Development of sensitive metalloporphyrin probes for chemiluminescent imaging detection of serum proteins.

The development of metalloporphyrin- (ferric protoporphyrin IX chloride (FePP), cobalt (III) protoporphyrin IX chloride, copper (II) protoporphyrin IX) enhanced chemiluminescent (CL) imaging detection of serum proteins after PAGE is described in this article. The detection is based on the catalytic activity of metalloporphyrins, especially FePP, in the CL reaction of the luminol-H2O2 system. Some relatively low abundant proteins such as hemopexin (Hpx) and complement C4 are sensitively detected by FePP-enhanced CL imaging. Other proteins such as haptoglobin, apolipoprotein A-1, complement C3, and alpha-1-antitrypsin are also detected and identified by MS and MS/MS techniques. Detection limit of Hpx is as low as 20 ng, without the need of expensive antibodies or tedious immunoassay procedures. The mechanism of the proposed method is discussed employing standard proteins. The application to the analysis of different protein patterns in healthy people and in Thalassemia patients is being investigated.