ISSN: 2165-8056
Laboratorio de Fisiología, Facultad de Ciencias, Universidad de los Andes, Mérida, Venezuela
Research Article
Characterization of Glucokinase-1 from Phytophthora infestans: A Versatile Enzyme
Author(s): Liara Villalobos-Piña, Hermes Balza, Héctor Acosta*, Diego Andrade-Alviárez, Ascanio Rojas, Luisana Avilán and Amaranta Gómez-Arreaza
Phytophthora infestans has seven genes coding for glucokinases, with the [PITG_06016] (PiGlcK-1) gene being the highest expression at different stages of growth. However, its role in the metabolism of P. infestans is still unclear. In this study we cloned, overexpressed, purified and biochemically characterized this enzyme. The purified recombinant protein has a Km of 0.66 mM and 2.2 mM for glucose and ATP, respectively. PiGlcK-1 is capable of phosphorylating fructose, although only 48% with respect to glucose, using ADP and pyrophosphate (PPi) as a phosphoryl group donor. These molecules are 50% and 11% less effective than ATP, respectively. In addition, PiGlcK-1 can be activated by PPi increasing its activity 3.6 or 2.5 times when the phosphoryl donor is ATP or ADP, respectively. PiGlcK-1 can form oligomeric complexes and these tend to spontaneously dissoc.. View More»