Bioanalysis (Epub ahead of print) ISSN 1757-6180
Review
part of
10.4155/bio-2016-0269 © 2017 Future Science Ltd
Protein aggregation is a common biological phenomenon which is responsible for
degenerative diseases and is problematic in the pharmaceutical industry. According to
the rules provided by regulatory agencies, industry is supposed to assess the product
quality regarding the presence of subvisible particles. Also, they should evaluate
the technologies that are used to measure these particles. Therefore, US FDA and
industry have been looking for methods capable of accurately characterizing the
protein products. Four sizing techniques reviewed here are good candidates to be
used for characterization of protein and their aggregates: dynamic light scattering,
size-exclusion chromatography, electron microscopy and Taylor dispersion analysis.
The first three are more established techniques while the last one is a more recent
and growing technique.
First draft submitted: 13 October 2016; Accepted for publication: 25 November 2016;
Published online: 18 January 2017
Keywords: dynamiclightscattering•electronmicroscopy•pharmaceuticals•protein
aggregation•protein-basedtherapeutics•size-exclusionchromatography•sizingtechniques
•Taylordispersionanalysis
Proteins play essential roles in all life forms,
including the human body. They can be
major components of cell structure, cata-
lyze biochemical reactions, act as receptors
for signaling molecules and transport mol-
ecules within a cell [1] . They naturally require
a 3D-folded structure to function effec-
tively [2,3] . The fundamental forces that drive
protein folding include van der Waals and
hydrophobic interactions, hydrogen bonding,
as well as charge–charge interaction, among
others [4] . These types of interactions occur
between amino acids, the building blocks
of proteins, and are critical to maintaining
structural integrity. However, these interac-
tions not only occur between amino acids
of the same protein, but also occur between
amino acids of adjacent proteins. Interpro-
tein interactions can result in aggregation if
the newly synthesized protein does not fold
correctly, or if certain chaperone molecules
within the cell fail to initiate the degrada-
tion or refolding of the faulty protein. Con-
sequently, protein aggregation is an inevi-
table phenomenon that occurs under certain
conditions [2] ; mutations, defects in protein
biogenesis, environmental stress conditions
and aging can all cause protein aggregation
in cells [5] . This aggregation has been iden-
tified as the primary cause of neurodegen-
erative diseases such as Alzheimer’s disease
(AD), Parkinson’s disease and Huntington’s
disease [6] . Protein aggregation is not only
the cause of the diseases as mentioned earlier
but also a major concern for pharmaceutical
industries.
Pharmaceutical companies are becoming
increasingly interested in proteins for the
development of therapeutic drugs. There has
been a remarkable increase in the develop-
ment of protein-based therapeutics since the
approval of insulin as the first recombinant
Particle sizing methods for the detection of
protein aggregates in biopharmaceuticals
Akram Khodabandehloo
1
& David Da Yong Chen*
,1
1
DepartmentofChemistry,University
ofBritishColumbia,Vancouver,BC,
V6T1Z1,Canada
*Authorforcorrespondence:
Tel.:+16048220878
chen@chem.ubc.ca
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