Abstract Apparent molar volumes, VΦ, and apparent molar isentropic compressions, KS,Φ, of the protein stabilizer, trimethylamine-N-oxide (TMAO) were determined from the densities and speed of sound measured at T = (288.15, 298.15 and 308.15) K in aqueous solutions of N-methylacetamide (NMA) at four different concentrations (2, 4, 6 and 8 mol/kg). The concentration dependencies of the calculated quantities extrapolated to the infinite dilution lead to the standard partial molar properties. The latter values were combined with the previously published data for TMAO in pure water, to obtain the partial molar properties of transfer from water to aqueous NMA solutions. From the transfer data the interaction parameters were determined according to the McMillan-Mayer theory formalism. The calculated parameters and their temperature characteristics are discussed in terms of solute-solvent, solute-solute and solute-cosolute interactions and compared with analogous data for protein denaturant, n-butylurea.

中文翻译：

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蛋白质稳定剂三甲胺-N-氧化物在 N-甲基乙酰胺水溶液中的水合特性——288.15 和 308.15K 之间的体积和压缩性研究

摘要 蛋白质稳定剂三甲胺-N-氧化物 (TMAO) 的表观摩尔体积 VΦ 和表观摩尔等熵压缩 KS,Φ 由在 T = (288.15、298.15 和 308.15) 处测量的密度和声速确定K 在四种不同浓度（2、4、6 和 8 mol/kg）的 N-甲基乙酰胺 (NMA) 水溶液中。外推到无限稀释的计算量的浓度依赖性导致标准偏摩尔特性。后一个值与之前公布的纯水中 TMAO 数据相结合，以获得从水转移到 NMA 水溶液的偏摩尔特性。从转移数据中，根据 McMillan-Mayer 理论形式确定相互作用参数。