Differential effects on enzyme stability and kinetic parameters of mutants related to human triosephosphate isomerase deficiency
Por:
Cabrera, Nallely, Torres-Larios, Alfredo, Garcia-Torres, Itzhel, Enriquez-Flores, Sergio, Perez-Montfort, Ruy
Publicada:
1 jun 2018
Resumen:
Human triosephosphate isomerase (TIM) deficiency is a very rare disease,
but there are several mutations reported to be causing the illness. In
this work, we produced nine recombinant human triosephosphate isomerases
which have the mutations reported to produce TIM deficiency. These
enzymes were characterized biophysically and biochemically to determine
their kinetic and stability parameters, and also to substitute TIM
activity in supporting the growth of an Escherichia coli strain lacking
the tim gene. Our results allowed us to rate the deleteriousness of the
human TIM mutants based on the type and severity of the alterations
observed, to classify four ``unknown severity mutants'' with altered
residues in positions 62, 72, 122 and 154 and to explain in structural
terms the mutation V231M, the most affected mutant from the kinetic
point of view and the only homozygous mutation reported besides E104D.
Filiaciones:
Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Av. Universidad 3000, Coyoacán, Ciudad de México, Mexico
Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Coyoacán, Ciudad de México, Mexico
Univ Nacl Autonoma Mexico, Inst Fisiol Celular, Dept Bioquim & Biol Estruct, Av Univ 3000, Mexico City 04510, DF, Mexico
Inst Nacl Pediat, Lab Bioquim Genet, Insurgentes Sur 3700-C, Mexico City 04530, DF, Mexico
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