Investigation of an albumin‐enriched fraction of human serum and its albuminome

Abstract

The removal of albumin and other high abundance proteins is a routine first step in the analysis of serum and plasma proteomes. However, as albumin can bind proteins and peptides, there is a universal concern as to how the serum proteome is changed by the removal of albumin. To address this concern, the current study was designed to identify proteins and peptides removed from the serum during albumin depletion; to determine which of these are bound to albumin (rather than copurified) and whether the bound proteins are intact proteins or peptide fragments. Sequential, independent analyses including both anti-albumin antibody (anti-HSA) affinity chromatography and SEC were used to isolate albumin-bound proteins. RP-HPLC and 1-D SDS-PAGE were then used to further separate the proteins prior to identification by MS/MS. Finally, whole protein molecular weight (MW) MS measurements coupled with protein coverage obtained by MS were combined to assess whether the bound proteins were intact or peptide fragments. Combining the results from multiple approaches, 35 proteins, of which 24 are intact, were found to be associated with albumin, and they include both known high and low abundance proteins.

GA/GB Fold switching may modulate fatty acid transfer from human serum albumin to bacteria

“…Remarkably, 35 proteins have been found to be associated to HSA under physiological conditions; the fraction of peptides and proteins bound to HSA has been defined as ''albuminome'' (1)(2)(3)(4)13). Interestingly, the GA module of the Finegoldia magna poly(A)-binding (PAB) protein has been reported to bind to HSA in the vicinity of the FA6 site (14, 15) (Fig.…”

Pseudo-enzymatic hydrolysis of 4-nitrophenyl acetate by human serum albumin: pH-dependence of rates of individual steps

“…Remarkably, 35 proteins have been found to be associated to HSA under physiological conditions; the fraction of peptides and proteins bound to HSA has been defined as ''albuminome'' [1][2][3][4][5][6].…”

Unraveling the Complexity of Circulating Forms of Brain Natriuretic Peptide

“…Recently, we published results from the investigation of albumin and its binding partners in serum. In this example, albumin was found to bind to intact proteins as well as peptides (3 ). In fact, of the 35 albumin-binding proteins we found in serum, 24 were intact.…”