Aggregation Suppression of Proteins by Arginine During Thermal Unfolding

Title: Aggregation Suppression of Proteins by Arginine During Thermal Unfolding

Volume: 13 Issue: 9

Author(s): Tsutomu Arakawa, Yoshiko Kita, Daisuke Ejima, Kouhei Tsumoto and Harumi Fukada

Affiliation:

Keywords: Arginine, aggregation suppression, interleulin-6, monoclonal antibody, protein stabilization

Abstract: Arginine has been used to suppress aggregation of proteins during refolding and purification. We have further studied in this paper the aggregation-suppressive effects of arginine on two commercially important proteins, i.e., interleukine- 6 (IL-6) and a monoclonal antibody (mAb). These proteins show extensive aggregation in aqueous buffers when subjected to thermal unfolding. Arginine suppresses aggregation concentration-dependently during thermal unfolding. However, this effect was not specific to arginine, as guanidine hydrochloride (GdnHCl) at identical concentrations also was effective. While equally effective in aggregation suppression during thermal unfolding, arginine and GdnHCl differed in their effects on the structure of the native proteins. Arginine showed no apparent adverse effects on the native protein, while GdnHCl induced conformational changes at room temperature, i.e., below the melting temperature. These additives affected the melting temperature of IL-6 as well; arginine increased it concentration-dependently, while GdnHCl increased it at low concentration but decreased at higher concentration. These results clearly demonstrate that arginine suppresses aggregation via different mechanism from that conferred by GdnHCl.

Cite this article as:

Arakawa Tsutomu, Kita Yoshiko, Ejima Daisuke, Tsumoto Kouhei and Fukada Harumi, Aggregation Suppression of Proteins by Arginine During Thermal Unfolding, Protein & Peptide Letters 2006; 13 (9) . https://dx.doi.org/10.2174/092986606778256171