UV-VIS Absorption Spectra at High Pressure of C-Phycocyanin and Allophycocyanin from Mastigocladus laminosus

Abstract

The behaviour of monomers and trimers of C-phycocyanin and allophycocyanin under high pressure is studied by UV-VIS absorption spectroscopy. It is found that fast variations of pressure (Ap ≳ 500 bar) and/or temperature are accompanied by significant changes in the absorption spectra (intensity and/or spectral shift). The induced differences disappear, however, in part, when the samples are left for several minutes at the final pressure (relaxation effect). The observed spectral variations are different from those connected with a change in state of aggregation and could therefore be due to small modifications of the chromophore-protein arrange-ment. © 1991, Walter de Gruyter. All rights reserved.