Kinetics and regulation of three cloned mammalian Na+/H+ exchangers stably expressed in a fibroblast cell line.
SA Levine, MH Montrose, CM Tse… - Journal of Biological …, 1993 - ASBMB
The kinetics and second messenger regulation of three cloned mammalian intestinal
Na+/H+ exchangers were studied using fluorometric techniques. These exchangers, NHE1,
NHE2, and NHE3, were stably expressed in PS120 fibroblasts, which lack an endogenous
Na+/H+ exchanger. H+ kinetic data indicated cooperativity by internal protons, with Hill
coefficients of approximately 2 for all three isoforms. In contrast, Na+ kinetic data fit Michaelis-
Menten kinetics, with Km (Na+) 15-18 mM and a Hill coefficient of approximately 1. The …
Na+/H+ exchangers were studied using fluorometric techniques. These exchangers, NHE1,
NHE2, and NHE3, were stably expressed in PS120 fibroblasts, which lack an endogenous
Na+/H+ exchanger. H+ kinetic data indicated cooperativity by internal protons, with Hill
coefficients of approximately 2 for all three isoforms. In contrast, Na+ kinetic data fit Michaelis-
Menten kinetics, with Km (Na+) 15-18 mM and a Hill coefficient of approximately 1. The …
