Medicinal chemistry meets proteomics: fractionation of the human plasma proteome

Human plasma and its fractions/derivatives are frequently used materials in biomedicine as it contains thousands and thousands of proteins representing the majority of human proteome. Several important methods were developed in the past for the fractionation of this important biological fluid and its use for medicinal purposes. One of the greatest challenges is the very large dynamic range of plasma proteins ranging up to 10-12 orders of magnitude. Early attempts were mainly based on methods such as salting out or cold ethanol precipitation, as well as chromatography utilizing affinity, size exclusion, ion exchange and hydrophobic interaction techniques. More recently, fractionation applications started with the depletion of the high abundant plasma components, such as serum albumin and immunoglobulins, before isolating lower abundant proteins of interest. Plasma volumes were utilized from the milliliter scale for diagnostic applications to hundreds of liters for industrial scale plasma fractionation (e.g., medicinal product manufacturing). In this paper we review this important part of medicinal chemistry, highlighting the traditional methods along with some of their variations as well as the most significant recent achievements of the field.