The stability of acetyl-esterase, Aes, from Escherichia coli against the denaturing action of urea and guanidine hydrochloride, GuHCl, has been investigated by means of circular dichroism and fluorescence measurements. The urea-induced unfolding curves show a single inflection point at 6.2 M urea, whereas the GuHCl-induced curves show two inflection points at 1.4 and 3.1 M GuHCl. The unfolding process is reversible with both urea and GuHCl. These results, together with similar experimental data on the mutant form V20D-Aes, suggest the presence of two domains in the Aes structure, which unfold more or less independently depending on the denaturant used. This is also supported by a 3D model obtained by homology modeling using the structure of brefeldine as a template. The effect of NaCl on the urea-induced unfolding curves of the enzyme has also been investigated.
Denaturant-induced unfolding of acetyl-esterase from Escherichia coli / DEL VECCHIO, POMPEA GIUSEPPINA GRAZIA; G., Graziano; V., Granata; T., Farias; Barone, Guido; L., Mandrich; Rossi, Mose'; G., Manco. - In: BIOCHEMISTRY. - ISSN 0006-2960. - 43:46(2004), pp. 14637-14643. [10.1021/bi048344f]
Denaturant-induced unfolding of acetyl-esterase from Escherichia coli
DEL VECCHIO, POMPEA GIUSEPPINA GRAZIA;BARONE, GUIDO;ROSSI, MOSE';
2004
Abstract
The stability of acetyl-esterase, Aes, from Escherichia coli against the denaturing action of urea and guanidine hydrochloride, GuHCl, has been investigated by means of circular dichroism and fluorescence measurements. The urea-induced unfolding curves show a single inflection point at 6.2 M urea, whereas the GuHCl-induced curves show two inflection points at 1.4 and 3.1 M GuHCl. The unfolding process is reversible with both urea and GuHCl. These results, together with similar experimental data on the mutant form V20D-Aes, suggest the presence of two domains in the Aes structure, which unfold more or less independently depending on the denaturant used. This is also supported by a 3D model obtained by homology modeling using the structure of brefeldine as a template. The effect of NaCl on the urea-induced unfolding curves of the enzyme has also been investigated.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
