title: Quantification of protein-bound sodium dodecyl sulfate by Rhodamine B: a method for identification of kinetically stable proteins.
abstract: Sodium dodecyl sulfate (SDS) bound to proteins in solution could be estimated by passing through Extracti-Gel that removes free SDS followed by specific interaction of the fluorophore Rhodamine B with protein-bound SDS. The resulting fluorescence intensity is compared with a calibration curve. Whereas globular proteins respond to binding of 1.4 mg SDS/mg protein under native conditions, "kinetically stable" proteins that are otherwise resistant to denaturation due to structural integrity show a low level of SDS binding. Analysis of the circular dichroism spectrum shows that in spite of the low level of SDS binding to kinetically stable proteins under nondenaturing conditions, the detergent generates considerable secondary structure in these proteins. Because the low level of SDS binding is a general feature of kinetically stable proteins, the protocol may fulfill one of the criteria to classify a protein as kinetically stable.
authors.affiliation: Division of Structural Biology and Bioinformatics, Indian Institute of Chemical Biology, Jadavpur, Kolkata 700 032, India.
authors.forename: Reema
authors.initials: R
authors.lastname: Bhattacharya
authors.forename: Debratna
authors.initials: D
authors.lastname: Mukherjee
authors.forename: Debasish
authors.initials: D
authors.lastname: Bhattacharyya
mesh_terms: D000818:Animals; D001671:Biochemistry / Q000379:methods*; D002374:Catalase / Q000032:analysis; D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008024:Ligands; D055550:Protein Stability; D017433:Protein Structure, Secondary; D011506:Proteins / Q000032:analysis*; D012015:Reference Standards; D012235:Rhodamines / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000032:analysis; D012967:Sodium Dodecyl Sulfate / Q000032:analysis*; D013050:Spectrometry, Fluorescence
chemical_list: D008024:Ligands; D011506:Proteins; D012235:Rhodamines; D012710:Serum Albumin, Bovine; D012967:Sodium Dodecyl Sulfate; D002374:Catalase; C029773:rhodamine B