title: [Methodology of electrospray ion trap mass spectrometry for analyzing the non-covalent binding of protein and low-molecular-weight ligand].
abstract: A new MS-titration method for the non-covalent binding of protein-ligand based on the research of berberine and alpha1-acid glycoprotein was established. The major presumption of new method is that the total concentration of protein-ligand complex is approximately the same as the total concentration of acting protein if a certain extent of affinity is existed between protein and ligand, in addition, the mole amount of acting ligand is more than that of acting protein. The non-covalent binding behaviours between berberine and alpha1-acid glycoprotein was studied by using electrospray ionization ion trap mass spectrometry (ESI-ITMS) , and the results were verified by fluorescence quenching method. The results showed that the binding behaviours between berberine and alpha1-acid glycoprotein, for example, stability constant, number of binding site, type of the main binding force, were almost the same by using the new MS-titration method and fluorescence quenching method. Comparing with the reported MS-titration method, the presented MS-titration method in this paper is more simple and applicable, does not demand much for the devices, and can lead to reliable results in same cases.
authors.affiliation: Hubei Provincal Key Lab of Bio-Technology of Traditional Chinese Medicine, Hubei University, Wuhan 430062, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cao
authors.forename: Feng-mei
authors.initials: FM
authors.lastname: Han
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
mesh_terms: D001599:Berberine / Q000378:metabolism*; D008024:Ligands; D009961:Orosomucoid / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods*; D011506:Proteins / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D008024:Ligands; D009961:Orosomucoid; D011506:Proteins; D001599:Berberine