Protein G Conjugated to R-PE

Protein G is an immunoglobulin-binding protein expressed in group C and G Streptococcal bacteria much like Protein A but with differing specificities. It is a 65-kDa (G148 protein G) and a 58 kDa (C40 protein G) cell surface protein that has found application in purifying antibodies through its binding to the Fc region. The native molecule also binds albumin, however, because serum albumin is a major contaminant of antibody sources, the albumin binding site has been removed from recombinant forms of Protein G. Phycoethyrin: Phycoethyrin (R-PE) is a 240 kDa protein from the light-harvesting phycobilliprotein, phycoerythrin is composed of a protein part, organised in a hexameric structure of alpha and beta chains, covalently binding chromophores called phycobilins. In the phycoerythrin family, the phycobilins are: phycoerythrobilin, the typical phycoerythrin acceptor chromophore, and sometimes phycourobilin (marine organisms). Phycoerythrins are the phycobilliprotein which bind the highest number of phycobilins (up to six per alpha-beta subunit dimer). R-PE purified from Poryhyra tenera; A565/A280 >5.0; A 1% 565 nm=82; Amax = 490, 545 and 566 nm; E max = 580 nm Protein G reacts strongly with IgG from mouse, human, bovine, goat, sheep, but poorly with guinea pig, porcine, dog and cat.