Abstract
1. 1. Branchial Na+ K+-ATPase specific activity is some 20% greater in hyposahne adapted Opsanus beta than in SW specimens. 2. 2. Ouabain insensitive ATPase (Mg2+-ATPase) specific activities were similar, while whole body-activity differences in low salinity and SW adapted fish could be accounted for by the 30% difference in extractable gill protein. 3. 3. NH4+ ion was 15% more effective at dephosphorylation of the microsomal Na-dependent phosphoenzyme than either Rb+ or K+. and revealed a maximal ATPase affinity (Km = 0.2 mM) within the physiological range of blood [K+]. 4. 4. Similar properties as pH optima, ATP and Mg2+ Km's. ouabain sensitivity, percent recoveries and subcell distribution indicated that the NH+4-stimulation acts through the Na+ K+ -ATPase carrier enzyme and may be resonsible for the Na+/NH+4 exchange in Opsanu beta.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 889-897 |
| Number of pages | 9 |
| Journal | Comparative Biochemistry and Physiology -- Part A: Physiology |
| Volume | 74 |
| Issue number | 4 |
| DOIs | |
| State | Published - Jan 1 1983 |
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ASJC Scopus subject areas
- Physiology
- Biochemistry
- Molecular Biology
Cite this
A carrier enzyme basis for ammonium excretion in teleost gill. NH+4-stimulated Na-dependent ATPase activity in Opsanus beta. / Mallery, Charles.
In: Comparative Biochemistry and Physiology -- Part A: Physiology, Vol. 74, No. 4, 01.01.1983, p. 889-897.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A carrier enzyme basis for ammonium excretion in teleost gill. NH+4-stimulated Na-dependent ATPase activity in Opsanus beta
AU - Mallery, Charles
PY - 1983/1/1
Y1 - 1983/1/1
N2 - 1. 1. Branchial Na+ K+-ATPase specific activity is some 20% greater in hyposahne adapted Opsanus beta than in SW specimens. 2. 2. Ouabain insensitive ATPase (Mg2+-ATPase) specific activities were similar, while whole body-activity differences in low salinity and SW adapted fish could be accounted for by the 30% difference in extractable gill protein. 3. 3. NH4+ ion was 15% more effective at dephosphorylation of the microsomal Na-dependent phosphoenzyme than either Rb+ or K+. and revealed a maximal ATPase affinity (Km = 0.2 mM) within the physiological range of blood [K+]. 4. 4. Similar properties as pH optima, ATP and Mg2+ Km's. ouabain sensitivity, percent recoveries and subcell distribution indicated that the NH+4-stimulation acts through the Na+ K+ -ATPase carrier enzyme and may be resonsible for the Na+/NH+4 exchange in Opsanu beta.
AB - 1. 1. Branchial Na+ K+-ATPase specific activity is some 20% greater in hyposahne adapted Opsanus beta than in SW specimens. 2. 2. Ouabain insensitive ATPase (Mg2+-ATPase) specific activities were similar, while whole body-activity differences in low salinity and SW adapted fish could be accounted for by the 30% difference in extractable gill protein. 3. 3. NH4+ ion was 15% more effective at dephosphorylation of the microsomal Na-dependent phosphoenzyme than either Rb+ or K+. and revealed a maximal ATPase affinity (Km = 0.2 mM) within the physiological range of blood [K+]. 4. 4. Similar properties as pH optima, ATP and Mg2+ Km's. ouabain sensitivity, percent recoveries and subcell distribution indicated that the NH+4-stimulation acts through the Na+ K+ -ATPase carrier enzyme and may be resonsible for the Na+/NH+4 exchange in Opsanu beta.
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UR - http://www.scopus.com/inward/citedby.url?scp=0020689505&partnerID=8YFLogxK
U2 - 10.1016/0300-9629(83)90364-X
DO - 10.1016/0300-9629(83)90364-X
M3 - Article
VL - 74
SP - 889
EP - 897
JO - Comparative Biochemistry & Physiology; A: Comparative Physiology
JF - Comparative Biochemistry & Physiology; A: Comparative Physiology
SN - 1095-6433
IS - 4
ER -