Ten new peptides with the amino acid sequences glycyl-X-Y-glycine and glycyl-X-Y-Z-glycine, where X, Y and Z are amino acids with neutral side-chains, have been synthesized and the partial molar volumes at infinite dilution, V2°, have been determined for all these peptides in aqueous solution at 298.15 K. For several of the peptides, V2° data have also been obtained over the temperature range 283.15 to 363.15 K using a scanning densimetric
method. The V2° results obtained are compared with those calculated using the principle of group additivity and the group partial molar volumes we have derived in earlier work. We have shown that our group partial
molar volumes can be used to reliably predict the partial molar volumes over a wide temperature
range of polypeptides that have neutral amino acid side-chains.
合成了十种
氨基酸序列为甘
氨酸-X-Y-甘
氨酸和甘
氨酸-X-Y-Z-甘
氨酸的肽,其中X、Y和Z是侧链为中性
氨基酸,并在298.15 K下测定了所有这些肽在
水溶液中的无限稀释部分摩尔体积V2°。对于几种肽,还通过扫描密度法在283.15到363.15 K的温度范围内获得了V2°数据。所得的V2°结果与我们在早期工作中推导出的群体部分摩尔体积和基于群体加法原理计算的值进行了比较。我们已经表明,我们的群体部分摩尔体积可以用于可靠地预测具有中性
氨基酸侧链的
多肽在较宽温度范围内的部分摩尔体积。