Arginine (Arg) is frequently used in biotechnology and pharmaceutics to stabilize protein preparations. When using charged ions like Arg, it is necessary to take into account their contribution to the increase in ionic strength, in addition to the effect of Arg on particular processes occurring under the conditions of constancy of ionic strength. Here, we examined contribution of ionic strength (0.15 and 0.5 M) to the effects of Arg on denaturation, thermal inactivation and aggregation of skeletal muscle glycogen phosphorylase b (Phb). Dynamic light scattering, analytical ultracentrifugation, differential scanning calorimetry, circular dichroism and enzymatic activity assay were used to assess the effects of Arg at constant ionic strength compared with the effects of ionic strength alone. We found that high ionic strength did not affect the secondary structure of Phb, but changed conformation of the protein. Such a destabilization of the enzyme causes an increase in the initial rate of aggregation and inactivation of Phb thereby affecting its denaturation. Binding of Arg causes additional changes in the protein conformation, weakening the bonds between monomers in the dimer. This causes the dimer to dissociate into monomers, which rapidly aggregate. Thus, Arg acts on these processes much stronger than just ionic strength.

精氨酸（Arg）通常用于生物技术和药物中以稳定蛋白质制品。当使用带电荷的离子（如Arg）时，除了Arg对离子强度恒定的条件下发生的特定过程的影响外，还必须考虑它们对离子强度增加的贡献。在这里，我们检查了离子强度（0.15和0.5 M）对Arg对骨骼肌糖原磷酸化酶b（Ph b的变性，热失活和聚集的影响）的贡献）。动态光散射，分析超速离心，差示扫描量热法，圆二色性和酶活性测定法用于评估在恒定离子强度下Arg与单独离子强度相比的效果。我们发现高离子强度不会影响Ph b的二级结构，但会改变蛋白质的构象。酶的这种不稳定会导致Ph b的初始聚集速率和失活速率增加从而影响其变性。Arg的结合会引起蛋白质构象的其他变化，从而削弱二聚体中单体之间的键。这导致二聚体解离成单体，其迅速聚集。因此，Arg对这些过程的作用比离子强度强得多。