| abstract |
A method is disclosed for identifying or analyzing,neasily and in a short time, the molecular weight, thenchemical species of molecules, and the structure ofnmolecules, of a protein present on the superficial layer ofncells or in cells, or a substance interacting with thenprotein. This method comprises the steps of: bringing thencells having the protein and the substance interacting withnthe protein into contact with each other to cause thensubstance to interact with the cells; purifying the cells,nwith the cells and the substance in an interacting state;nirradiating the purified cells with a laser to ionize thensubstance directly; and analyzing the ionized substance bynmass spectrometry. n This method is a new method for screening ansubstance interacting with a protein present in cells, andna new method for determining the presence of a particularnprotein in cells with the use of a substance interactingnwith the protein, the new methods not relying onnconventional bioassays. These methods are easy to operatenand capable of accurate and prompt determination. |