The effect of sodium periodate treatment on the modulation of the sodium pump in low-potassium type (LK) sheep red cells by the L antigen

1987 ◽  
Vol 904 (2) ◽  
pp. 330-336 ◽  
Author(s):  
Janet M. Stein ◽  
J.Clive Ellory ◽  
Elizabeth M. Tucker
Keyword(s):  
Sodium Pump ◽  
Sodium Periodate ◽  
Red Cells ◽  
Sheep Red Cells ◽  
Periodate Treatment ◽  
Low Potassium

scholarly journals Active Sodium and Potassium Transport in High Potassium and Low Potassium Sheep Red Cells

1971 ◽  
Vol 58 (4) ◽  
pp. 438-466 ◽  
Author(s):  
P. G. Hoffman ◽  
D. C. Tosteson
Keyword(s):  
Cell Types ◽  
Red Cells ◽  
Kinetic Characteristics ◽  
High Potassium ◽  
Cation Composition ◽  
Sheep Red Cells ◽  
Pump Rate ◽  
Low Potassium ◽  
K Transport ◽  
External K

The kinetic characteristics of the ouabain-sensitive (Na + K) transport system (pump) of high potassium (HK) and low potassium (LK) sheep red cells have been investigated. In sodium medium, the curve relating pump rate to external K is sigmoid with half maximal stimulation (K1/2) occurring at 3 mM for both cell types, the maximum pump rate in HK cells being about four times that in LK cells. In sodium-free media, both HK and LK pumps are adequately described by the Michaelis-Menten equation, but the K1/2 for HK cells is 0.6 ± 0.1 mM K, while that for LK is 0.2 ± 0.05 mM K. When the internal Na and K content of the cells was varied by the PCMBS method, it was found that the pump rate of HK cells showed a gradual increase from zero at very low internal Na to a maximum when internal K was reduced to nearly zero (100% Na). In LK cells, on the other hand, no pump activity was detected if Na constituted less than 70% of the total (Na + K) in the cell. Increasing Na from 70 to nearly 100% of the internal cation composition, however, resulted in an exponential increase in pump rate in these cells to about ⅙ the maximum rate observed in HK cells. While changes in internal composition altered the pump rate at saturating concentrations of external K, it had no effect on the apparent affinity of the pumps for external K. These results lead us to conclude that the individual pump sites in the HK and LK sheep red cell membranes must be different. Moreover, we believe that these data contribute significantly to defining the types of mechanism which can account for the kinetic characteristics of (Na + K) transport in sheep red cells and perhaps in other systems.

Identification of a 25 kDa polypeptide associated with the L antigen in low potassium-type sheep red cells

1990 ◽  
Vol 1022 (3) ◽  
pp. 408-410 ◽  
Author(s):  
Steven J. Pittman ◽  
J.Clive Ellory ◽  
Elizabeth M. Tucker ◽  
Christopher I. Newbold
Keyword(s):  
Red Cells ◽  
Sheep Red Cells ◽  
Low Potassium

Interaction of L antibody with low potassium-type sheep red cells: Resolution of two separate functional antibodies

1982 ◽  
Vol 64 (3) ◽  
pp. 167-174 ◽  
Author(s):  
C. E. Smalley ◽  
E. M. Tucker ◽  
P. B. Dunham ◽  
J. C. Ellory
Keyword(s):  
Red Cells ◽  
Sheep Red Cells ◽  
Low Potassium ◽  
Functional Antibodies

The number and specificity of L antigen sites on low potassium type sheep red cells

1976 ◽  
Vol 194 (1115) ◽  
pp. 271-277 ◽  
Keyword(s):  
Electron Microscopy ◽  
Potassium Transport ◽  
Red Cells ◽  
Sheep Red Cells ◽  
Transport Studies ◽  
Low Potassium

Pig anti-sheep IgG conjugated, to haemocyanin was used as a marker to visualize by electron microscopy the L and. M antigen sites on sheep red cells. The number of sites seen correlated well with the results of serological and potassium transport studies and supported the concept that there are qualitative as well as quantitative differences in the expression of L antigen on the membrane of LK type cells. A tentative estimate of 340 L p sites on homozygous LK and 120 on heterozygous LK cells was made.

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