Study of the Interaction of Indirubin with Bovine Serum Albumin

Abstract

Indirubin (2H-indol-2-one, 3-(1,3-dihydro-3-oxo-2H-indol-2-ylidene)-1,3-dilydro) constitutes the main active ingredient of a traditional Chinese medicinal recipe, Danggui Longhui Wan, used to treat various diseases including chronic myelocytic leukemia. 1,2) Indirubin is an inhibitor of cyclin dependent kinases and glycogen synthase kinase. [3][4][5] Indirubin has been recently discovered to be a potent ligand of the aryl hydrocarbon receptor (AhR), also known as the "dioxin receptor".6) Recent studies also showed that indirubin inhibits 2,4,6-trinitro-1-chlorobenzene (TNBC)-induced inflammatory reactions in mice. 7)Bovine serum albumin (BSA) is a single-chain 582 amino acid globular nonglycoprotein cross-linked with 17 cystine residues (8 disulfide bonds and 1 free thiol). As one of the most abundant proteins, BSA plays an important role in the transport and deposition of a variety of endogenous and exogenous ligands in blood. BSA is divided into three linearly arranged, structurally distinct, and evolutionarily related domains (I-III) [8][9][10][11] ; each domain is composed of two subdomains (A, B). BSA has two tryptophans embedded in two different domains, one is Trp-134, located in the proximity of the protein surface, but buried in a hydrophobic pocket of domain I, the other is Trp-214, located in an internal part of domain II.12) BSA has a wide range of physiological functions involving the binding, transport, and delivery of fatty acids, bilirubin, porphyrins, thyroxine, tryptophan and steroids. [8][9][10][11] It is home to specific binding sites for metals, pharmaceuticals, and dyes. The binding ability on the interaction of drug with protein will significantly affect the apparent distribution volume of the drugs and also affect the elimination rate of drugs in most cases; so the studies on this aspect become an important research field in life sciences, chemistry and clinical medicine because it can provide important information on the structural features which determine the therapeutic effectiveness of drugs.Serial study methods concerning the interaction between drugs and protein include NMR, 13) CD, 14) ROD, 15) Raman 16) attenuated total reflectance-Fourier transform infrared (ATR-FTIR), UV-Vis absorbance and fluorescence spectroscopy. Fluorescence quenching techniques are great aids in the study of binding of drugs to plasma proteins and serum albumin in particular because of their high sensitivity, rapidity and ease of implementation. FT-IR spectroscopy has recently become very popular for the structural characterization of proteins. The most important advantage of FT-IR spectroscopy for biological studies is that the spectra of almost any biological system can be obtained in a wide variety of environments. For secondary-structure analysis of proteins, so far, many studies have been carried out to investigate the interaction of proteins with drugs. However, the information on the indirubin-BSA binding mode, the binding constant, and the effects of indirubin complexation on the protein secondary s...

Miltefosine loaded albumin microparticles for treatment of visceral leishmaniasis: formulation development and in vitro evaluation

“…6A, the characteristic peaks of MF at 1473 cm −1 (CH 2 bending) and 1246 cm −1 (PO asymmetric stretching) and overlap of 1081 cm −1 (PO symmetric stretching) and 1068 cm −1 (POC stretching) were observed in the MF loaded albumin microspheres. In spectra of albumin it is reporter that protein amide‐I in the region 1600–1700 cm −1 (mainly CO stretch) and amide‐II band ∼1548 cm −1 (CN stretch coupled with NH bending mode) both have a relationship with the secondary structure of protein, and amide‐I band is more sensitive to the change of protein secondary structure than amide‐II 20. The characteristic amide band‐I at 1658.53 cm −1 and amide band‐II at 1542.70 cm −1 of albumin in blank microspheres were present in the drug loaded microspheres and there was an insignificant difference in amide I band (from 1658.53 to 1659.39 cm −1 ) and the amide II band (from 1542.70 to 1542.93 cm −1 ) which indicated that there was no covalent kind of interaction.…”

Interaction of Bioactive Components Caffeoylquinic Acid Derivatives in Chinese Medicines with Bovine Serum Albumin

“…38) In order to determine the specificity of the CQAs binding and the location of the CQAs-binding sites on BSA, the displacement experiments were carried out according to the literatures, 22,39) using some drugs mentioned above. A 3.0 ml solution of BSA with an appropriate CQAs concentration was titrated by successive addition of warfarin and ibuprofen solutions, respectively.…”

“…This method can reveal the accessibility of quenchers to fluorophore groups in the protein, provide an understanding of binding mechanisms to drugs, and yield clues to the chemistry of the binding phenomenon. The binding of various bioactive components in Chinese medicines to serum albumins have been investigated widely, [22][23][24][25][26] including chlorogenic acid, 27,28) but the interactions between dicaffeoylquinic acid derivatives and serum albumins have not been reported.…”

Indirubin-pregnane X receptor-JNK axis accelerates skin wound healing

“…In addition to nutritional uptake from herbs and vegetables, indirubin is also biosynthesized from tryptophan by commensal microbiota such as Escherichia coli in the intestine and Malassezia yeast in the skin 15,40,41 . Evidence has suggested that the intestinal indirubin is absorbed into the blood, binds to serum albumin, circulates throughout the body, and is excreted into the urine 10,42,43 . This circulating indirubin exerts the biological function of activating the AHR pathway, among other potential functions 10 .…”