Protein Aggregation‐Suppression: Molecular Clusters of Arginine are responsible

Abstract

Aggregation of unfolded proteins occurs through the exposed hydrophobic surfaces. Any mechanism of aggregation‐supression should explain these hydrophobic interactions. The mechanism of action of arginine as aggregation‐suppressor is not understood. We propose a mechanism based on the hydrophobic interactions of arginine.Arginine solutions display hydrotropic effect on pyrene. ANS fluorescence studies indicate the presence of hydrophobic environment. Mass spectroscopic analyses and light scattering studies indicate that arginine exists as clusters in the gas phase and in solution. Arginine changes the RPC elution profile and the hydrodynamic volume of Alzheimer's amyloid beta 1–42 (Aβ1–42). Arginine increases the solubility of Aβ1–42 peptide and decreases the aggregation.Our results show that molecular clusters of arginine in solutions display a hydrophobic surface by the alignment of its three methylene groups. The hydrophobic surfaces of the proteins and the arginine clusters interact. The masking of hydrophobic surface inhibits protein‐protein aggregation. This study was supported by the Department of Biotechnology, Government of India.