The Importance of Polarity in the Evolution of the K Binding Site of Pyruvate KinaseReportar como inadecuado




The Importance of Polarity in the Evolution of the K Binding Site of Pyruvate Kinase - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

1

Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 Distrito Federal, Mexico

2

Departamento de Bioquímica, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 Distrito Federal, Mexico





*

Author to whom correspondence should be addressed.



Abstract In a previous phylogenetic study of the family of pyruvate kinase, we found one cluster with Glu117 and another with Lys117. Those sequences with Glu117 have Thr113 and are K+-dependent, whereas those with Lys117 have Leu113 and are K+-independent. The carbonyl oxygen of Thr113 is one of the residues that coordinate K+ in the active site. Even though the side chain of Thr113 does not participate in binding K+, the strict co-evolution between position 117 and 113 suggests that T113 may be the result of the evolutionary pressure to maintain the selectivity of pyruvate kinase activity for K+. Thus, we explored if the replacement of Thr113 by Leu alters the characteristics of the K+ binding site. We found that the polarity of the residue 113 is central in the partition of K+ into its site and that the substitution of Thr for Leu changes the ion selectivity for the monovalent cation with minor changes in the binding of the substrates. Therefore, Thr113 is instrumental in the selectivity of pyruvate kinase for K+. View Full-Text

Keywords: pyruvate kinase; K+; ion selectivity; monovalent cation; hydrophobicity; site-directed mutagenesis pyruvate kinase; K+; ion selectivity; monovalent cation; hydrophobicity; site-directed mutagenesis





Autor: Leticia Ramírez-Silva 1,* , Carlos Guerrero-Mendiola 1 and Nallely Cabrera 2

Fuente: http://mdpi.com/



DESCARGAR PDF




Documentos relacionados