Albumin-heme oxygen carriers

Abstract

Human serum albumin (HSA) is the most prominent plasma protein in the circulatory system and has a remarkable capability to bind a broad range of hydrophobic molecules. Protoheme IX released from hemoglobin (Hb) is also captured by HSA with a high binding constant. This strong affinity of HSA for heme has stimulated efforts to develop albumin as an artificial hemoprotein which is capable of mimicking the O2 transport of Hb. In this chapter, we report on our representative results of albumin-heme O2 carriers; HSA incorporating synthetic heme, its poly(ethylene glycol) conjugate, and recombinant HSA mutant complexing protoheme IX. These protein hybrids might be of great medical importance not only for RBC alternatives, but also for O2-providing therapeutic reagents.