Salt-specific effects in lysozyme solutions

• Дата: 2016
• Автори: Janc, T., Kastelic, M., Bončina, M., Vlachy, V.
• Формат: Стаття
• Мова: English
• Опубліковано: Інститут фізики конденсованих систем НАН України 2016
• Назва видання: Condensed Matter Physics
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/155805
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Salt-specific effects in lysozyme solutions / T. Janc, M. Kastelic, M. Bončina, V. Vlachy // Condensed Matter Physics. — 2016. — Т. 19, № 2. — С. 23601: 1–12. — Бібліогр.: 64 назв. — англ.

The effects of additions of low-molecular-mass salts on the properties of aqueous lysozyme solutions are examined by using the cloud-point temperature, Tcloud, measurements. Mixtures of protein, buffer, and simple salt in water are studied at pH=6.8 (phosphate buffer) and pH=4.6 (acetate buffer). We show that an addition of buffer in the amount above Ibuffer = 0.6 mol dm⁻³ does not affect the Tcloud values. However, by replacing a certain amount of the buffer electrolyte by another salt, keeping the total ionic strength constant, we can significantly change the cloud-point temperature. All the salts de-stabilize the solution and the magnitude of the effect depends on the nature of the salt. Experimental results are analyzed within the framework of the one-component model, which treats the protein-protein interaction as highly directional and of short-range. We use this approach to predict the second virial coefficients, and liquid-liquid phase diagrams under conditions, where Tcloud is determined experimentally.