title: Denaturing action of urea and guanidine hydrochloride towards two thermophilic esterases.
abstract: The stability of two thermophilic esterases, AFEST from Archaeoglobus fulgidus and EST2 from Alicyclobacillus acidocaldarius, against the denaturing action of urea and guanidine hydrochloride has been investigated by means of steady-state fluorescence and circular dichroism measurements. Experimental results indicate that the two enzymes, even though very resistant to temperature and urea, show a resistance to guanidine hydrochloride weaker than expected on the basis of data collected so far for a large set of globular proteins. Structural information available for AFEST and EST2 and ideas that emerged from studies on the molecular origin of the greater thermal stability of thermophiles allow the suggestion of a reliable rationale. The present results may be an indication that the optimization of charge-charge interactions on the protein surface is a key factor for the stability of the two esterases.
authors.affiliation: Department of Chemistry, University of Naples Federico II, Via Cintia, 45-80126 Naples, Italy. delvecchio@chemistry.unina.it
authors.forename: Pompea
authors.initials: P
authors.lastname: Del Vecchio
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Graziano
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Granata
authors.forename: Guido
authors.initials: G
authors.lastname: Barone
authors.forename: Luigi
authors.initials: L
authors.lastname: Mandrich
authors.forename: Mosè
authors.initials: M
authors.lastname: Rossi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Manco
mesh_terms: D019609:Archaeoglobus / Q000201:enzymology; D001407:Bacillus / Q000201:enzymology; D002942:Circular Dichroism; D004950:Esterases / Q000737:chemistry*; D019791:Guanidine / Q000737:chemistry*; D011489:Protein Denaturation; D013050:Spectrometry, Fluorescence; D014508:Urea / Q000737:chemistry*
chemical_list: D014508:Urea; D004950:Esterases; D019791:Guanidine