Zinc Substituted Myoglobin−Albumin Fusion Protein: A Photosensitizer for Cancer Therapy

Abstract

AbstractMyoglobin combined with human serum albumin (Mb‐HSA) can be produced using yeast Pichia pastoris as a host strain, with secretion into the culture medium. This Mb‐HSA fusion protein possesses identical O2 binding affinity to that of naked Mb. The Mb unit is reconstituted with a zinc(II) protoporphyrin IX, yielding (zinc substituted Mb)‐HSA, ZnMb‐HSA. The photophysical property and singlet O2 generation ability of ZnMb‐HSA are equivalent to those of ZnMb. In vitro cell experiments revealed that ZnMb‐HSA acts as a superior photosensitizer for photodynamic cancer therapy. It is noteworthy that ZnMb‐HSA shows long circulation lifetime in vivo.