Abstract
Membrane fragments from high potassium (HK) and low potassium (LK) sheep red cells were separated by density gradient centrifugation. Three preparations were studied: (1) HK membranes sonicated for 20 minutes, (2) HK membranes sonicated for 3 minutes, and (3) LK membranes sonicated for 3 minutes. The adenosine triphosphatase (ATPase) activity in the maximally disrupted preparation (1) was not sensitive to Na + K and was recovered in relatively small but heavy (specific gravity 1.19) fragments which made up no more than 8 per cent of the total membrane. Both Na + K-sensitive (S) and Na + K-insensitive (I) ATPase activity were found in the more gently broken up preparations (2) and (3) but the ratio of S- to I-ATPase was much greater in HK than in LK membrane fragments. S-ATPase activity in preparation (2) was about 50 per cent that observed in HK membranes prior to sonication. S-ATPase activity was recovered from the density gradient in relatively large but light (specific gravity 1.10) fragments. As was the case with the maximally disrupted preparation (1), I-ATPase activity in both preparations (2) and (3) was recovered in small but heavy (specific gravity > 1.20) fragments. The possibility that sensitivity of sheep red cell membrane ATPase to Na + K depends on the association between units containing the enzyme(s) and large, light, phospholipid-containing components is discussed.
Full Text
The Full Text of this article is available as a PDF (1.2 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BARTLETT G. R. Phosphorus assay in column chromatography. J Biol Chem. 1959 Mar;234(3):466–468. [PubMed] [Google Scholar]
- COHEN B. L., EVANS J. V., HARRIS H., KING J. W., WARREN F. L. Genetics of haemoglobin and blood potassium differences in sheep. Nature. 1956 Oct 20;178(4538):849–850. doi: 10.1038/178849a0. [DOI] [PubMed] [Google Scholar]
- DUNHAM E. T., GLYNN I. M. Adenosinetriphosphatase activity and the active movements of alkali metal ions. J Physiol. 1961 Apr;156:274–293. doi: 10.1113/jphysiol.1961.sp006675. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HILLIER J., HOFFMAN J. F. On the ultrastructure of the plasma membrane as determined by the electron microscope. J Cell Physiol. 1953 Oct;42(2):203–247. doi: 10.1002/jcp.1030420205. [DOI] [PubMed] [Google Scholar]
- POST R. L., MERRITT C. R., KINSOLVING C. R., ALBRIGHT C. D. Membrane adenosine triphosphatase as a participant in the active transport of sodium and potassium in the human erythrocyte. J Biol Chem. 1960 Jun;235:1796–1802. [PubMed] [Google Scholar]
- SKOU J. C. The influence of some cations on an adenosine triphosphatase from peripheral nerves. Biochim Biophys Acta. 1957 Feb;23(2):394–401. doi: 10.1016/0006-3002(57)90343-8. [DOI] [PubMed] [Google Scholar]
- TOSTESON D. C. Active transport, genetics, and cellular evolution. Fed Proc. 1963 Jan-Feb;22:19–26. [PubMed] [Google Scholar]
- TOSTESON D. C., HOFFMAN J. F. Regulation of cell volume by active cation transport in high and low potassium sheep red cells. J Gen Physiol. 1960 Sep;44:169–194. doi: 10.1085/jgp.44.1.169. [DOI] [PMC free article] [PubMed] [Google Scholar]
- WHITTAM R. The asymmetrical stimulation of a membrane adenosine triphosphatase in relation to active cation transport. Biochem J. 1962 Jul;84:110–118. doi: 10.1042/bj0840110. [DOI] [PMC free article] [PubMed] [Google Scholar]