Liquid chromatography and electrospray mass spectrometric mapping of peptides from human plasma filtrate

We present a multidimensional approach to map the composition of complex pe ptide mixtures obtained as crude extract from biological liquids by (1) cat ion exchange chromatography and (2) subsequent microbore reversed-phase liq uid chromatography and electrospray mass spectrometry coupling (LC-MS). Hum an hemofiltrate is an equivalent to blood and is used to obtain peptide mat erial in large quantities from patients with chronic renal failure. The upp er exclusion limit of the filtration membranes used results in a protein-fr ee filtrate containing peptides in a range up to 20 ku. Using this unique p eptide source, several thousand peptides were detected and an LC-MS data ba se of circulating human peptides was created. The search for known peptides by their molecular mass is a reliable method to guide peptide purification . (J Am Soc Mass Spectrom 1999, 10, 45-54) (C) 1999 American Society for Ma ss Spectrometry.