| Full text | |
| Author(s): |
Leone, Francisco A.
;
Fabri, Leonardo M.
;
Costa, Maria I. C.
;
Moraes, Cintya M.
;
Garcon, Daniela P.
;
McNamara, John C.
Total Authors: 6
|
| Document type: | Journal article |
| Source: | COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-TOXICOLOGY & PHARMACOLOGY; v. 274, p. 11-pg., 2023-09-28. |
| Abstract | |
We used the gill (Na+, K+)-ATPase as a molecular marker to provide a comprehensive kinetic analysis of the effects of Co2+ in vitro on the modulation of K+-phosphatase activity in the Blue crab Callinectes danae. Co2+ can stimulate or inhibit K+-phosphatase activity. With Mg2+, K+-phosphatase activity is almost completely inhibited by Co2+. Co2+ stimulates K+-phosphatase activity similarly to Mg2+ although with a approximate to 4.5-fold greater affinity. At saturating Mg2+ concentrations, Mg2+ displaces bound Co2+ from the Mg2+-binding site in a concentration dependent manner, but Co2+ cannot displace Mg2+ from its binding site even at millimolar concentrations. Saturation by Co2+ of the Mg2+ binding site does not affect pNPP recognition by the enzyme. Substitution of Mg2+ by Co2+ slightly increases enzyme affinity for K+ and NH4+. Independently of Mg2+, inhibition by ouabain or sodium ions is unaffected by Co2+. Investigation of gill (Na+, K+)-ATPase K+-phosphatase activity provides a reliable tool to examine the kinetic effects of Co2+ with and without Na+ and ATP. Given that the toxic effects of Co2+ at the molecular level are poorly understood, these findings advance our knowledge of the mechanism of action of Co2+ on the crustacean gill (Na+, K+)-ATPase. (AU) | |
| FAPESP's process: | 16/25336-0 - Comparative biochemical study of gill (Na+, K +)- ATPase of Macrobrachium amazonicum (Heller, 1862) inhabitant of coastal and continental regions |
| Grantee: | Francisco de Assis Leone |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 19/21899-8 - Kinetic and molecular characterization of the gill (NA+, K+)-ATPase from Macrobrachium amazonicum inhabitants of the Mato Grosso Pantanal and Tocantins-Araguaia River Basin |
| Grantee: | Francisco de Assis Leone |
| Support Opportunities: | Regular Research Grants |