Serum albumin is the most abundant protein in plasma, has many
physiological functions, and is in contact with most of the cells and
tissues of the human body. Post-translational modifications (PTMs) may
affect functions, stability, and localization of albumin. Here we report
the identification of 61 novel PTMs of human serum albumin (HSA).
Phosphorylation, glycosylation, nitrosylation, deamidation, methylation,
acetylation, palmitoylation, geranylation, and farnesylation are
examples of the identified 31 types of PTMs. Mass spectrometry was used
for the identification of PTMs in a purified HSA and HSA from human
plasma. Three-dimensional modeling of albumin with selected PTMs showed
the location of these PTMs in the regions involved in interactions of
the albumin with drugs, metals, and fatty acids. The location of PTMs in
these regions may modify the binding capacity of albumin. This report
adds 61 novel PTMs to the catalog of human albumin.