title: Chemical and thermal unfolding of calreticulin.
abstract: Calreticulin is a soluble endoplasmic reticulum chaperone, which has a relatively low melting point due to its remarkable structure with a relatively high content of flexible structural elements. Using far ultraviolet circular dichroism (CD) spectroscopy and a fluorescent dye binding thermal shift assay, we have investigated the chemical and thermal stability of calreticulin. When the chemical stability of calreticulin was assessed, a midpoint for calreticulin unfolding was calculated to 3.0M urea using CD data at 222 nm. Using the fluorescent dye binding thermal shift assay, calreticulin was found to obtain a molten structure in urea concentrations between 1-1.5 M urea, and to unfold/aggregate at high and low pH values. The results demonstrated that the fluorescent dye binding assay could measure the thermal stability of calreticulin in aqueous buffers with results comparable to melting points obtained by other techniques.
authors.affiliation: Department of Clinical Biochemistry and Immunology, Statens Serum Institut, Artillerivej 5, DK-2300, Copenhagen, Denmark.
authors.forename: K
authors.initials: K
authors.lastname: Duus
authors.forename: N
authors.initials: N
authors.lastname: Larsen
authors.forename: T A T
authors.initials: TA
authors.lastname: Tran
authors.forename: E
authors.initials: E
authors.lastname: Güven
authors.forename: L K
authors.initials: LK
authors.lastname: Skov
authors.forename: C
authors.initials: C
authors.lastname: Jespersgaard
authors.forename: M
authors.initials: M
authors.lastname: Gajhede
authors.forename: G
authors.initials: G
authors.lastname: Houen
mesh_terms: D037282:Calreticulin / Q000737:chemistry* / Q000378:metabolism*; D002942:Circular Dichroism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011489:Protein Denaturation; D017510:Protein Folding; D055550:Protein Stability; D058767:Protein Unfolding; D013696:Temperature; D014508:Urea / Q000737:chemistry
chemical_list: D037282:Calreticulin; D014508:Urea