Isolation from bovine haemoglobin of a peptide that might be used as a potential hydrophobic photosensitizer carrier

Abstract

The isolation of a peptic hydrolysate and of a pure peptide from bovine haemoglobin is described. These peptides were used to solubilize an insoluble photosensitizer in order to study their utilization as a carrier for photochemotherapy. Protoporphyrin IX was used as a model of an insoluble photosensitizer. Solubilization of protoporphyrin IX was first performed with the total haemoglobin hydrolysate, then with peptide fractions, and finally with a pure peptide isolated from this fraction by reversed-phase HPLC. The molecular mass and the primary structure of the pure peptide were determined by fast-atom-bombardment and tandem MS (molecular mass 1648 Da). The singlet oxygen quantum yield of the protoporphyrin IX-peptide complex was determined.