Premium
Spontaneous subunit exchange in porcine liver fructose‐1,6‐bisphosphatase
Author(s) -
Nelson Scott W,
Honzatko Richard B,
Fromm Herbert J
Publication year - 2001
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(01)02262-1
Subject(s) - fructose 1,6 bisphosphatase , allosteric regulation , protein subunit , dimer , chemistry , fructose , biochemistry , enzyme , biophysics , biology , organic chemistry , gene
No evidence to date suggests the possibility of subunit exchange between tetramers of mammalian fructose‐1,6‐bisphosphatase. An engineered fructose‐1,6‐bisphosphatase, with subunits of altered electrostatic charge, exhibits spontaneous subunit exchange with wild‐type enzyme in the absence of ligands. The exchange process reaches equilibrium in approximately 5 h at 4°C, as monitored by non‐denaturing gel electrophoresis and anion exchange chromatography. Active site ligands, such as fructose 6‐phosphate, abolish subunit exchange at the level of the monomer, but permit dimer–dimer exchanges. AMP, alone or in the presence of active site ligands, abolishes all exchange processes. Exchange phenomena may play a role in the kinetic mechanism of allosteric regulation of fructose‐1,6‐bisphosphatase.