title: 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.
authors.affiliation: Protein Biophysics Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh - 202002, India.
authors.forename: Mohd
authors.initials: M
authors.lastname: Ishtikhar
authors.affiliation: Protein Biophysics Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh - 202002, India.
authors.forename: Tajjali Ilm
authors.initials: TI
authors.lastname: Chandel
authors.affiliation: Karmanos Cancer Institute, Wayne State University, School of Medicine, 707 HWCRC 4100 John R. St., Detroit, MI 48201, United States of America.
authors.forename: Aamir
authors.initials: A
authors.lastname: Ahmad
authors.affiliation: Surfactant Research Chair, Department of Chemistry, College of Science, King Saud University PO Box-2455, Riyadh-11541, Saudi Arabia.
authors.forename: Mohd Sajid
authors.initials: MS
authors.lastname: Ali
authors.affiliation: Surfactant Research Chair, Department of Chemistry, College of Science, King Saud University PO Box-2455, Riyadh-11541, Saudi Arabia.
authors.forename: Hamad A
authors.initials: HA
authors.lastname: Al-Lohadan
authors.affiliation: Surfactant Research Chair, Department of Chemistry, College of Science, King Saud University PO Box-2455, Riyadh-11541, Saudi Arabia.
authors.forename: Ayman M
authors.initials: AM
authors.lastname: Atta
authors.affiliation: Protein Biophysics Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh - 202002, India.
authors.forename: Rizwan Hasan
authors.initials: RH
authors.lastname: Khan
mesh_terms: D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007526:Isoelectric Point; D066329:Protein Aggregates / Q000187:drug effects*; D011817:Rabbits; D012116:Resins, Plant / Q000737:chemistry / Q000494:pharmacology*; D012709:Serum Albumin / Q000737:chemistry* / Q000378:metabolism*; D012756:Sheep; D013501:Surface-Active Agents / Q000737:chemistry / Q000494:pharmacology*; D013552:Swine; D013816:Thermodynamics
chemical_list: D066329:Protein Aggregates; D012116:Resins, Plant; D012709:Serum Albumin; D013501:Surface-Active Agents; C013893:rosin