Premium
Arginine–aromatic interactions and their effects on arginine‐induced solubilization of aromatic solutes and suppression of protein aggregation
Author(s) -
Shah Dhawal,
Li Jianguo,
Shaikh Abdul Rajjak,
Rajagopalan Raj
Publication year - 2011
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1002/btpr.710
Subject(s) - arginine , chemistry , lysozyme , peptide , aromatic amino acids , protein aggregation , solubilization , solubility , molecular dynamics , biophysics , biochemistry , amino acid , organic chemistry , computational chemistry , biology
We examine the interaction of aromatic residues of proteins with arginine, an additive commonly used to suppress protein aggregation, using experiments and molecular dynamics simulations. An aromatic‐rich peptide, FFYTP (a segment of insulin), and lysozyme and insulin are used as model systems. Mass spectrometry shows that arginine increases the solubility of FFYTP by binding to the peptide, with the simulations revealing the predominant association of arginine to be with the aromatic residues. The calculations further show a positive preferential interaction coefficient, Γ XP , contrary to conventional thinking that positive Γ XP 's indicate aggregation rather than suppression of aggregation. Simulations with lysozyme and insulin also show arginine's preference for aromatic residues, in addition to acidic residues. We use these observations and earlier results reported by us and others to discuss the possible implications of arginine's interactions with aromatic residues on the solubilization of aromatic moieties and proteins. Our results also highlight the fact that explanations based purely on Γ XP , which measures average affinity of an additive to a protein, could obscure or misinterpret the underlying molecular mechanisms behind additive‐induced suppression of protein aggregation. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012