Abstract
Block and random copolypeptides of γ-benzyl L-glutamate and L-alanine of narrow molecular weight distribution were synthesized by successive polymerization of the corresponding N-carboxy α-amino acid anhydrides with initiation by n-butylamine. Optical rotatory dispersion data show that the copolypeptides studied are essentially α-helical in m-cresol in a temperature range between 10 and 50°C. Dielectric dispersion and viscosity data for m-cresol solutions indicate that the copolypeptides have a rodlike molecular shape. The dielectric dispersion data in m-cresol as a function of copolymer composition gave 6.4±0.1 D for the monomeric dipole moment of L-alanine residue. This value is larger than those reported for other polypeptides with polar side chains, and suggests that the side chain dipoles on the average run antiparallel to the backbone dipoles. For polypeptides with polar side chains, the monomeric dipole moment was found to increase with the length of the side chain. This is ascribed to the increased rotational freedom of the longer side chain, which tends to reduce the side chain contribution to the total dipole moment.
Similar content being viewed by others
Article PDF
References
A. Wada, in “Polyamino Acids, Polypeptides, and Proteins,” M. A. Stahmann, Ed., Univ. Wisconsin Press, Madison, 1962, p 131.
A. Wada, in “Poly-α-Amino Acids,” G. D. Fasman, Ed., Marcel Dekker, New York, 1967, Chapter 9.
A. Wada, Bull. Chem. Soc., Jpn., 33, 822 (1960).
A. Wada, J. Chem. Phys., 31, 495 (1959).
M. Sharp, J. Chem. Soc., A, 1596 (1970).
E. H. Erenrich and H. A. Scheraga, Macromolecules, 5, 746 (1972).
G. D. Fasman, in “Polyamino Acids, Polypeptides, and Proteins,” M. A. Stahmann, Ed., Univ. Wisconsin Press, Madison, 1962, p 221.
J. R. Parrish, Jr. and E. R. Blout, Biopolymers, 11, 1001 (1972).
A. Nakajima and M. Murakami, Biopolymers, 11, 1295 (1972).
A. Shoji and T. Kawai, Kobunshi Kagaku (Chem. High Polymers), 28, 805 (1971).
A. Shoji and T. Kawai, Kobunshi Kagaku (Chem. High Polymers), 28, 809 (1971).
W. B. Gratzer and P. Doty, J. Am. Chem. Soc., 85, 1193 (1963).
H. E. Auer and P. Doty, Biochemistry, 5, 1708 (1966).
H. E. Auer and P. Doty, Biochemistry, 5, 1716 (1966).
R. T. Ingwall, H. A. Scheraga, N. Lotan, A. Berger, and E. Katchalski, Biopolymers, 6, 331 (1968).
T. Iio and S. Takahashi, Bull. Inst. Chem. Res., Kyoto Univ., 49, 80 (1971).
T. Iio, Biopolymers, 10, 1583 (1971).
E. M. Bradbury, P. D. Cary, and C. Crane-Robinson, Macromolecules, 5, 581 (1972).
E. R. Blout and R. H. Karlson, J. Am. Chem. Soc., 78, 941 (1956).
K. Nakagawa, N. Nishioka, A. Teramoto, and H. Fujita, Polym. J., 4, 332 (1973).
N. Nishioka, A. Teramoto, and H. Fujita, Polym. J., 8, 121 (1976).
T. Matsumoto, N. Nishioka, A. Teramoto, and H. Fujita, Macromolecules, 7, 824 (1974).
I. Omura, A. Teramoto, and H. Fujita, Macromolecules, 8, 284 (1975).
A. J. Bur, J. Chem. Phys., 52, 3813 (1970).
J. Y. Cassim and E. W. Taylor, Biophys. J., 5, 553 (1965).
J. Y. Cassim and E. W. Taylor, Biophys. J., 5, 573 (1965).
J. S. Franzen, J. B. Harry, and C. Bobik, Biopolymers, 5, 193 (1967).
T. Matsumoto and A. Teramoto, Biopolymers, 13, 1347 (1974).
P. Urnes and P. Doty, Adv. Protein Chem., 16, 401 (1961).
A. Wada, “Biopolymers (Seitai-Kobunshi),” Iwanami, Tokyo.
J. Applequist and T. G. Mahr, J. Am. Chem. Soc., 88, 5419 (1966).
T. Norisuye, Thesis, Osaka University, 1973.
A. Teramoto and H. Fujita, Adv. Polym. Sci., 18, 65 (1975).
A. Wada, J. Polym. Sci., 45, 145 (1960).
E. Marchal, C. Hornick, and H. Benoit, J. Chim. Phys. Physicochem. Biol., 64, 514 (1967).
E. Marchal and J. Marchal, J. Chim. Phys. Physicochem. Biol., 64, 1607 (1967).
H. Block, E. F. Hayes, and A. M. North, Trans. Faraday Soc., 66, 1095 (1970).
A. Wada and H. Kihara, Polym. J., 3, 482 (1972).
S. Saruta and Y. Einaga, unpublished data.
M. Tsuboi, J. Polym. Sci., 59, 139 (1962).
E. M. Bradbury, B. G. Carpenter, C. Crane-Robinson, and H. Goldman, Macromolecules, 4, 557 (1971).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Nishioka, N., Mishima, H. & Teramoto, A. Dielectric Dispersion of Polypeptide Solutions. III. Conformation and Dipole Moment of Copolypeptides of γ-Benzyl L-Glutamate and L-Alanine in m-Cresol. Polym J 9, 641–648 (1977). https://doi.org/10.1295/polymj.9.641
Issue Date:
DOI: https://doi.org/10.1295/polymj.9.641