Reversing-pulse electric birefringence of poly (γ-benzyl-L-glutamate). II. Field-strength dependence of steady-state and decay signals of well-fractionated samples

✍ Scribed by Kazuyoshi Ueda; Masaharu Mimura; Kiwamu Yamaoka

• Publisher: Wiley (John Wiley & Sons)
• Year: 1984
• Tongue: English
• Weight: 759 KB
• Volume: 23
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360230905

✦ Synopsis

The electric field dependence (up to 21 kV/cm) of the steady-state and decay signals has been examined on the four well-fractionated samples of poly(y-b~nzyl-L-glutamate), [Glu(OBzl)],,, in N,N-dimethylformamide at 535 nm and 20°C. Together with the data previously obtained from the reversing-pulse electric birefringence [Ueda, K., Nomura, M. & Yamaoka, K. ( 1983) Biopolymers 22, 2077-20901. the steady-state birefringence and field-free relaxation time were analyzed by a method that takes into account the polydispersity of the chain length. The weight-average chain length, ( ltJ, permanent dipole moment, (p,, 1, electric polarizability anisotropy, (Aa,<I, and the length-independent optical anisotropy factor were evaluated. The axial translation per residue was calculated for the [Glu(OBzl)], helix, but the uncertainty involved in the weight-average molecular weights, determined from light scattering by different investigators, makes the determination of the exact conformation of [Glu(OBzlj], difficult. The contribution of AaL, to electric field orientation was found to be significant, since Aa,, was approximately proportional to ltt,. A linear relationship also exists between p,< and I,,., when the [Glu(OBzl)],, helix is shorter than about 1200 A.