Reversing-pulse electric birefringence of nonconducting helical polypeptides in solutions: detection of the effect of applied electric field on polymer conformations from the relationship between the areas of buildup, reverse, and decay signals

Yamaoka, Kiwamu; Yamamoto, Shinobu; Ueda, Kazuyoshi

doi:10.1021/j100270a015

Cited by 14 publications

(18 citation statements)

References 5 publications

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“…The area for decay is, on the other hand, nearly independent of field strengths, indicating that the distribution of the chain lengths is narrow for the present [Glu(OBzl)J. sample. 15 • 33 Values of areas were extrapolated to the limiting low field (E 2 ->0) with appropriate curvatures, which have been shown to depend on the electric parameter (/3 2 )w/2(y)w. 13 This parameter can be evaluated from the llm and tm values of the Table I.…”

Section: Resultsmentioning

confidence: 99%

“…In fact, the field-on and field-off conformations of [Glu(OBz)Jn were reported to be the same at more elevated temperatures. 13 In pyridine and chloroform, area ratios are far less than unity, clearly showing the field-on and field-off properties disagree with each other. The nature of this field effect is not clarified at present.…”

Section: Area Relation Between Buildup Reverse and Decay Processesmentioning

confidence: 99%

“…13 In order to check this method, the areas were manually computed, in some cases, from the RPEB signal digitally plotted on a 1446 large-size I x I mm section paper. An actual RPEB signal was compared with the smoothed curve in Figure 2.…”

Section: Evaluation Of the Rpeb Areasmentioning

confidence: 99%

“…It is the area method, associated with the RPEB technique, that reveals the so far undetected but important field effect. It will be a future problem to relate, on a quantitative basis, this observed field effect with such factors as the pitch and twist angle of a helical backbone, 11 helical chain length, 13 and selective salvation surrounding the helical periphery.…”

Section: Area Relation Between Buildup Reverse and Decay Processesmentioning

confidence: 99%

“…The experimental results obtained in the low field region will be analyzed with a newly devised procedure, the area method. 13 …”

mentioning

confidence: 99%

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Reversing-Pulse Electric Birefringence of Poly(γ-benzyl L-glutamate) V. Field-Induced Changes of Electric and Hydrodynamic Properties in Helix-Forming Solvents as Revealed by Transient Signals

Yamaoka

Yamamoto

Kimura

et al. 1991

Polym J

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ABSTRACT:Reversing-pulse electric birefringence (RPEB) of poly(y-benzyl L-glutamate), [Glu(OBzl)]., with a weight-average molecular weight of 1.71 x 10 5 was measured at 20°C and at 535 nm in helix-forming organic solvents in the low field strength region (0---5 kV cm -1 ), with an emphasis on the transient signal. The theoretical formalism was given for detecting the effect of an applied electric pulse field on reversible change in the electric and hydrodynamic properties of [Glu(OBzl)]" from the normalized signal profiles, areas, and initial slopes of an RPEB signal. A standard experimental procedure was given for unraveling the field-induced change of the electric and hydrodynamic parameters, by utilizing the areas of buildup (Ae), reverse (AR), and decay (AD) processes at the limiting low field. The area ratio, Ae/[(l/2)AR +ADJ= 1, should hold regardless of the degree of polydispersity of a sample, if no direct field effect on polymer conformation is present. The ratio was found to be 0.95 in cyclohexanone, 0.93 in 2~chloroethanol, 0.81 in pyridine, and 0.74---0.81 in chloroform, all being less than unity. Thus, the electric moments and/or the chain length of the [Glu(OBzl)Jn helix were verified to change reversibly to varying extent during the electric field orientation. KEY WORDSReversing-Pulse Electric Birefringence / Poly(y-benzyl Lglutamate) / Field Effect/ Electro-Hydrodynamic Property/ Area Method/ With the aim of perfecting the reversingpulse electric birefringence (RPEB) method and applying it to macromolecules in solution to elucidate the electric, optical and hydrodynamic properties, the RPEB study has been carried out in our laboratory on many biopolymers and related polyelectrolytes. 1 -16 A major problem associated with these systems is polydispersity regarding the molecular weight and chain length. This problem is almost always encountered with natural macromolecules of biological interest, which are prepared by extraction from living organisms, and also with the synthetic polymers, which are prepared by in vitro polymerization. Thus, the polydispersity effect must be taken into account for quantitative analysis of the electric birefringence signal. 1 7 Yoshioka and his coworkers were the first who seriously considered this effect in the analysis of the single square-wave pulse electric birefringence (SPEB) data of poly(o:-L-glutamic acid). 18 -21 The RPEB method is usually superior to the conventional SPEB method in that the transient signal at low fields can yield sufficient infonnation on the polydispersity effect and the electric and hydrodynamic properties of the rodlike or helical polymers. 1 7 * To whom correspondence should be addressed. Another major problem associated with an orienting electric pulse field is the direct field effect on the polymer conformation, which may change concurrently with molecular orientation. This field effect has seldom been studied mostly because of the difficulty involved in detecting such field-induced conformational changes for polydisperse samples....

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Section: Resultsmentioning

confidence: 99%

Section: Area Relation Between Buildup Reverse and Decay Processesmentioning

confidence: 99%

Section: Evaluation Of the Rpeb Areasmentioning

confidence: 99%

Section: Area Relation Between Buildup Reverse and Decay Processesmentioning

confidence: 99%

“…The experimental results obtained in the low field region will be analyzed with a newly devised procedure, the area method. 13 …”

mentioning

confidence: 99%

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Reversing-Pulse Electric Birefringence of Poly(γ-benzyl L-glutamate) V. Field-Induced Changes of Electric and Hydrodynamic Properties in Helix-Forming Solvents as Revealed by Transient Signals

Yamaoka

Yamamoto

Kimura

et al. 1991

Polym J

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Transition Phenomena in Poly(diacetylene) Solutions Studied by Electric Birefringence Measurements

Hennecke

1989

Ber Bunsenges Phys Chem

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An external electric field induces strong birefringence in solutions of poly(diacetylenes) when they are in the red (low temperature) form. The transient behaviour and the field‐strength dependence of the steady‐state birefringence reveal that the orientation of particles is predominantly due to a permanent dipole moment rather than to the anisotropy of polarizability. The estimated permanent dipole moments are in the order of tenthousand Debye units, this order of magnitude being incompatible with single macromolecules. Thus the view that aggregated particles are formed at low temperatures is supported by our experiments.

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Electrooptics of β-FeOOH particle in aqueous media

Peikov

Sasai

Tanigawa

et al. 2006

Journal of Colloid and Interface Science

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Reversing-pulse electric birefringence of nonconducting helical polypeptides in solutions: detection of the effect of applied electric field on polymer conformations from the relationship between the areas of buildup, reverse, and decay signals

Cited by 14 publications

References 5 publications

Reversing-Pulse Electric Birefringence of Poly(γ-benzyl L-glutamate) V. Field-Induced Changes of Electric and Hydrodynamic Properties in Helix-Forming Solvents as Revealed by Transient Signals

Reversing-Pulse Electric Birefringence of Poly(γ-benzyl L-glutamate) V. Field-Induced Changes of Electric and Hydrodynamic Properties in Helix-Forming Solvents as Revealed by Transient Signals

Transition Phenomena in Poly(diacetylene) Solutions Studied by Electric Birefringence Measurements

Electrooptics of β-FeOOH particle in aqueous media

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