Localization of a phosphatase (ATPase) on the plasmalemma of the maize scutellum |
| |
Authors: | Heijia Wheeler Thomas Humphreys Henry Aldrich |
| |
Affiliation: | Departments of Botany and of Microbiology and Cell Science, Agricultural Experiment Station, University of Florida, Gainesville, FL 32611, U.S.A. |
| |
Abstract: | A phosphatase (ATPase) was demonstrated on the surface of the maize scutellum cell by showing that (1) when exogenous ATP was hydrolysed by intact scutellum cells, ADP, AMP and Pi appeared in the bathing solution in stoichiometric amounts, (2) the rate of hydrolysis was sensitive to bathing solution pH; (3) exogenous Mg2+ increased the rate of hydrolysis and (4) when the ATPase reaction was carried out in the presence of lead nitrate, TEM photographs showed lead phosphate deposits located almost exclusively in the plasmalemma. The ATPase was tightly bound to the plasmalemma and was not destroyed by freezing and thawing scutellum slices, a treatment which disrupted the plasmalemma. Acid treatment (10 mM HCl) of fresh or frozen-thawed scutellum slices destroyed acid phosphatase activity but had little effect on ATPase activity at pH 6.5. Following acid treatment of the scutellum slice preparations, a definite Mg2+ requirement for ATPase activity could be demonstrated. |
| |
Keywords: | Gramineae maize scutellum phosphatase ATPase plasmalemma. |
本文献已被 ScienceDirect 等数据库收录! |
|