Electrical and hydrodynamical properties of polypeptides in solution. I. Poly(L-glutamic acid) in methanol-water mixtures

✍ Scribed by Mitsuhiro Matsumoto; Hiroshi Watanabe; Koshiro Yoshioka

• Publisher: Wiley (John Wiley & Sons)
• Year: 1968
• Tongue: English
• Weight: 480 KB
• Volume: 6
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1968.360060704

✦ Synopsis

The electric birefririgeiice of poly(L-glutamic acid) (PLGA) in methanol-water mixtnres has been measiired by the use of the rectangular pulse technique at 25°C. The permanent dipole moment, the anisotropy of electriral polarizability, and the optical anisotropy factor of PLGA in solution were obtained from the dependence of the steady-state birefringence on the electric field strength. Further, the mean length of PLGA in solution was calculated by a parameter method developed for analyzing the decay curve of electric birefringence. The permanent $pole moment per unit length obtained from these studies was 2.06, 2.48, 2&, 2.66 D/A in pure methanol, 10, 30, and 50 vol-% water, respectively. The inrrease of water content caused the decrease of the mean length and broadened the length distribution of PLGA. These results are discussed in relation to the viscosity and the elertrical conductivity of PLGA solutions.

* The refractive indicei of water and methanol are nearly identical.