The Ca2+sensitivity of the actin‐activated ATPase of scallop heavy meromyosin
The Ca2+sensitivity of the actin‐activated ATPase of scallop heavy meromyosin
复制标题
扇贝重肌球蛋白肌动蛋白激活的 ATP 酶对 Ca2+ 的敏感性
DOI：
10.1016/0014-5793(84)80258-6
复制
发表时间：
1984
期刊：
影响因子：
3.5
通讯作者：
Clive R. Bagshaw
中科院分区：
文献类型：
--
作者：
C. Wells;Clive R. Bagshaw
The actin‐activated scallop heavy meromyosin (HMM) ATPase was monitored turbidometrically during a limited number of turnovers. At 4 μM actin, the turnover rate in the presence of Ca2+(1.2 s−1per head) was 650‐fold higher than in its absence (1.8 × 10−3s−1), a Ca2+sensitivity which approaches that expected in vivo. The extent of Ca2+activation was much larger than the observed by steady‐state measurements, where the rate, in the absence of Ca2+, is dominated by a small proportion of unregulated molecules. Acto‐HMM formation, and its dissociation by ATP, were Ca2+insensitive.
