Ouabain sensitivity of the alpha 3 isozyme of rat Na,K-ATPase |
| |
Authors: | O Urayama K J Sweadner |
| |
Institution: | Neurosurgical Research, Massachusetts General Hospital, Boston 02114. |
| |
Abstract: | The Na,K-ATPase of rat brainstem axolemma membranes contains two isozymes of its catalytic subunit, alpha 2 and alpha 3. To isolate the alpha 3 isozyme functionally, purified axolemma Na,K-ATPase was treated with trypsin. Immunoblot analysis of trypsin-treated Na,K-ATPase using isozyme-specific antibodies showed that alpha 3 was significantly more resistant to digestion than alpha 2. The trypsin-resistant alpha 3 isozyme fraction, devoid of alpha 2, contained 50-60% of the ATPase activity, and was inhibited by ouabain half-maximally at 0.13 microM. This indicates that the alpha 3 Na,K-ATPase isozyme has a high sensitivity to cardiac glycosides. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|