Rosin Surfactant QRMAE Can Be Utilized as an Amorphous Aggregate Inducer: A Case Study of Mammalian Serum Albumin

Abstract

Quaternary amine of diethylaminoethyl rosin ester (QRMAE), chemically synthesized biocompatible rosin based cationic surfactant, has various biological applications including its use as a food product additive. In this study, we examined the amorphous aggregation behavior of mammalian serum albumins at pH 7.5, i.e., two units above their isoelectric points (pI ~5.5), and the roles played by positive charge and hydrophobicity of exogenously added rosin surfactant QRMAE. The study was carried out on five mammalian serum albumins, using various spectroscopic methods, dye binding assay, circular dichroism and electron microscopy. The thermodynamics of the binding of mammalian serum albumins to cationic rosin modified surfactant were established using isothermal titration calorimetry (ITC). It was observed that a suitable molar ratio of protein to QRMAE surfactant enthusiastically induces amorphous aggregate formation at a pH above two units of pI. Rosin surfactant QRMAE-albumins interactions revealed a unique interplay between the initial electrostatic and the subsequent hydrophobic interactions that play an important role towards the formation of hydrophobic interactions-driven amorphous aggregate. Amorphous aggregation of proteins is associated with varying diseases, from the formation of protein wine haze to the expansion of the eye lenses in cataract, during the expression and purification of recombinant proteins. This study can be used for the design of novel biomolecules or drugs with the ability to neutralize factor(s) responsible for the aggregate formation, in addition to various other industrial applications.

Biochemical and Biophysical Characterisation of the Hepatitis E Virus Guanine-7-Methyltransferase

“…To determine the binding affinity of MTase, we performed the titration of Mg 2+ against MTase at 25 °C. However, the k q value for the MTase–Mg 2+ system was ten times higher than the highest scatter collision quenching constant of innumerable quenchers with polymers (2 × 10 10 M −1 s −1 ) [ 27 ]. This reflects that quenching is not commenced by dynamic diffusion, but arises by creating powerful complex formation between MTase and Mg 2+ .…”

Aggregation and conformational stability evaluation of myoglobin in the presence of ionic surfactant

“…Light scattering was assessed and similar conclusions to ours were found. In another paper using human serum albumin, ThT binding assay was used to assess the influence of quaternary amine of rosin diethylaminoethyl ester (QRMAE) (Ishtikhar et al, 2015). The results concluded conformational destabilization with increasing concentration of QRMAE, similar to results presented in this paper.…”

Advances in Rosin-Based Chemicals: The Latest Recipes, Applications and Future Trends

“…Their potential applications include corrosion inhibitiors [104,191,192] dispersants for magnetite (Fe 3 O 4 ) nanoparticles [191,192] and inhibitors in protein aggregation processes [193,194,195]. In addition, a similar rosinyl triquaternary ammonium salt having antifungal activity was also reported [196].…”