Morphological analysis and interaction of chlorophyll and BSA.

Filipe D S Gorza,Graciela C Pedro,Romário J Da Silva,Nara C De Souza,Tarquin F Trescher,Josmary R Silva

doi:10.1155/2014/872701

Filipe D S Gorza, Graciela C Pedro + Show 4 more

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https://doi.org/10.1155/2014/872701

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Abstract

Interactions between proteins and drugs, which can lead to formation of stable drug-protein complexes, have important implications on several processes related to human health. These interactions can affect, for instance, free concentration, biological activity, and metabolism of the drugs in the blood stream. Here, we report on the UV-Visible spectroscopic investigation on the interaction of bovine serum albumin (BSA) with chlorophyll (Chl) in aqueous solution under physiological conditions. Binding constants at different temperatures—obtained by using the Benesi-Hildebrand equation—were found to be of the same order of magnitude (~104 M−1) indicating low affinity of Chl with BSA. We have found a hyperchromism, which suggested an interaction between BSA and Chl occurring through conformational changes of BSA caused by exposition of tryptophan to solvent. Films from BSA and Chl obtained at different Chl concentrations showed fractal structures, which were characterized by fractal dimension calculated from microscopic image analysis.

Highlights

Binding of human serum protein (HSA) with different compounds has been an intense research field in chemistry, biology, and medicine
We report on the study of interaction between Chl and bovine serum albumin (BSA) in aqueous solution by using UVVis spectroscopy, which allowed the determining of the binding constants at different temperatures
In contrast to Chl in solution (404 nm), the absorption peak of Chl films appears at 408 nm. These results reveal a red shift of 4 nm for the film in relation to aqueous solution

Summary

Introduction

Binding of human serum protein (HSA) with different compounds has been an intense research field in chemistry, biology, and medicine. The behavior of the binding of chlorophyll (Chl) to BSA has been examined [22] because it has been shown that this ligand can exhibit antimutagenic property against several potential human carcinogens [23, 24], action antioxidant [25], and antigenotoxic [26] It is considered as a drug due to its bactericidal activity and high performance healing of wounds in addition to acting as an antioxidant in burns [27]. It has been used as a photosensitizer for photodynamic therapy drug for its high absorptivity in the visible light region of the electromagnetic spectrum and low toxicity Despite these studies, interaction of BSA and Chl by analysis of casting films from these compounds has not been carried out yet.

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