Interaction of sodium decyl sulfate with poly(L‐ornithine) and poly(L‐lysine) in aqueous solution

Biopolymers - Tập 15 Số 11 - Trang 2263-2275 - 1976
Iwao Satake1, Jen Tsi Yang1
1Cardiovascular Research Institute and Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143

Tóm tắt

AbstractThe binding isotherms of sodium decyl sulfate to poly(L‐ornithine), poly(D,L‐ornithine), and poly(L‐lysine) at neutral pH were determined potentiometrically. The nature of a highly cooperative binding in all three cases suggests a micelle‐like clustering of the surfactant ions onto the polypeptide side groups. The hydrophobic interaction between the nonpolar groups overshadows the coulombic interaction between the charged groups. The titration curves can be interpreted well by the Zimm–Bragg theory. The average cluster size of bound surfactant ions is sufficiently large to promote the β‐structure of (L‐Lys)n even at a very low binding ratio of surfactant to polypeptide residue, whereas the onset of the helical structure for (L‐Orn)n begins after about 7 surfactant ions are bound to two turns of the helix. The CD results are consistent with this explanation.

Từ khóa


Tài liệu tham khảo

Steinhardt J., 1969, Multiple Equilibria in Proteins

10.1002/bip.1967.360050613

10.1073/pnas.55.4.981

10.1021/ja01029a058

10.1016/0006-291X(73)90783-3

Gavach C., 1969, Chim. Phys. Appl. Part. Ag. Surface (C. R. Congr. Int. Deterg. 5th 1968), 2, 859

10.1021/ja01058a002

10.1002/bip.360100504

10.1021/j100794a023

10.3891/acta.chem.scand.21-1767

Kaibara K., 1970, Mem. Fac. Sci. Kyushu Univ. Ser. C, 7, 1

Shinoda K., 1963, Colloidal Surfactants

10.1016/0021-9797(70)90144-X

10.1016/0021-9797(71)90284-0

10.1021/j150518a008

10.1063/1.1743393

10.1002/bip.1970.360090608

10.1063/1.1730390

10.1021/bi00844a020

Thông tin
Thông tin xuất bản

Biopolymers

Tập 15 Số 11

2263-2275

Thông tin tác giả