title: Influence of stabilizers cosolutes on catalase conformation.
abstract: The effects of sucrose, mannitol and betaine on the thermodynamic stability and the conformational state of the catalase enzyme were analyzed in order to understand the molecular mechanism whereby the solutes stabilized the enzyme. Catalase was selected as the model enzyme because it is used in several biotechnological processes. In the presence of each cosolute, our data have shown that there was a significant increase in the thermal stability of catalase. A minor stabilization in the enzyme secondary structure were induced by these cosolutes, as circular dichroism in the far UV region has demonstrated. Furthermore, our results support the idea that the overall native structure of catalase becomes more rigid, at least in certain surface areas, in the presence of the assayed stabilizers. This last finding can be reasonably explained by the exclusion mechanism of cosolutes from the protein surface which increases the structured water around this area.
authors.affiliation: Lab. of Physical Chemistry Applied to the Bioseparation, Faculty of Biochemical and Pharmaceutical Sciences, CONICET, National University of Rosario, (S2002RLK) Rosario, Argentina. sbelluzo@fbioyf.unr.edu.ar
authors.forename: Soledad
authors.initials: S
authors.lastname: Belluzo
authors.forename: Valeria
authors.initials: V
authors.lastname: Boeris
authors.forename: Beatriz
authors.initials: B
authors.lastname: Farruggia
authors.forename: Guillermo
authors.initials: G
authors.lastname: Picó
mesh_terms: D000818:Animals; D001622:Betaine / Q000494:pharmacology; D002374:Catalase / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D002942:Circular Dichroism; D004795:Enzyme Stability / Q000187:drug effects; D008099:Liver / Q000737:chemistry / Q000201:enzymology*; D008353:Mannitol / Q000494:pharmacology; D011489:Protein Denaturation / Q000187:drug effects; D017510:Protein Folding / Q000187:drug effects*; D017433:Protein Structure, Secondary; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013395:Sucrose / Q000494:pharmacology; D013816:Thermodynamics; D014867:Water
chemical_list: D012996:Solutions; D014867:Water; D008353:Mannitol; D001622:Betaine; D013395:Sucrose; D002374:Catalase