One-third of protein formulations are multi-dose. These require antimicrobial preservatives (APs); however, some APs have been shown to cause protein aggregation. Our previous work on a model protein cytochrome c indicated that partial protein unfolding, rather than complete unfolding, triggers aggregation. Here, we examined the relative strength of five commonly used APs on such unfolding and ...

The folding of polypeptides into stable globular protein structures requires protein sequences with a relatively high hydrophobicity and secondary structure propensity. These biophysical properties, however, also favor protein aggregation via the formation of intermolecular beta-sheets and, as a result, globular structure and aggregation are inextricable properties of protein polypeptides. Aggr...

Effects of ?-cyclodextrin, ?CD, on refolding of lysozyme was investigated at pH 12 employing isothermal titration calorimetry (ITC) at 300K in 30mM Tris buffer solution. ?CD was employed as an anti-aggregation agent and the heats obtained for lysozyme+?CD interactions are reported and analyzed in terms of the extended solvation model. It was indicated that there are two sets of identical and no...

Protein aggregation is being found to be associated with an increasing number of human diseases. Aggregation can lead to a loss of function (lack of active protein) or to a toxic gain of function (cytotoxicity associated with protein aggregates). Although potentially harmful, protein sequences predisposed to aggregation seem to be ubiquitous in all kingdoms of life, which suggests an evolutiona...

Multidose protein formulations require an effective antimicrobial preservative (AP) to inhibit microbial growth during long-term storage of unused formulations. m-cresol (CR) is one such AP, but it has been shown to cause protein aggregation. However, the fundamental physical mechanisms underlying such AP-induced protein aggregation are not understood. In this study, we used a model protein cyt...

Aggregation or reversible self-association of protein therapeutics can arise through a number of different mechanisms. Five common aggregation mechanisms are described and their relations to manufacturing processes to suppress and remove aggregates are discussed.