Oxidized Raffinose Intramolecular Cross-linking of Porcine Hemoglobin Effects on Its Structure and Function

Periodate-oxidized raffinose is utilized to modify porcine oxyhemoglobin and deoxyhemoglobin, respectively. These modified protein derivatives showed special characteristics that it can resist the dissociation of alpha(2)beta(2) tetramer in comparison with natural proteins. According to the analysis in SDS-PAGE and reverse phase HPLC, the two porcine hemoglobin derivatives are all intramolecular linked proteins and the cross-linking sites lie between the two beta subunits. No eminent differences were found in the UV-VIS absorption spectrum between natural and modified proteins. However, after calibration for protein concentration, the emission of modified porcine deoxyhemoglobin is much weaker than the modified oxyhemoglobin and the natural protein. Furthermore, the porcine hemoglobin derivatives' characteristics of the oxygen affinity and Auto-oxidized rate also show significant differences with natural protein. The possible application of these porcine hemoglobin derivatives in the preparation of hemoglobin-based blood substitutes is discussed.