Inhibition of hexokinase activity by a fructose 2,6-Bisphosphate-dependent cytosolic protein from liver
Author
dc.contributor.author
Niemeyer, Hermann
Author
dc.contributor.author
Cerpa, Carlos
Author
dc.contributor.author
Rabajille, Eliana
Admission date
dc.date.accessioned
2018-12-20T14:08:22Z
Available date
dc.date.available
2018-12-20T14:08:22Z
Publication date
dc.date.issued
1987
Cita de ítem
dc.identifier.citation
Archives of Biochemistry and Biophysics, Volumen 257, Issue 1, 2018, Pages 17-26
Identifier
dc.identifier.issn
10960384
Identifier
dc.identifier.issn
00039861
Identifier
dc.identifier.other
10.1016/0003-9861(87)90538-8
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/154199
Abstract
dc.description.abstract
Mammalian and yeast hexokinases were found to be reversibly inhibited by fructose 2,6-bisphosphate, an effect requiring the presence of a cytosolic protein factor. Experimental evidence suggests that this factor (inhibitor) is a regulatory protein, the interactions of which with hexokinases are modulated by fructose 2,6-bisphosphate. The Vmax of hexokinase D was decreased, and no changes on other kinetic parameters were observed. The inhibitor was present in fresh liver cytosol filtered through Sephadex G-25 and was partially isolated by negative absorption on DEAE-cellulose followed by ammonium sulfate fractionation. The inhibitor was also present in brain and kidney, but not in muscle. A molecular mass of 200,000 was determined by gel filtration. The inhibition was dependent on the concentrations of both the inhibitory protein and fructose 2,6-bisphosphate. No delay in fructose 2,6-bisphosphate inhibition was observed. Several other hexose phosphates were tested and were not effectiv