INVESTIGADORES
PINONI Silvina Andrea
artículos
Título:
Partial characterization and response upon hyperegulating conditions of Na+-K+ ATPase and levamisole-sensitive Alkaline Phosphatase activities in chela muscle of the euryhaline crab Cyrtograpsus angulatus
Autor/es:
PINONI, S.A., LÓPEZ MAÑANES
Revista:
SCIENTIA MARINA
Editorial:
Scient. ed.: J.B. Company.
Referencias:
Lugar: Barcelona; Año: 2008 vol. 72 p. 15 - 24
ISSN:
0214-8358
Resumen:
The occurrence, characteristics and response to changes in environmental salinity of Na+-K+ AT Pase and
levamisole-sensitive alkaline phosphatase (AP) activities were studied in chela muscle of the euryhaline crab Cyrtograpsus
angulatus. Chela muscle exhibited an Na+-K+ AT Pase activity which was strongly dependent on AT P concentration, pH and
temperature of the reaction mixture. Maximal activity was found at 1 mM AT P, 30-37ºC and pH 7.4. Levamisole-sensitive
AP activity was characterised at physiological pH 7.4 and at pH 8.0. I50 for levamisole-sensitive AP activity was 8.8 mM
and 8.0 mM at pH 7.4 and 8.0, respectively. At both pH levels, levamisole-sensitive AP activity exhibited Michaelis-Menten
kinetics (Km=3.451 mM and 6.906 mM at pH 7.4 and 8.0, respectively). Levamisole-sensitive AP activities were strongly
affected by temperature, exhibiting a peak at 37ºC. In crabs acclimated to low salinity (10; hyperegulating conditions), Na+-
K+ AT Pase activity and levamisole-sensitive AP activity at the physiological pH were higher than in 35 psu (osmoconforming
conditions). The response to low salinity suggests that both activities could be components of muscle regulatory mechanisms
at the biochemical level secondary to hyperegulation of C. angulatus. The study of these activities under hyperegulating
conditions contributes to a better understanding of the complexity of biochemical mechanisms underlying the adaptive
process of euryhaline crabs.+-K+ AT Pase and
levamisole-sensitive alkaline phosphatase (AP) activities were studied in chela muscle of the euryhaline crab Cyrtograpsus
angulatus. Chela muscle exhibited an Na+-K+ AT Pase activity which was strongly dependent on AT P concentration, pH and
temperature of the reaction mixture. Maximal activity was found at 1 mM AT P, 30-37ºC and pH 7.4. Levamisole-sensitive
AP activity was characterised at physiological pH 7.4 and at pH 8.0. I50 for levamisole-sensitive AP activity was 8.8 mM
and 8.0 mM at pH 7.4 and 8.0, respectively. At both pH levels, levamisole-sensitive AP activity exhibited Michaelis-Menten
kinetics (Km=3.451 mM and 6.906 mM at pH 7.4 and 8.0, respectively). Levamisole-sensitive AP activities were strongly
affected by temperature, exhibiting a peak at 37ºC. In crabs acclimated to low salinity (10; hyperegulating conditions), Na+-
K+ AT Pase activity and levamisole-sensitive AP activity at the physiological pH were higher than in 35 psu (osmoconforming
conditions). The response to low salinity suggests that both activities could be components of muscle regulatory mechanisms
at the biochemical level secondary to hyperegulation of C. angulatus. The study of these activities under hyperegulating
conditions contributes to a better understanding of the complexity of biochemical mechanisms underlying the adaptive
process of euryhaline crabs.Cyrtograpsus
angulatus. Chela muscle exhibited an Na+-K+ AT Pase activity which was strongly dependent on AT P concentration, pH and
temperature of the reaction mixture. Maximal activity was found at 1 mM AT P, 30-37ºC and pH 7.4. Levamisole-sensitive
AP activity was characterised at physiological pH 7.4 and at pH 8.0. I50 for levamisole-sensitive AP activity was 8.8 mM
and 8.0 mM at pH 7.4 and 8.0, respectively. At both pH levels, levamisole-sensitive AP activity exhibited Michaelis-Menten
kinetics (Km=3.451 mM and 6.906 mM at pH 7.4 and 8.0, respectively). Levamisole-sensitive AP activities were strongly
affected by temperature, exhibiting a peak at 37ºC. In crabs acclimated to low salinity (10; hyperegulating conditions), Na+-
K+ AT Pase activity and levamisole-sensitive AP activity at the physiological pH were higher than in 35 psu (osmoconforming
conditions). The response to low salinity suggests that both activities could be components of muscle regulatory mechanisms
at the biochemical level secondary to hyperegulation of C. angulatus. The study of these activities under hyperegulating
conditions contributes to a better understanding of the complexity of biochemical mechanisms underlying the adaptive
process of euryhaline crabs.. Chela muscle exhibited an Na+-K+ AT Pase activity which was strongly dependent on AT P concentration, pH and
temperature of the reaction mixture. Maximal activity was found at 1 mM AT P, 30-37ºC and pH 7.4. Levamisole-sensitive
AP activity was characterised at physiological pH 7.4 and at pH 8.0. I50 for levamisole-sensitive AP activity was 8.8 mM
and 8.0 mM at pH 7.4 and 8.0, respectively. At both pH levels, levamisole-sensitive AP activity exhibited Michaelis-Menten
kinetics (Km=3.451 mM and 6.906 mM at pH 7.4 and 8.0, respectively). Levamisole-sensitive AP activities were strongly
affected by temperature, exhibiting a peak at 37ºC. In crabs acclimated to low salinity (10; hyperegulating conditions), Na+-
K+ AT Pase activity and levamisole-sensitive AP activity at the physiological pH were higher than in 35 psu (osmoconforming
conditions). The response to low salinity suggests that both activities could be components of muscle regulatory mechanisms
at the biochemical level secondary to hyperegulation of C. angulatus. The study of these activities under hyperegulating
conditions contributes to a better understanding of the complexity of biochemical mechanisms underlying the adaptive
process of euryhaline crabs.50 for levamisole-sensitive AP activity was 8.8 mM
and 8.0 mM at pH 7.4 and 8.0, respectively. At both pH levels, levamisole-sensitive AP activity exhibited Michaelis-Menten
kinetics (Km=3.451 mM and 6.906 mM at pH 7.4 and 8.0, respectively). Levamisole-sensitive AP activities were strongly
affected by temperature, exhibiting a peak at 37ºC. In crabs acclimated to low salinity (10; hyperegulating conditions), Na+-
K+ AT Pase activity and levamisole-sensitive AP activity at the physiological pH were higher than in 35 psu (osmoconforming
conditions). The response to low salinity suggests that both activities could be components of muscle regulatory mechanisms
at the biochemical level secondary to hyperegulation of C. angulatus. The study of these activities under hyperegulating
conditions contributes to a better understanding of the complexity of biochemical mechanisms underlying the adaptive
process of euryhaline crabs.m=3.451 mM and 6.906 mM at pH 7.4 and 8.0, respectively). Levamisole-sensitive AP activities were strongly
affected by temperature, exhibiting a peak at 37ºC. In crabs acclimated to low salinity (10; hyperegulating conditions), Na+-
K+ AT Pase activity and levamisole-sensitive AP activity at the physiological pH were higher than in 35 psu (osmoconforming
conditions). The response to low salinity suggests that both activities could be components of muscle regulatory mechanisms
at the biochemical level secondary to hyperegulation of C. angulatus. The study of these activities under hyperegulating
conditions contributes to a better understanding of the complexity of biochemical mechanisms underlying the adaptive
process of euryhaline crabs.+-
K+ AT Pase activity and levamisole-sensitive AP activity at the physiological pH were higher than in 35 psu (osmoconforming
conditions). The response to low salinity suggests that both activities could be components of muscle regulatory mechanisms
at the biochemical level secondary to hyperegulation of C. angulatus. The study of these activities under hyperegulating
conditions contributes to a better understanding of the complexity of biochemical mechanisms underlying the adaptive
process of euryhaline crabs.+ AT Pase activity and levamisole-sensitive AP activity at the physiological pH were higher than in 35 psu (osmoconforming
conditions). The response to low salinity suggests that both activities could be components of muscle regulatory mechanisms
at the biochemical level secondary to hyperegulation of C. angulatus. The study of these activities under hyperegulating
conditions contributes to a better understanding of the complexity of biochemical mechanisms underlying the adaptive
process of euryhaline crabs.C. angulatus. The study of these activities under hyperegulating
conditions contributes to a better understanding of the complexity of biochemical mechanisms underlying the adaptive
process of euryhaline crabs.