Influence of Acylation on the Adsorption of Insulin to Hydrophobic Surfaces

• Published in: Pharmaceutical research Vol. 28; no. 5; pp. 1031 - 1040
• Main Authors: Pinholt, Charlotte, Hostrup, Susanne, Bukrinsky, Jens Thostrup, Frokjaer, Sven, Jorgensen, Lene
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.05.2011; Springer; Springer Nature B.V
• Subjects: Adsorption; Amino Acid Sequence; Biochemistry; Biological and medical sciences; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; General pharmacology; Humans; Hydrophobic and Hydrophilic Interactions; Insulin; Insulin - chemistry; Medical Law; Medical sciences; Molecular Sequence Data; Pharmaceutical sciences; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Pharmacology/Toxicology; Pharmacy; Proteins; Research Paper; Surface Properties; protein adsorption; CD; ITC; insulin; acylated insulin; Pharmaceutical technology; Adsorption; Insulin; Protein; Acylation
• ISSN: 0724-8741; 1573-904X
• DOI: 10.1007/s11095-010-0349-6

ABSTRACT Purpose To study the effect of acylation on the adsorption of insulin to hydrophobic polystyrene beads. Methods 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. Results 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. Conclusion 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.