Concentration Dependences of Macromolecular Sizes in Aqueous Solutions of Albumins

Abstract

On the basis of experimental data for the shear viscosity in the aqueous solutions of ovine serum albumin and using the cellular model describing the viscosity in aqueous solutions, the concentration dependences of the effective radius of ovine serum albumin macromolecules in the aqueous solutions within a concentration interval of 3.65–25.8 wt% and a temperature interval of 278–318 K at the constant pH = 7.05 are calculated. The concentration and temperature dependences of the effective radii of ovine, bovine, and human serum albumin macromolecules are compared. It is shown that they are partially similar for the solutions of ovine and human serum albumins within concentration intervals of 0.12–0.49 vol% and 0.18–0.48 vol%, respectively, provided an identical acid-base balance (pH) in those solutions. The following conclusions are drawn: (i) the concentration dependences of the effective radii of structurally similar macromolecules of various albumins are similar, but provided an identical pH, and (ii) the dependence of the volume concentration of aqueous albumin solutions on the temperature at the constant radius of a macromolecule confirms the hypothesis about the existence of a dynamic phase transition in aqueous solutions at a temperature of 42 ∘C, at which the thermal motion of water molecules significantly changes.

Вплив температури та тиску на термодинамічний коефіцієнт (∂V/∂T)p води

“…The data obtained using neutron methods [49] show that if the temperature grows and reaches a value of 315 K, the residence time of water molecules tends to zero in the framework of the Frenkel model; in other words, water loses its quasicrystalline character at this temperature. In a vicinity of the temperature 𝑇 = 315 K, the pH relaxation time in water is minimum [50,51]. Thus, the conclusion of this work about the peculiar temperature 𝑇 = 315 K for water is consistent with the results of studies of other water properties presented in the scientific literature.…”

Температурні Та Концентраційні Залежності Показника Кислотно-Лужного Балансу Водних Розчинів Хлориду Натрію При Розчиненні У Них Атмосферного Вуглекислого Газу

“…This pH value is less by one than pH(opt) = 7.35, which is typical of a healthy person. But this value is expectable as well, because all macromolecules of the albumin type [21][22][23][24], as well as acid additives, also affect the equilibrium pH values.…”

Звідна Та Незвідна Частини Водневого Показника РН Розбавлених Водних Розчинів Хлориду Натрію

“…The same temperature stabilization and measurement conditions were provided for all examined solutions. The peculiarities of the method used when measuring the pH in NaCl solutions contacting with atmospheric carbon dioxide were described in detail in works [3,4].…”

“…where pH(𝑇, 𝜁) are the experimental pH values obtained in works [3,4], and 𝜁 is the number of water molecules per NaCl ion. It was assumed that the pH values for the salt solution at the concentration 𝜁 0 = 1620 and pure water are practically identical.…”

“…still remains unanswered. In our recent work [3], we posed and answered the question about a close connection between the boundaries of the life activity for humans and many mammals and the corresponding pH values of their blood.…”