Fundermental study of lysozyme crystallization at high pressure

首先，我们使用氯化铵和氯化铯作为溶质，对用于溶解度测量的高压系统进行了高达300兆帕的测试。溶解度的重现性为（]SY+-[）0.5%。另一方面，研究了在0.1 MPa下溶菌酶溶解度的测定条件。得到以下结果。(1)溶解度测定中溶菌酶的固态取决于溶质的初始浓度。这意味着溶菌酶的样品溶液应在低浓度下制备。(2)达到饱和的震动时间很长。虽然氯化铯和氯化铵最多需要一到两天的时间，但需要几周的时间。然后在高达200mpa的高压下检查溶解度。结果表明：(1)随着压力的增加，沉淀速率降低；(2)溶解度增加，从0.1 MPa时的7 mg/ml增加到200 MPa时的20 mg/ml。

First our high pressure system for the solubility measurement was checked up to 300 MPa using ammonium chloride and cesium chloride as solutes. The reproducibility of the solubility was (]SY+-[)0.5%. On the other hand, conditions of the solubility measurement of lysozyme were surveyed at 0.1 MPa. and get following results. (1) The solid state of lysozyme in the solubility measurement depends on the initial concentration of the solute. It means that sample solution of lysozyme should be prepared at low concentration. (2) Shaking time to attain to the saturation is very long. It takes several weeks though those for CsCl and NH4Cl are at most one or two days.Next the solubility was checked at high pressure up to 200 MPa. It is found that (1) rate of the precipitaion decreased with increasing pressure and (2) the solubility increased, i.e., 7 mg/ml at 0.1 MPa to 20 mg/ml at 200 MPa.