title: Detergent induces the formation of IgG aggregates: a multi-methodological approach.
abstract: Role of micellar environment created by Triton X-100 (TX-100) and CHAPSO on protein conformation using IgG as a model system has been studied in this paper. A substantial amount of secondary structure with the reduction in constant tertiary contacts was obtained in both bovine and human IgG in the presence of 0.12 mM TX-100 where as 6 and 8 mM CHAPSO concentration was required for this type of secondary structure. Further addition of either of the detergents result in the induction of α-helix in both the IgGs as evident by helix specific peaks in the amide I region of FTIR and circular dichroism spectra. Tryptophan and 8-anilino-1-naphthalene-sulphonic acid (ANS) fluorescence confirmed changes in protein conformation upon addition of detergents. Maximum ANS binding at 0.12 mM TX-100 in both while 6 and 8 mM CHAPSO in bovine and human IgG respectively, indicate a compact ''molten-globule''-like conformation. An increase addition of these detergents results in the burial of hydrophobic patches of both IgG owing to aggregation. Presence of aggregates at 0.2 and 0.16 mM TX-100 and 8 and 9 mM CHAPSO, for bovine and human IgG respectively, was further confirmed by reduction in ANS fluorescence, dynamic light scattering study, thioflavin T fluorescence and congo red absorbance.
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Samreen
authors.initials: S
authors.lastname: Amani
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Faisal
authors.initials: F
authors.lastname: Nasim
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Taqi Ahmed
authors.initials: TA
authors.lastname: Khan
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Naveed Ahmad
authors.initials: NA
authors.lastname: Fazili
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Furkan
authors.affiliation: Department of Chemistry, Faculty of Science, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Imtiyaz Ahmad
authors.initials: IA
authors.lastname: Bhat
authors.affiliation: Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Javed Masood
authors.initials: JM
authors.lastname: Khan
authors.affiliation: Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Rizwan Hasan
authors.initials: RH
authors.lastname: Khan
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India. Electronic address: aabgeenanaim@gmail.com.
authors.forename: Aabgeena
authors.initials: A
authors.lastname: Naeem
mesh_terms: D000818:Animals; D002417:Cattle; D002793:Cholic Acids / Q000737:chemistry*; D002942:Circular Dichroism; D003902:Detergents / Q000737:chemistry*; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry*; D017830:Octoxynol / Q000737:chemistry*; D011487:Protein Conformation; D055550:Protein Stability
chemical_list: D002793:Cholic Acids; D003902:Detergents; D007074:Immunoglobulin G; C048531:chapso; D017830:Octoxynol
keywords: 8-anilino-1-naphthalene-sulphonic acid; ANS; Aggregation; BIgG; CD; CHAPSO; CR; DLS; Dynamic light scattering; HIgG; IgG; MG; Molten globule; TX-100; ThT; Thioflavin T; Triton X-100; bovine IgG; circular dichroism; congo red; dynamic light scattering; human IgG; immunoglobulin G; molten globule