Classification of protein aggregates

Comparison of protein aggregates/self-associated species between laboratories and across disciplines is complicated by the imprecise language presently used to describe them. In this commentary, we propose a standardized nomenclature and classification scheme that can be applied to describe all protein aggregates. Five categories are described under which a given aggregate may be independently classified: size, reversibility/dissociation, conformation, cova- lent modification, and morphology. Possible subclassifications within each category, several ex- amples of applications of the nomenclature, and difficulties in making appropriate assignments will be discussed. © 2011 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 101:493-498, 2012