Fluorescence Red-edge-excitation Effects of Human Serum Albumin

We have studied the fluorescence red-edge-excitation effects of human serum albumin. Our results indicate that the red-edge-excitation effects of human serum albumin depend on the pH, temperature and concentration of the denaturant. The different red-edge-excitation effects are produced by a redistribution of the energy levels both in the ground and the exited states of the chromphore aroused by changes of external conditions. Studying red-edge-excitation effects of HAS, we have observed that under of acidic pH and high temperature the two denatured states of HAS have different conformations, and at pH 7.4 with increasing temperature there was a conformation transition process similar to that of acid denaturation.