The kinetic properties of the ecto-ATPase of human peripheral blood lymphocytes and of chronic lymphatic leukemia cells.
|
| Abstract |
This study examines whether the activity of the Mg2+-dependent ecto-ATPase of the surface membrane of the human lymphocyte is changed in chronic lymphocytic B-cell leukemia (CLL-B) and may be an indicator of malignant transformation. The ecto-ATPase activities of preparations consisting predominantly of T or B cells were compared to each other and to the ecto-ATPase of the CLL peripheral blood lymphocytes (PBL). The specific activities and kinetic constants of the ecto-ATPase of the cell preparations were determined with [gamma-32P] adenosine triphosphate (ATP) as substrate. B-enriched lymphocytes had nearly fourfold greater specific activity and apparent Vmax than T-enriched lymphocytes, while the Km values of both cell types showed no significant difference. The specific activities and kinetic constants of the ecto-ATPase of the CLL PBL were significantly higher than the corresponding values of PBL or of B-enriched lymphocytes. Judging from the kinetic constants the ecto-ATPase of the CLL-B lymphocyte appears to be an enzyme that is distinctly different from that of the normal B cell. On the basis of the kinetic properties, the ecto-ATPase of the B cell appears to be identical with that of the T cell. The differences in the maximal velocities of the hydrolysis of ATP by B and T cells are likely due to a greater number of enzymatic sites on the B cell.
|
|---|---|
| Authors | H R Gutmann, Y M Chow, R L Vessella, B Schuetzle, M E Kaplan |
| Journal | Blood (Blood) Vol. 62 Issue 5 Pg. 1041-6 (Nov 1983) ISSN: 0006-4971 [Print] United States |
| PMID | 6138109 (Publication Type: Comparative Study, Journal Article, Research Support, U.S. Gov't, Non-P.H.S.) |
| Chemical References |
|
| Topics |
|
Join CureHunter, for free Research Interface BASIC access!
Realize the full power of the drug-disease research graph!