Patent ID: 6730485
Filing Date: 2004-05-04
Classification: C12Q,G01N

Abstract:
A method for testing whether a predetermined position in a target molecule is at or proximate to a ligand binding site in said target molecule comprising:(a) contacting a ligand with said target molecule under conditions that allow formation of a complex between said target molecule and said ligand; (b) contacting said ligand with a test molecule under conditions that allow formation of a complex between said test molecule and said ligand, wherein said test molecule is said target molecule comprising a modification at a predetermined position, wherein said modification is capable of modulating ligand binding affinity when said modification is located at or proximate to said ligand binding site in said target molecule; (c) comparing the relative amount of target molecule-ligand complex to the relative amount of test molecule-ligand complex using a mass spectrometer; and (d) determining whether said predetermined position in said target molecule is at or proximate to said ligand binding site, wherein a difference in the relative amounts of target molecule-ligand complex and test molecule-ligand complex indicates that said ligand binds at or proximate to said predetermined position in said target molecule.