Department of Pharmaceutics and Analytical Chemistry Faculty of Pharmaceutical Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark.
Pharm Res. 2011 May;28(5):1031-40. doi: 10.1007/s11095-010-0349-6. Epub 2010 Dec 29.
To study the effect of acylation on the adsorption of insulin to hydrophobic polystyrene beads.
Adsorption isotherms for adsorption of insulin and acylated insulin to hydrophobic polystyrene beads were established, and the adsorption of the two proteins was compared further with isothermal titration calorimetry. In addition, the secondary structure and the association behavior of the two proteins were studied with circular dichroism.
Insulin and acylated insulin adsorbed with high affinity to the hydrophobic polystyrene beads. More acylated insulin molecules than insulin molecules adsorbed per unit surface area from solutions containing monomer-dimer mixtures of acylated insulin and insulin, respectively. In contrast, no difference was observed in the number of insulin and acylated insulin molecules adsorbing per unit surface area, when adsorption occurred from solutions containing monomer-dimer-hexamer mixtures.
The influence of acylation on the adsorption behavior of insulin depends on the association degree of insulin, possibly due to a greater difference in hydrophobicity between monomeric insulin and acylated insulin than between the hexameric forms of these two proteins.
研究酰化对胰岛素向疏水性聚苯乙烯珠吸附的影响。
建立了胰岛素和酰化胰岛素吸附到疏水性聚苯乙烯珠的吸附等温线，并进一步通过等温滴定量热法比较了两种蛋白质的吸附。此外，还使用圆二色性研究了两种蛋白质的二级结构和聚集行为。
胰岛素和酰化胰岛素以高亲和力吸附到疏水性聚苯乙烯珠上。与胰岛素单体-二聚体混合物溶液相比，分别从含有酰化胰岛素和胰岛素单体-二聚体混合物的溶液中，单位表面积吸附的酰化胰岛素分子数多于胰岛素分子数。相比之下，当吸附发生在含有胰岛素单体-二聚体-六聚体混合物的溶液中时，单位表面积吸附的胰岛素和酰化胰岛素分子数没有差异。
酰化对胰岛素吸附行为的影响取决于胰岛素的缔合程度，这可能是由于单体胰岛素和酰化胰岛素之间的疏水性差异大于这两种蛋白质六聚体形式之间的疏水性差异。
