technology, P.O. Box 2200, FIN-02015 HUT, Espoo, Finland
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Fukuto M, Heilmann RK, Pershan PS, Yu SM, Soto CM, Tirrell DA. Confinement-induced order of tethered alkyl chains at the water/vapor interface. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2002; 66:010601. [PMID: 12241332 DOI: 10.1103/physreve.66.010601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2001] [Indexed: 05/23/2023]
Abstract
Packing of tethered alkyl chains in Langmuir monolayers of a hairy-rod polypeptide poly[gamma-4-(n-hexadecyloxy)benzyl alpha,L-glutamate] on water has been studied by x-ray scattering measurements at room temperature. The rods lie parallel to the surface while the alkyl side chains segregate toward the vapor. Results indicate that the herringbone order of the alkyl chains is established initially by one-dimensionally confined chains between aligned rods and grows laterally with compression.
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Affiliation(s)
- M Fukuto
- Department of Physics and Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
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