Electromechanical Properties of an Ultrathin Layer of Directionally Aligned Helical Polypeptides

Jaworek, Thomas; Neher, Dieter; Wegner, Gerhard; Wieringa, R.H; Schouten, A.J.

doi:10.1126/science.279.5347.57

Cited by 138 publications

(111 citation statements)

References 37 publications

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“…Furthermore, direct polar rod-like molecules have been suggested to assemble in a twisted-grain boundary mesophase that probably displays piezoelectric properties (Jaworek et al (1978); Vidal and Mello, 2001;Vidal, 2003). The expressive influence of a mechanical effect as is the exercise on the structure of the rat calcaneal tendon can be revealed by Fig.…”

Section: Morphological Considerationsmentioning

confidence: 96%

Structural organization of collagen fibers in chordae tendineae as assessed by optical anisotropic properties and Fast Fourier transform

Vidal

Mello

2009

Journal of Structural Biology

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The structural and supraorganizational arrangement of the chordae tendineae components is very important for a better understanding of their morphophysiological relationships. This study aims to evaluate the degree of statistical variability of the distribution and orientation of collagen fibers and their undulations (crimps), in porcine chordae tendineae. Polarization microscopy, in association with image analysis, was used for the analysis of birefringent images and detection of surface plots, Fast Fourier transforms, and form birefringence curve profiles. A marked variability in the collagen fiber's twisted and intertwined orientation was found not only along the long axis of the chordae tendineae but also in their 3-D structure, including that of the crimp structures. Crimp was demonstrated to not represent a homogeneous distribution of bands; the best methods to quantify its variability were the Fast Fourier transform and the line profile extended along the long axis of the chordae tendineae. Collagen fiber rings, considered to possibly protecting the integrity of the chordae tendineae, were observed to wrap around them. A statistically helical structure is assumed for the supraorganization of the collagen fibers in the chordae tendineae, which is suggested here to be a chiral body.

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Section: Morphological Considerationsmentioning

confidence: 96%

Structural organization of collagen fibers in chordae tendineae as assessed by optical anisotropic properties and Fast Fourier transform

Vidal

Mello

2009

Journal of Structural Biology

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“…Jaworek et al studied the piezo-electric properties [47]. The field-induced change in film thickness were dominated by a inverse-piezoelectric effect and demonstrated that the helices were in a parallel arrangement.…”

Section: Pblg Monomolecular Filmsmentioning

confidence: 99%

Sum-frequency spectroscopy and imaging of aligned helical polypeptides

Knoesen

Pakalnis

Zhao

et al. 2004

IEEE J. Select. Topics Quantum Electron.

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Abstract-The sum-frequency spectroscopy signatures of NH-(amide A) and C = O (amide I) groups, the amide segments in all proteins, are measured in thin films that consist of an ensemble of right-handed, helical poly--benzyl-L-glutamate (PBLG) macromolecules that are endgrafted and self-organized into a monomolecular film with a large degree of unidirectional order. Distinct sum-frequency spectral signatures associated with the amide A and the amide I bands are observed because of a strong noncentro-symmetry produced by intra-and intermolecular forces. Hydrogen bonding self-organizes amino and acidic groups within the molecular helical scaffold. In an endgrafted thin film, repulsive electrostatic forces between PBLG macromolecules stabilize the organization between molecules. The average orientation of the PBLG chain was measured. Imaging scans using sum-frequency generation, complemented by atomic force microscopy, were used to investigate the uniformity of orientation of the PBLG chains.

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“…Peptides of poly(α-benzyl-L-glutamate) (PBLG) are well known to form α-helical secondary structure stabilized by intramolecular hydrogen bonds [18]. The α-helical structure is thought to give rise to a rigid-rod structure, and PBLG has been employed as a typical model of rigid-rod building block in linear rod-coil block copolymers, for example, poly(ethylene oxide) [19], poly(N-isopropylacrylamide) [20], poly(dimethylsiloxane) [21], poly(styrene) (PS) [22], poly(butadiene) [23], poly(isoprene) (PI) [24], poly(fluorine) [25], and poly{2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene} [26] have been used so far as nonpeptide block.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and self-assembly in bulk of star-shaped block copolymers based on helical polypeptides

Lin

Zhou

et al. 2014

Colloid Polym Sci

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A series of star-shaped copolymers containing poly (styrene) (PS) and poly(γ-benzyl-L-glutamate) (PBLG) were synthesized by click reaction from alkyne-and azidefunctionalized homopolymers. The α-azide PS star-shaped homopolymer was synthesized by copper-mediated atom transfer radical polymerization from a bromine-containing star-shaped initiator, and α-alkyne PBLG homopolymers were synthesized by ring-opening polymerization of γ-benzyl-L-glutamate N-carboxyanhydride with an aminocontaining α-alkyne initiator. The molecular structures of the homopolymers and star-shaped block copolymers were confirmed by 1 H nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy (FTIR), and gel permeation chromatography analysis. The self-assembling behavior of the star-shaped block copolymers in bulk was investigated using wide-angle X-ray diffraction, and smallangle X-ray scattering. For star-shaped block copolymer at lower f PS of~0.27, PBLG segment was assigned to a hexagonally packed-cylinder structure (Φ H ) based on the rod-like α-helix conformation as shown in FTIR spectra. By increasing f PS to~0.42, a proposed microphase-separated doublehexagonal morphology was observed, in which PBLG rods formed the core of the columns by interdigitated packing in Φ H phase with PS domain as the matrix in a larger hexagonal columnar structure. The proposed structure was based on calculation from the simulated molecular length of each block of the copolymer and experimental analyses.

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Electromechanical Properties of an Ultrathin Layer of Directionally Aligned Helical Polypeptides

Abstract: Electromechanical properties of an ultrathin layer of directionally aligned helical polypeptides Jaworek, T.; Neher, D.; Wegner, G.; Wieringa, R.H.; Schouten, A.J.

Cited by 138 publications

References 37 publications

Structural organization of collagen fibers in chordae tendineae as assessed by optical anisotropic properties and Fast Fourier transform

Structural organization of collagen fibers in chordae tendineae as assessed by optical anisotropic properties and Fast Fourier transform

Sum-frequency spectroscopy and imaging of aligned helical polypeptides

Synthesis and self-assembly in bulk of star-shaped block copolymers based on helical polypeptides

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