Na+,K+-ATPase Activity in the Posterior Gills of the Blue Crab, Callinectes ornatus (Decapoda, Brachyura): Modulation of ATP Hydrolysis by the Biogenic Amines Spermidine and Spermine

作者：Garcon Daniela P; Lucena Malson N; Franca Juliana L; McNamara John C; Fontes Carlos F L; Leone Francisco A^*

来源：Journal of Membrane Biology, 2011, 244(1): 9-20.

DOI：10.1007/s00232-011-9391-5

• Na+,K+-ATPase modulation
• Posterior gill
• Polyamine
• Callinectes ornatus
• Kinetic analysis

We investigated the effect of the exogenous polyamines spermine, spermidine and putrescine on modulation by ATP, K+, Na+, NH4 (+) and Mg2+ and on inhibition by ouabain of posterior gill microsomal Na+,K+-ATPase activity in the blue crab, Callinectes ornatus, acclimated to a dilute medium (21aEuro degrees salinity). This is the first kinetic demonstration of competition between spermine and spermidine for the cation sites of a crustacean Na+,K+-ATPase. Polyamine inhibition is enhanced at low cation concentrations: spermidine almost completely inhibited total ATPase activity, while spermine inhibition attained 58%; putrescine had a negligible effect on Na+,K+-ATPase activity. Spermine and spermidine affected both V and K for ATP hydrolysis but did not affect ouabain-insensitive ATPase activity. ATP hydrolysis in the absence of spermine and spermidine obeyed Michaelis-Menten behavior, in contrast to the cooperative kinetics seen for both polyamines. Modulation of V and K by K+, Na+, NH4 (+) and Mg2+ varied considerably in the presence of spermine and spermidine. These findings suggest that polyamine inhibition of Na+,K+-ATPase activity may be of physiological relevance to crustaceans that occupy habitats of variable salinity.

• 出版日期2011-11