The E104D mutation increases the susceptibility of human triosephosphate isomerase to proteolysis. Asymmetric cleavage of the two monomers of the homodimeric enzyme
Por:
De La Mora-De La Mora I., Torres-Larios A., Mendoza-Hernández G., Enriquez-Flores S., Castillo-Villanueva A., Mendez S.T., Garcia-Torres I., Torres-Arroyo A., Gómez-Manzo S., Marcial-Quino J., Oria-Hernández J., López-Velázquez G., Reyes-Vivas H.
Publicada:
1 dic 2013
Resumen:
The deficiency of human triosephosphate isomerase (HsTIM) generates neurological alterations, cardiomyopathy and premature death. The mutation E104D is the most frequent cause of the disease. Although the wild type and mutant exhibit similar kinetic parameters, it has been shown that the E104D substitution induces perturbation of an interfacial water network that, in turn, reduces the association constant between subunits promoting enzyme inactivation. To gain further insight into the effects of the mutation on the structure, stability and function of the enzyme, we measured the sensitivity of recombinant E104D mutant and wild type HsTIM to limited proteolysis. The mutation increases the susceptibility to proteolysis as consequence of the loss of rigidity of its overall 3-D structure. Unexpectedly, it was observed that proteolysis of wild type HsTIM generated two different stable nicked dimers. One was formed in relatively short times of incubation with proteinase K; as shown by spectrometric and crystallographic data, it corresponded to a dimer containing a nicked monomer and an intact monomer. The formation of the other nicked species requires relatively long incubation times with proteinase K and corresponds to a dimer with two clipped subunits. The first species retains 50% of the original activity, whereas the second species is inactive. Collectively, we found that the E104D mutant is highly susceptible to proteolysis, which in all likelihood contributes to the pathogenesis of enzymopathy. In addition, the proteolysis data on wild type HsTIM illustrate an asymmetric conduct of the two monomers. © 2013 Elsevier B.V.
Filiaciones:
De La Mora-De La Mora I.:
Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur 3700-C, Delegacion Coyoacan, D.F. CP 04530, Mexico
Torres-Larios A.:
Univ Nacl Autonoma Mexico, Inst Fisiol Celular, Mexico City 04510, DF, Mexico
Mendoza-Hernández G.:
Univ Nacl Autonoma Mexico, Fac Med, Dept Bioquim, Mexico City 04510, DF, Mexico
Enriquez-Flores S.:
Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur 3700-C, Delegacion Coyoacan, D.F. CP 04530, Mexico
Castillo-Villanueva A.:
Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur 3700-C, Delegacion Coyoacan, D.F. CP 04530, Mexico
Mendez S.T.:
Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur 3700-C, Delegacion Coyoacan, D.F. CP 04530, Mexico
Garcia-Torres I.:
Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur 3700-C, Delegacion Coyoacan, D.F. CP 04530, Mexico
Torres-Arroyo A.:
Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur 3700-C, Delegacion Coyoacan, D.F. CP 04530, Mexico
Gómez-Manzo S.:
Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur 3700-C, Delegacion Coyoacan, D.F. CP 04530, Mexico
Marcial-Quino J.:
Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur 3700-C, Delegacion Coyoacan, D.F. CP 04530, Mexico
Oria-Hernández J.:
Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur 3700-C, Delegacion Coyoacan, D.F. CP 04530, Mexico
López-Velázquez G.:
Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur 3700-C, Delegacion Coyoacan, D.F. CP 04530, Mexico
Reyes-Vivas H.:
Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur 3700-C, Delegacion Coyoacan, D.F. CP 04530, Mexico
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