Abstract
Quasi-elastic light scattering studies were performed on purified bovine serum albumin sample under conditions of high and low ionic strength and pH. Two relaxation modes were observed in all cases. The apparent diffusion coefficient obtained in the asymptotic time window (T) limit T leads to 0-i.e., Dapp(T leads to 0)-was found to be approximately equal to 6.1 X 10(-7) cm2/sec under conditions that minimized electrical forces (100 mM KCl at pH 4.5). As the ionic strength was lowered to 0.1 mM KCl (pH 4.5) or the pH was raised to 10 (100 mM KCl), Dapp(T leads to 0) increased to 7.2-7.5 X 10(-7) cm2/sec. These observations for Dapp(T leads to 0) are interpretable in terms of small-ion-polyion coupled modes in accordance with the theory of Lin et al. regarding dynamic Donnan effects [Lin, S.-C., Lee, W. I. & Schurr, J. M. (1978) Biopolymers 17, 1041-1064] without having to invoke direct polyion-polyion interactions. These direct interactions may be important at extreme ionic strength and pH conditions (0.1 mM KCl at pH 10). Concomitant with an increase in Dapp(T leads to 0), under appropriate changes in solvent conditions, is an increase in the relative amplitude and relaxation time of the slow decay mode.
Full text
PDF
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Fulmer A. W., Benbasat J. A., Bloomfield V. A. Ionic strength effects on macroion diffusion and excess light-scattering intensities of short DNA rods. Biopolymers. 1981 Jun;20(6):1147–1159. doi: 10.1002/bip.1981.360200606. [DOI] [PubMed] [Google Scholar]
- Hanss M., Bernengo J. C. Dielectric relaxation and orientation of DNA molecules. Biopolymers. 1973;12(9):2151–2159. doi: 10.1002/bip.1973.360120918. [DOI] [PubMed] [Google Scholar]
- Imai N., Sasaki S. Dielectric increment in polyion solutions due to the distortion of counterion distribution. Biophys Chem. 1980 Jun;11(3-4):361–367. doi: 10.1016/0301-4622(80)87009-8. [DOI] [PubMed] [Google Scholar]
- Kirkwood J. G., Shumaker J. B. Forces between Protein Molecules in Solution Arising from Fluctuations in Proton Charge and Configuration. Proc Natl Acad Sci U S A. 1952 Oct;38(10):863–871. doi: 10.1073/pnas.38.10.863. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kirkwood J. G., Shumaker J. B. The Influence of Dipole Moment Fluctuations on the Dielectric Increment of Proteins in Solution. Proc Natl Acad Sci U S A. 1952 Oct;38(10):855–862. doi: 10.1073/pnas.38.10.855. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Raj T., Flygare W. H. Diffusion studies of bovine serum albumin by quasielastic light scattering. Biochemistry. 1974 Jul 30;13(16):3336–3340. doi: 10.1021/bi00713a024. [DOI] [PubMed] [Google Scholar]
- Sakamoto M., Kanda H., Hayakawa R., Wada Y. Dielectric relaxation of DNA in aqueous solutions. Biopolymers. 1976 May;15(5):879–892. doi: 10.1002/bip.1976.360150506. [DOI] [PubMed] [Google Scholar]
- Schmitz K. S., Parthasarathy N., Kent J. C., Gauntt J. Quasielastic light scattering by biopolymers. V. Interparticle interactions between polynucleosomes. Biopolymers. 1982 Jul;21(7):1365–1382. doi: 10.1002/bip.360210707. [DOI] [PubMed] [Google Scholar]
- Schmitz K. S. Quasielastic light scattering by biopolymers. VI. Diffusion of mononucleosomes and oligonucleosomes in the presence of static and sinusoidal electric fields. Biopolymers. 1982 Jul;21(7):1383–1398. doi: 10.1002/bip.360210708. [DOI] [PubMed] [Google Scholar]
- Takashima S. Effect of ions on the dielectric relaxation of DNA. Biopolymers. 1967;5(10):899–913. doi: 10.1002/bip.1967.360051004. [DOI] [PubMed] [Google Scholar]