Primate (Macaca fascicularis) transferrin: isolation and partial characterization

The serum transferrin from the primate, Macaca fascicularis is isolated by a purification protocol consisting of ammonium sulphate precipitation and column chromatography. The hexose (galactose + mannose) content of Macaca transferrin is 4.7 mole per mole of protein. Quantitative determination of the sialic acid content shows that there are two sialic acid residues per molecule of Macaca transferrin. This conclusion is supported by the neuraminidase treatment of Macaca transferrin, in which there is a 2-step decrease in electrophoretic mobility. Monoferric Macaca transferrins with Fe3+ selectively labelled at the C- and N-terminal sites (TfFec and FeNTf) are prepared at pH 5.5 and 8.5 using ferric dinitrilotriacetate [Fe(NTA)2] chelate and ferrous ammonium sulphate, respectively.