Other blood proteins act as enzymes, complement components, protease inhibitors or kinin precursors.
Serum albumin accounts for 55% of blood proteins,[1] is a major contributor to maintaining the oncotic pressure of plasma and assists, as a carrier, in the transport of lipids and steroid hormones.
Globulins make up 38% of blood proteins and transport ions, hormones, and lipids assisting in immune function.
Current research regarding blood plasma proteins is centered on performing proteomics analyses of serum/plasma in the search for biomarkers.
[citation needed] Scientists are able to identify blood proteins using Photo-affinity labeling, a means of using photo-reactive ligands as a labeling agent to identify targeted proteins.