Protein Target Prediction and Validation of Small Molecule Compound

Summary

The experiment used here shows a method of molecular docking combined with cellular thermal shift assay to predict and validate the interaction between small molecules and protein targets.

Abstract

Proteins are fundamental to human physiology, with their targets being crucial in research and drug development. The identification and validation of crucial protein targets have become integral to drug development. Molecular docking is a computational tool widely utilized to investigate protein-ligand binding, especially in the context of drug and protein target interactions. For the experimental verification of the binding and to access the binding of the drug and its target directly, the cellular thermal shift assay (CETSA) method is used. This study aimed to integrate molecular docking with CETSA to predict and validate interactions between drugs and vital protein targets. Specifically, we predicted the interaction between xanthatin and Keap1 protein as well as its binding mode through molecular docking analysis, followed by verification of the interaction using the CETSA assay. Our results demonstrated that xanthatin could establish hydrogen bonds with specific amino acid residues of Keap1 protein and reduce the thermostability of Keap1 protein, indicating that xanthatin could directly interact with Keap1 protein.

Introduction

Proteins are highly important macromolecules in living organisms and possess a diverse range of unique functions within cells, such as membrane composition, cytoskeleton formation, enzyme activity, transportation, cell signaling, and involvement in both intracellular and extracellular mechanisms^1,2,3. Proteins manifest their biological functions primarily through specific interactions with a variety of molecules, including other proteins, nucleic acids, small molecule ligands, and metal ions^1,4. Ligands are small mole....

Protocol

1. Downloading the structures of xanthatin and Keap1

1. Open the PubChem database (https://pubchem.ncbi.nlm.nih.gov/), input xanthatin (small molecule), then press Search and click on The First Result. Click on Download and click Save under 2D structure to save the compound in .sdf format.
2. Download the crystal structure of the protein.
   1. Open the UniProt database (https://www.uniprot.org/), input Keap1 a.......

Discussion

The identification of disease targets and the discovery and development of drugs are closely interconnected²⁷. By precisely targeting specific targets, drug candidates can be developed to treat particular diseases more effectively while concurrently minimizing the side effects associated with the drugs^28,29. The most commonly used targets are protein targets³⁰. However, the identification of special protein targets .......

Materials

Name	Company	Catalog Number	Comments
0.45 μm Polyvinylidene fluoride membrane	Millipore	PR05509
Anhydrous ethanol	Chron chemicals	64-17-5
Bovine serum albumin	BioFroxx	4240GR100
Broad-spectrum protease inhibitor mixtures	Boster Biological Technology Co., Ltd	AR1193
DMSO	Boster Biological Technology Co., Ltd	PYG0040
Enhanced chemiluminescence reagent	Beyotime Biotechnology Co., Ltd	P0018S
GAPDH antibody	ProteinTech Group Co., Ltd	10494-1-AP
Gel Imaging Instrument	E-BLOT	Touch Imager Pro
Gradient PCR instrument	Biometra TADVANCED	Biometra Tadvanced 96SG
High-speed freezing centrifuge	Beckman Coulter	Allegra X-30R
Horseradish peroxidase-conjugated affiniPure goat antibody	ProteinTech Group Co., Ltd	SA00001-2
Isopropyl alcohol	Chron chemicals	67-63-0
Keap1 antibody	Zen BioScience Co., Ltd	R26935
Metal bath	Analytik Jena	TSC
Methanol	Chron chemicals	67-56-1
Ncmblot rapid transfer buffer (20×)	NCM Biotech Co., Ltd	WB4600
Omni-Easy OneStep PAGE gel fast preparation kie	Epizyme Biotech Co., Ltd	PG212
Phosphate buffer saline	Boster Biological Technology Co., Ltd	PYG0021
Prestained Color Protein Marker	Biosharp	BL741A
Protein Blotting Electrophoresis System	Bio-Rad	MiniPROTEANÒTetra Cell
RAW264.7 cell	Beyotime Biotechnology Co., Ltd	C7505
RAW264.7 cell-specific medium	Procell Life Science&Technology Co., Ltd	CM-0597
SDS-PAGE protein loading buffer	Boster Biological Technology Co., Ltd	AR1112-10
SDS-PAGE running buffer powder	Servicebio	G2018
Tris buffered saline powder	Servicebio	G0001
Tween 20	BioFroxx	1247ML100
Water bath	Memmert	WNE10
Water purifier	Millipore	Milli- IQ 7005
Xanthatin	ChemConst Biotechnology Co., Ltd	CONST210706