A STUDY OF THE MOLECULAR SOURCES OF NONIDEAL OSMOTIC-PRESSURE OF BOVINE SERUM-ALBUMIN SOLUTIONS AS A FUNCTION OF PH
A STUDY OF THE MOLECULAR SOURCES OF NONIDEAL OSMOTIC-PRESSURE OF BOVINE SERUM-ALBUMIN SOLUTIONS AS A FUNCTION OF PH
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DOI：
10.1016/s0006-3495(94)80773-8
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发表时间：
1994-01-01
影响因子：
3.4
通讯作者：
CAMERON, IL
中科院分区：
文献类型：
--
作者：
KANAL, KM;FULLERTON, GD;CAMERON, IL
Scatchard及其同事对牛血清白蛋白（BSA）溶液的非理想渗透压进行了广泛的研究。pH值和盐依赖的非理想性变化的程度很大，无法解释。1992年，Fullerton等人推导出新的经验表达式来描述溶液的非理想依数性，包括渗透压（Fullerton等人，1992年）。70：1325-1331）。这些表达式是基于体积占有率和水化力的概念。用溶质/溶剂相互作用参数和“有效"渗透分子量A（e）精确描述非理想性。本文使用相互作用校正的非理想的渗透压表达式来计算BSA的水合/值和“有效"渗透分子量A（e），作为pH值的函数。由于BSA分子的变性，这两个因素以可预测的方式变化。两者都有助于增加渗透压相同的蛋白质浓度的溶液pH值远离等电点。增加的非理想性是由较大的溶剂可及表面积导致的较大的水合作用和由于变性（丝状）分子的节段运动导致的“有效"渗透分子量A（e）的降低引起的。
The nonideal osmotic pressure of bovine serum albumin (BSA) solutions was studied extensively by Scatchard and colleagues. The extent of pH- and salt-dependent nonideality changes are large and unexplained. In 1992, Fullerton et al. derived new empirical expressions to describe solution nonideal colligative properties including osmotic pressure (Fullerton et al. 1992. Biochem. Cell Biol. 70:1325-1331). These expressions are based on the concepts of volume occupancy and hydration force. Nonideality is accurately described by a solute/solvent interaction parameter land an ''effective'' osmotic molecular weight A(e). This paper uses the interaction-corrected nonideal expressions for osmotic pressure to calculate the hydration/values and ''effective'' osmotic molecular weight of BSA, A(e), as a function of pH. Both factors vary in a predictable manner due to denaturing of the BSA molecule. Both contribute to an increase in osmotic pressure for the same protein concentration as the solution pH moves away from the isoelectric point. Increased nonideality is caused by larger hydration resulting from larger solvent-accessible surface areas and by the decrease in ''effective'' osmotic molecular weight, A(e), due to segmental motion of denatured (filamentous) molecules.