Abstract
High-performance affinity microcolumns were used to characterize binding by the anti-diabetic drugs repaglinide and nateglinide with normal and glycated forms of human serum albumin. The microcolumns contained only nmol amounts of protein and provided a detailed analysis of these drug interactions with good precision and in a matter of minutes per experiment. The overall binding by repaglinide to normal and glycated albumin fits a model with two types of binding sites: a set of one or two moderate-to-high affinity regions and a larger set of weaker regions with association equilibrium constants of ∼105 and 103 M−1, respectively, at pH 7.4 and 37°C. Competition studies gave site-specific association constants for repaglinide and nateglinide at Sudlow site I of 4.2 × 104 and 5.0 × 104 M−1 for normal albumin, with a decrease of 26%–30% being seen for nateglinide with glycated albumin and no significant change being noted for repaglinide. At Sudlow site II, repaglinide and nateglinide had association constants for normal albumin of 6.1 × 104 and 7.1 × 105 M−1, with glycated albumin giving an increase in the association constant at this site for repaglinide of 1.6- to 1.8-fold and a decrease for nateglinide of 51%–58%.
Original language | English (US) |
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Pages (from-to) | 4176-4186 |
Number of pages | 11 |
Journal | Journal of Separation Science |
Volume | 45 |
Issue number | 23 |
DOIs | |
State | Published - Dec 2022 |
Keywords
- drug-protein binding
- glycation
- high-performance affinity microcolumn
- human serum albumin
- meglitinide
ASJC Scopus subject areas
- Analytical Chemistry
- Filtration and Separation