tailieunhanh - Báo cáo khoa học: Effects of the G376E and G157D mutations on the stability of yeast enolase – a model for human muscle enolase deficiency

The first known human enolase deficiency was reported in 2001 [Comi GP, Fortunato F, Lucchiari S, Bordoni A, Prelle A, Jann S, Keller A, Ciscato P, Galbiati S, Chiveri Let al.(2001) Ann Neurol50,202–207]. The subject had inherited two mutated genes forb-enolase. These mutations changed glycine 156 to aspartate and glycine 374 to glutamate. | ỊFEBS Journal Effects of the G376E and G157D mutations on the stability of yeast enolase - a model for human muscle enolase deficiency Songping Zhao Bonny S. F. Choy and Mary J. Kornblatt Department of Chemistry and Biochemistry Concordia University Montreal Canada Keywords muscle enolase mutations proteolysis stability subunit interactions Correspondence M. J. Kornblatt Department of Chemistry and Biochemistry Concordia University 7141 Sherbrooke Street W. Montreal QC Canada H3G 1A7 Fax 1 514 848 2868 Tel 1 514 848 2424 ext 3384 E-mail judithk@ These authors contributed equally to this work Received 12 September 2007 revised 1 November 2007 accepted 5 November 2007 The first known human enolase deficiency was reported in 2001 Comi GP Fortunato F Lucchiari S Bordoni A Prelle A Jann S Keller A Ciscato P Galbiati S Chiveri L et al. 2001 Ann Neurol 50 202-207 . The subject had inherited two mutated genes for b-enolase. These mutations changed glycine 156 to aspartate and glycine 374 to glutamate. In order to study the effects of these changes on the structure and stability of enolase we have introduced the corresponding changes G157D and G376E into yeast enolase. The two variants are correctly folded. They are less stable than wild-type enolase with respect to thermal denaturation and both have increased Kd values for subunit dissociation. At 37 C in the presence of salt both are partially dissociated and are extensively cleaved by trypsin. Under the same conditions wild-type enolase is fully dimeric and is only slightly cleaved by trypsin. However wild-type enolase is also extensively cleaved if it is partially dissociated. The identification of the cleavage sites and spectral studies of enolase have revealed some of the structural differences between the dimeric and monomeric forms of this enzyme. doi Enolase EC an essential enzyme of glycolysis and gluconeogenesis catalyses the interconversion of .