Biophysical Effect of Amino Acids on the Prevention of Protein Aggregation

Abstract

Each protein folds into a unique and native structure spontaneously. However, during the unfolding or refolding process, a protein often tends to form aggregates. To establish a method to prevent undesirable protein aggregation and to increase the stability of native protein structures under deterioration conditions, two types of aggregation conditions, thermal unfolding-induced aggregation and dilution-induced aggregation from denatured state, were studied in the presence of additional amino acids and ions using lysozyme as a model protein. Among 15 amino acids tested, arginine exhibited the best results in preventing the formation of aggregates in both cases. Further biophysical studies revealed that arginine did not change the thermal denaturation temperature (T(m)) of the lysozyme. The preventive effect of arginine on aggregation was not dependent on the size or isoelectric point of eight kinds of proteins tested.

Promotion and Suppression of Thermal Aggregation of β-Lactoglobulin by Arginine: A Concentration Dependent Mechanism

“…Interestingly L-arginine and its derivatives were widely used in the industrial production process for plasminogen activator and continued to be marketed as bio-pharmaceuticals to this days also. Arginine exhibited the best results in preventing the formation of aggregates of lysozyme as a model protein under thermal stress and refolding pathway from previously denatured state in comparison to other 14 amino acids [1]. The preventive actions of Arg have been also reported by Shiraki and coworkers with other eight kinds of proteins.…”

“…Solubility of heat treated β-lg solutions was measured according to standard procedures, with a little modification [1]. Protein solutions of different concentrations (1 mg mL -1 , 2 mg mL -1 ) containing arginine (0 -1.0M) in phosphate buffer (pH 6.5) were incubated at 80…”

“…L-Arginine (Arg) is one of the most commonly used suppressors of aggregation of protein and hormones in vitro [1][2][3]. Its general acceptability as a suppressor of protein aggregates is well known, but the mechanism of its action in molecular detail remains elusive in spite of having a series of progress with Arg and its derivatives also [4].…”

“…The preventive actions of Arg have been also reported by Shiraki and coworkers with other eight kinds of proteins. It was stated that the suppression effect was independent of size and/or iso-electric point of the proteins [1]. Nonetheless, one novel derivative, arginine ethyl ester significantly prevents thermal inactivation and aggregation of lysozyme whereas only Arg and guanidine (Gdn.HCl) was less effective in case of heat labile proteins [6].…”

Synthesis and Crystal Structure of 2-[(4-Chlorobenzoyl)amino]-3-(4-formylphenyl)prop-2-enoic Acid

“…Crystal structure of some useful substituted prop-2-enoic acid exist in the literature, viz., (Z)-3-(Benzylcarbamoyl)prop-2-enoic acid 1 , (E)-3-(4-Chlorophenyl)-2-phenylprop-2-enoic acid 2 , 3-Methoxy-2-[2-({[6-(trifluoromethyl)-pyridin-2-yl]oxy}methyl)phenyl]prop-2-enoic acid 3 , (2Z)-4-[(2-Hydroxyphenyl)carbamoyl]-prop-2-enoic acid 4 . Recently, amino acids and their derivatives, such as glycine ethyl ester which are non-denaturating reagents, have been RESEARCH ARTICLE widely used in biochemical studies to increase refolding yields by decreasing aggregation and to increase protein stability [5][6][7][8][9][10] . We report herein the synthesis and crystal structure of 2-[(4-chlorobenzoyl)amino]-3-(4-formylphenyl)prop-2-enoic acid.…”