2D FTIR gives new information about the pressure effect on the structure and dynamics of macromolecular systems, Application of this analysis to proteins can unravel the relation of conformational changes and H/D exchange processes. For lipoxygenase; a pressure of 6.5 kbar induces irreversible conformational changes resulting in an increased exposure of interior parts of the protein to the solvent. At the transition pressure the spectral changes indicate a correlation between conformational changes and H/D exchange. Below and above this pressure, the effects of H/D exchange on the spectral changes are predominant. (C) 2000 Elsevier Science B.V. All rights reserved.