title: Conformational changes at the active site of pantetheine hydrolase during denaturation by guanidine hydrochloride.
abstract: Conformational changes at the active site of pantetheine hydrolase (EC3.5.1.-) during guanidine hydrochloride (GndHCl) denaturation were investigated by UV and circular dichroism spectroscopy and by electron spin resonance spectroscopy, following the spectral behaviour of the nitroxide radicals (N-(1-oxyl-2,2,5,5,-tetramethyl-3-pyrrolidinyl) iodacetamide) covalently linked to the two active site cysteine residues. At low denaturant concentrations (0.2 M) no conformational changes may be observed, whereas the catalytic activity, is strongly affected. The results indicate that the active site of pantetheine hydrolase is labile and unfolds under conditions in which no global tertiary structure modifications can be observed.
authors.affiliation: Dipartimento di Biologia di Base e Applicata, University of L'Aquila, Italy. giusi.pitari@aquila.infn.it
authors.forename: G
authors.initials: G
authors.lastname: Pitari
authors.forename: A A
authors.initials: AA
authors.lastname: D'Archivio
authors.forename: L
authors.initials: L
authors.lastname: Di Leandro
authors.forename: G
authors.initials: G
authors.lastname: Antonini
authors.forename: A
authors.initials: A
authors.lastname: Panatta
authors.forename: E
authors.initials: E
authors.lastname: Tettamanti
authors.forename: S
authors.initials: S
authors.lastname: Duprè
authors.forename: F
authors.initials: F
authors.lastname: Malatesta
mesh_terms: D000581:Amidohydrolases / Q000737:chemistry*; D001665:Binding Sites; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D058851:GPI-Linked Proteins; D019791:Guanidine / Q000737:chemistry*; D011487:Protein Conformation; D011489:Protein Denaturation; D013113:Spin Labels
chemical_list: D003497:Cyclic N-Oxides; D058851:GPI-Linked Proteins; D013113:Spin Labels; C003028:N-(1-oxyl-2,2,6,6-tetramethyl-4-piperidinyl)iodoacetamide; D000581:Amidohydrolases; C022314:pantetheinase; D019791:Guanidine