title: Differences in the pathways of proteins unfolding induced by urea and guanidine hydrochloride: molten globule state and aggregates.
abstract: It was shown that at low concentrations guanidine hydrochloride (GdnHCl) can cause aggregation of proteins in partially folded state and that fluorescent dye 1-anilinonaphthalene-8-sulfonic acid (ANS) binds with these aggregates rather than with hydrophobic clusters on the surface of protein in molten globule state. That is why the increase in ANS fluorescence intensity is often recorded in the pathway of protein denaturation by GdnHCl, but not by urea. So what was previously believed to be the molten globule state in the pathway of protein denaturation by GdnHCl, in reality, for some proteins represents the aggregates of partially folded molecules.
authors.affiliation: Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology of the Russian Academy of Science, St. Petersburg, Russia.
authors.forename: Olga I
authors.initials: OI
authors.lastname: Povarova
authors.forename: Irina M
authors.initials: IM
authors.lastname: Kuznetsova
authors.forename: Konstantin K
authors.initials: KK
authors.lastname: Turoverov
mesh_terms: D000199:Actins / Q000737:chemistry; D000817:Anilino Naphthalenesulfonates / Q000737:chemistry; D000818:Animals; D024402:Carbonic Anhydrase II / Q000737:chemistry; D002417:Cattle; D005456:Fluorescent Dyes / Q000737:chemistry; D019791:Guanidine / Q000494:pharmacology*; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D018482:Muscle, Skeletal / Q000737:chemistry; D011487:Protein Conformation / Q000187:drug effects; D011489:Protein Denaturation / Q000187:drug effects; D058767:Protein Unfolding / Q000187:drug effects*; D011506:Proteins / Q000737:chemistry*; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D014508:Urea / Q000494:pharmacology*
chemical_list: D000199:Actins; D000817:Anilino Naphthalenesulfonates; D005456:Fluorescent Dyes; D011506:Proteins; C027132:1-anilino-8-naphthalenesulfonate; D014508:Urea; D024402:Carbonic Anhydrase II; D019791:Guanidine