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Updated: Aug 16, 2026

A Rapid and Quantitative Fluorimetric Method for Protein-Targeting Small Molecule Drug Screening
Published on: October 16, 2015
Binding of propofol to human serum albumin
Michael Schywalsky1, Harald Ihmsen, Rainer Knoll
1Klinik für Anaesthesiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany. Michael.Schywalsky@kfa.imed.uni-erlangen.de
Abstract:
The binding properties of the short-acting hypnotic agent propofol (CAS 2078-54-8) to human serum albumin were studied in vitro. Using centrifugation through ultrafiltration membranes the ratio of free and bound propofol as a function of the human serum albumin concentration was determined. In addition, a biomathematical approach was tested that allowed the determination of the number of binding sites from the measured binding profile. At a total propofol concentration of 8.81 +/- 0.25 microg/mL the concentration of the free fraction of propofol ranged from 338 +/- 11 ng/mL (mean +/- SE) at an albumin concentration of 0.5% to 15 +/- 2 ng/ mL at an albumin concentration of 8.0%. The corresponding percentage of propofol binding ranged from 96.07 +/- 0.14% to 99.83 +/- 0.02%. From this binding profile the binding site was estimated to be n(0) = 2. The measured influence of the albumin concentration on propofol binding might be of relevance in states of hypo- or hyperalbuminaemia which could result in an altered demand of propofol.
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