A Comprehensive Spectroscopic Analysis of the Ibuprofen Binding with Human Serum Albumin, Part I.

Anna Ploch-Jankowska,Danuta Pentak

doi:10.3390/ph13090205

Anna Ploch-Jankowska, Danuta Pentak

Open Access

https://doi.org/10.3390/ph13090205

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Journal: Pharmaceuticals	Publication Date: Aug 21, 2020
Citations: 10	License type: CC BY 4.0

Affiliation: Medical University of Silesia, Opole University

Abstract

Human serum albumin (HSA) plays a fundamental role in the human body. It takes part in the transport of exogenic and endogenic substances, especially drugs. Ibuprofen (IBU) is one of the most commonly used non-steroidal anti-inflammatory drugs, used for pain relief, fever relief, and for anti-inflammatory purposes. The binding of ligands with HSA is a significant factor which determines the toxicity and the therapeutic dosages of these substances. The aim of this study was to compare the degree of ibuprofen binding with human serum albumin at various temperatures and protein solution pH values. In order to evaluate conformational changes in HSA caused by interaction with ibuprofen, spectrophotometric (first and second derivatives of the UV-VIS spectrum), and spectrofluorometric analyses were performed concerning the mutual interactions of IBU-HSA. The use of fluorescent spectroscopy allowed for recording fluorescent emissive spectra of HSA (5 × 10−6 mol/dm3) without and with the presence of ibuprofen (1 × 10−5–1 × 10−4 mol/dm3) at temperatures of 308, 310, 312, and 314 K at pH values of 6.5, 6.8, 7.4, 7.8, and 8.1. System fluorescence was excited by radiation of wavelengths of λex = 275 nm and λex = 295 nm. Based on this, original and modified Stern-Volmer, Scatchard, Klotz and Hill curves were determined. The data that were obtained showed a significant effect of temperature and pH of the human serum albumin solution on the strength and type of interaction of ibuprofen with HSA.

Highlights

Human serum albumin (HSA) is the most important blood serum protein, consisting of a single polypeptide chain of 585 amino acids [1,2,3,4]
Studies performed by Sudlow and Carter have proven the existence of specific sites in the HSA structure that bind to drugs—site I, called the warfarin binding site, site II called the benzodiazepine binding site as well as six ligand binding sites, which differ with respect to their structure [3,7,8]
Literature suggests that subtle changes in the protein tertiary structure, which are faintly visible on the zero-order absorption spectrum, become clear on the spectrum second derivative [27,28]

Summary

Introduction

Human serum albumin (HSA) is the most important blood serum protein, consisting of a single polypeptide chain of 585 amino acids [1,2,3,4]. Crystallographic structure analysis has shown that HSA consists of three structural domains (I–III). Each of these is made up of subdomains A and B [3,4]. Studies performed by Sudlow and Carter have proven the existence of specific sites in the HSA structure that bind to drugs—site I, called the warfarin binding site, site II called the benzodiazepine binding site as well as six ligand binding sites, which differ with respect to their structure [3,7,8]. It has been proven that drug binding sites I and II according to Sudlow correlate with subdomains IIA and IIIA [9]

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Conclusion