Arakawa T, Kita Y, Carpenter J F
Amgen Inc., Amgen Center, Thousand Oaks, California 91320.
Pharm Res. 1991 Mar;8(3):285-91. doi: 10.1023/a:1015825027737.
The stability of proteins is affected by a variety of solvent additives. Sugars, certain amino acids and salts, and polyhydric alcohols stabilize proteins in solution and during freeze-thawing. Urea and guanidine hydrochloride destabilize proteins under either condition. These effects can be explained from the preferential interactions of the cosolvents with the proteins; i.e., the protein stabilizers are preferentially excluded from the proteins, while the destabilizers bind to them. There is a class of compounds, such as polyethylene glycol and 2-methyl-2,4-pentanediol, that destabilize proteins at high temperature but stabilize them during freeze-thawing. Such effects can be accounted for by their preferential exclusion from the native proteins determined at room temperature and from their hydrophobic character, which depends on temperature. During freeze-drying, only a few sugars appear to be effective in protecting proteins from inactivation, as most other stabilizers cannot exert their action on proteins without water. The stabilization is due to hydrogen bonding between the sugars and the dried proteins, the sugars acting as water substitute. Understanding the mechanism of the effects of solvent additives on the protein stability should aid in the development of a suitable formulation for protein.
蛋白质的稳定性受多种溶剂添加剂的影响。糖类、某些氨基酸和盐以及多元醇可在溶液中及冻融过程中使蛋白质稳定。尿素和盐酸胍在任何一种情况下都会使蛋白质不稳定。这些效应可以从共溶剂与蛋白质的优先相互作用来解释；也就是说，蛋白质稳定剂优先被排除在蛋白质之外，而变性剂则与它们结合。有一类化合物，如聚乙二醇和2-甲基-2,4-戊二醇，在高温下会使蛋白质不稳定，但在冻融过程中会使它们稳定。这种效应可以通过它们在室温下从天然蛋白质中的优先排除以及它们取决于温度的疏水特性来解释。在冷冻干燥过程中，似乎只有少数糖类能有效保护蛋白质不被灭活，因为大多数其他稳定剂在没有水的情况下无法对蛋白质发挥作用。这种稳定作用是由于糖类与干燥蛋白质之间的氢键，糖类起到了水替代物的作用。了解溶剂添加剂对蛋白质稳定性影响的机制应有助于开发适合蛋白质的制剂。
