Detection Of Protein-ligand Interactions Research Articles

Detection of Protein-Ligand Interactions by 19F Nuclear Magnetic Resonance Using Hyperpolarized Water.

The transfer of nuclear spin hyperpolarization from water to ligand 19F spins results in a transient signal change that is indicative of protein-ligand interaction. The 19F nucleus allows for background-free detection of these signals, which are modulated by polarization transfer via pathways similar to those in a hyperpolarized 1H water LOGSY experiment. Quantification of the apparent heteronuclear cross-relaxation rates is facilitated by a simultaneous dual-channel detection of 1H and 19F signals. Calculated cross-relaxation rates for the 1H-19F transfer step indicate that these rates are sensitive to binding to medium- and large-sized proteins. The heteronuclear observation of hyperpolarization transfer from water may be used to screen protein-ligand interactions in drug discovery and other applications.

Anthraquinonyl glycoside facilitates the standardization of graphene electrodes for the impedance detection of lectins.

BackgroundConstruction of electrochemical impedance sensors by the self-assembly technique has become a promising strategy for the ‘label-free’ detection of protein-ligand interactions. However, previous impedance sensors are devoid of an inherent electrochemical signal, which limits the standardization of the sensors for protein recognition in a reproducible manner.ResultsWe designed and synthesized an anthraquinonyl glycoside (AG) where the anthraquinone (AQ) moiety can bind to the surface of a graphene-based working electrode while the glycoside serving as a ligand for lectin. By measuring the inherent voltammetric signal of AQ, the glycosides decorated on the working electrode could be simply quantified to obtain electrodes with a unified signal window. Subsequently, impedance analysis showed that the ‘standardized’ electrodes gave a reproducible electrochemical response to a selective lectin with no signal variation in the presence of unselective proteins.ConclusionAnthraquinone-modified ligands could be used to facilitate the standardization of electrochemical impedance sensors for the reproducible, selective analysis of ligand-protein interactions.Electronic supplementary materialThe online version of this article (doi:10.1186/s13065-014-0067-y) contains supplementary material, which is available to authorized users.

An investigation of small GTPases in relation to liver tumorigenesis using traditional Chinese medicine.

Recently, an important topic of liver tumorigenesis had been published in 2013. In this report, Ras and Rho had defined the relation of liver tumorigenesis. The traditional Chinese medicine (TCM) database has been screened for molecular compounds by simulating molecular docking and molecular dynamics to regulate Ras and liver tumorigenesis. Saussureamine C, S-allylmercaptocysteine, and Tryptophan are selected based on the highest docking score than other TCM compounds. The molecular dynamics are helpful in the analysis and detection of protein-ligand interactions. Based on the docking poses, hydrophobic interactions, and hydrogen bond variations, this research surmises are the main regions of important amino acids in Ras. In addition to the detection of TCM compound efficacy, we suggest Saussureamine C is better than the others for protein-ligand interaction.

Lead Screening for HIV of C-C Chemokine Receptor Type 5 Receptor Inhibited by Traditional Chinese Medicine.

The acquired immunodeficiency syndrome (AIDS), caused by the human immunodeficiency virus (HIV), has become a serious world-wide problem because of this disease's rapid propagation and incurability. Recent research has pointed out that the C-C chemokine receptor type 5 (CCR5) is an important target for HIV infection. The traditional Chinese medicine (TCM) database (http://tcm.cmu.edu.tw/) has been screened for molecular compounds that, by simulating molecular docking and molecular dynamics, may protect CCR5 against HIV. Saussureamine C, 5-hydroxy-L-tryptophan, and abrine are selected based on the docking score being higher than Maraviroc and other TCM compounds. The molecular dynamics are helpful in the analysis and detection of protein-ligand interactions. According to the docking poses, hydrophobic interactions, and hydrogen bond variations, this research surmises TRP86, TYR108, GLN194, TYR251, and GLU283 are the main regions of important amino acids in CCR5. In addition to the detection of TCM compound efficacy, we suggest saussureamine C is better than the others for maintaining protein composition during protein-ligand interaction, based on the structural variation.

Lead screening for HIV-1 integrase (IN) inhibited by traditional Chinese medicine.

Human immunodeficiency virus causes the acquired immunodeficiency syndrome (AIDS) and becomes a serious world-wide problem because of this disease's rapid propagation and incurability. Integrase strand transfer inhibitors (INSTIs) supports HIV have rapid drug resistance for antitreatment. Screening the traditional Chinese medicine (TCM) database by simulating molecular docking and molecular dynamics may select molecular compounds to inhibit INSTIs against HIV drug resistance. (S)-cathinone and (1S,2S)-norpseudoephedrine are selected based on structure and ligand-based drugs are designed and then get higher bioactivity predicted score from SVM than Raltegravir and other TCM compounds. The molecular dynamics are helpful in the analysis and detection of protein-ligand interactions. According to the docking poses, hydrophobic interactions and hydrogen bond variations define the main regions of important amino acids in integrase. In addition to the detection of TCM compound efficacy, we suggest (1S,2S)-norpseudoephedrine is better than the others based on the analysis of interaction and the effect on the structural variation.

Insight into HIV of IFN-induced myxovirus resistance 2 (MX2) expressed by traditional Chinese medicine.

Recently, an important topic of the acquired immunodeficiency syndrome (AIDS) had been published in 2013. In this report, the expression of the IFN-induced myxovirus resistance 2 (MX2) had been defined the function to kill the human immunodeficiency virus (HIV). The screening from the Traditional Chinese Medicine (TCM) database by simulating molecular docking and molecular dynamics could select candidate compounds, which may express MX2 against HIV. Saussureamine C, Crotalaburnine, and Precatorine are selected based on the highest docking score and other TCM compounds. The data from molecular dynamics are helpful in the analysis and detection of protein-ligand interactions. According to the docking poses, hydrophobic interactions, and hydrogen bond with structure variations, this research could assess the interaction between protein and ligand interaction. In addition to the detection of TCM compound efficacy, we suggest that Saussureamine C is better than the others in protein-ligand interaction and the structural variation to express MX2.

Lead screening for CXCR4 of the human HIV infection receptor inhibited by traditional Chinese medicine.

The acquired immunodeficiency syndrome (AIDS) is a serious worldwide disease caused by the human immunodeficiency virus (HIV) infection. Recent research has pointed out that the G protein-coupled chemokine receptor CXCR4 and the coreceptor C-C chemokine receptor type 5 (CCR5) are important targets for HIV infection. The traditional Chinese medicine (TCM) database has been screened for candidate compounds by simulating molecular docking and molecular dynamics against HIV. Saussureamine C, 5-hydroxy-L-tryptophan, and diiodotyrosine are selected based on the highest docking score. The molecular dynamics is helpful in the analysis and detection of protein-ligand interactions. According to the analysis of docking poses, hydrophobic interactions, hydrogen bond variations, and the comparison of the effect on CXCR4 and CCR5, these results indicate Saussureamine C may have better effect on these two receptors. But for some considerations, diiodotyrosine could make the largest variation and may have some efficacy contrary to expectations.