A Kinetic Characterization of the Gill (Na+, K+)-ATPase from the Semi-terrestrial Mangrove Crab Cardisoma guanhumi Latreille, 1825 (Decapoda, Brachyura)

Author(s)

Farias, Daniel L. ^[1] ; Lucena, Malson N. ^[1] ; Garcon, Daniela P. ^[2] ; Mantelatto, Fernando L. ^[3] ; McNamara, John C. ^{[3, 4]} ; Leone, Francisco A. ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Quim, Fac Filosofia Ciencias & Letras Ribeirao Preto, Ave Bandeirantes 3900, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Univ Fed Triangulo Mineiro, DPG, Campus Univ Iturama, BR-38280000 Iturama, MG - Brazil

^[3] Univ Sao Paulo, Dept Biol, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Ribeirao Preto, SP - Brazil

^[4] Ctr Biol Marinha, BR-11000600 Sao Sebastiao, SP - Brazil

• Document type: Journal article
• Source: Journal of Membrane Biology; v. 250, n. 5, p. 517-534, OCT 2017.
• Web of Science Citations: 1

Abstract

We provide a kinetic characterization of (Na+, K+)-ATPase activity in a posterior gill microsomal fraction from the semi-terrestrial mangrove crab Cardisoma guanhumi. Sucrose density gradient centrifugation reveals two distinct membrane fractions showing considerable (Na+, K+)-ATPase activity, but also containing other microsomal ATPases. The (Na+, K+)-ATPase, notably immuno-localized to the apical region of the epithelial pillar cells, and throughout the pillar cell bodies, has an M (r) of around 110 kDa and hydrolyzes ATP with V (M) = 146.8 +/- 6.3 nmol Pi min(-1) mg protein(-1) and K (M) = 0.05 +/- 0.003 mmol L-1 obeying Michaelis-Menten kinetics. While stimulation by Na+ (V (M) = 139.4 +/- 6.9 nmol Pi min(-1) mg protein(-1), K (M) = 4.50 +/- 0.22 mmol L-1) also follows Michaelis-Menten kinetics, modulation of (Na+, K+)-ATPase activity by MgATP (V (M) = 136.8 +/- 6.5 nmol Pi min(-1) mg protein(-1), K (0.5) = 0.27 +/- 0.04 mmol L-1), K+ (V (M) = 140.2 +/- 7.0 nmol Pi min(-1) mg protein(-1), K (0.5) = 0.17 +/- 0.008 mmol L-1), and NH4 (+) (V (M) = 149.1 +/- 7.4 nmol Pi min(-1) mg protein(-1), K (0.5) = 0.60 +/- 0.03 mmol L-1) shows cooperative kinetics. Ouabain (K (I) = 52.0 +/- 2.6 A mu mol L-1) and orthovanadate (K (I) = 1.0 +/- 0.05 A mu mol L-1) inhibit total ATPase activity by around 75%. At low Mg2+ concentrations, ATP is an allosteric modulator of the enzyme. This is the first study to provide a kinetic characterization of the gill (Na+, K+)-ATPase in C. guanhumi, and will be useful in better comprehending the biochemical underpinnings of osmoregulatory ability in a semi-terrestrial mangrove crab. (AU)

• FAPESP's process: 13/00976-8 - Kinetic and molecular characterization of the gill (Na+,K+)-ATPase of crab Cardisoma guanhumi (Latreille)
• Grantee: Daniel Lima de Farias
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 10/17534-0 - Role of (Na,K)-ATPase in osmoregulation and excretion of ammonium ions in euryhaline crustaceans: identification and influence of FXYD2 on the regulation of gill (Na,K)-ATPase of the crab Callinectes danae
• Grantee: Francisco de Assis Leone
• Support type: Regular Research Grants
• FAPESP's process: 13/24252-9 - The (Na+,K+)-ATPase in osmoregulatory capacity in crab Ucides cordatus: biochemical and molecular view
• Grantee: Malson Neilson de Lucena
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 13/22605-1 - Kinetic and molecular characterization of gill tissue (Na+,K+)-ATPase from Cardisoma guanhumi (Latreille)crab
• Grantee: Francisco de Assis Leone
• Support type: Regular Research Grants
• FAPESP's process: 10/50188-8 - Decapod crustaceans: multi-disciplinary characterization of the sea biodiversity of the State of São Paulo (taxonomy, spermiotaxonomy, molecular biology and population dynamics)
• Grantee: Fernando Luis Medina Mantelatto
• Support type: BIOTA-FAPESP Program - Thematic Grants