Irreversible thiophosphorylation and activation of tension in functionally skinned rabbit ileum strips by [35S]ATP gamma S.
Irreversible thiophosphorylation and activation of tension in functionally skinned rabbit ileum strips by [35S]ATP gamma S.
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[35S]ATP gamma S 对功能性去皮兔回肠条进行不可逆硫代磷酸化和张力激活。
DOI：
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发表时间：
1979
影响因子：
4.8
通讯作者：
W. Kerrick
中科院分区：
文献类型：
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作者：
P. Cassidy;P. E. Hoar;W. Kerrick
通过暴露于葡萄球菌α毒素，对兔回肠条进行功能性剥皮。在存在Ca 2+的情况下（但不存在Ca 2+的情况下），在ATP类似物ATP γ S或[35 S]ATP γ S中孵育条带导致最大Ca 2+不敏感的活化张力，该张力在去除Ca 2+后持续存在。与这种张力相关的是20，000-道尔顿肌球蛋白轻链LC 20的35 S标记，即使在去除Ca 2+后也持续存在。当暴露于ATP（α，β-亚甲基）时，这些条带中的张力部分放松。与此相反，α-毒素处理条暴露于ATP或[γ-32 P]ATP显示钙敏感，可逆的活化张力和可逆的32 P标记的LC 20。这些结果与目前提出的涉及肌球蛋白轻链激酶-磷酸酶系统的平滑肌收缩的Ca 2+控制模型是一致的。
Rabbit ileum strips were functionally skinned by exposure to staphylococcal alpha-toxin. Incubation of the strips in the ATP analog ATP gamma S or [35S]ATP gamma S in the presence of Ca2+ (but not in the absence of Ca2+) resulted in a maximal Ca2+-insensitive activated tension that persisted following removal of Ca2+. Correlated with this tension was 35S-labeling of the 20,000-dalton myosin light chain, LC20, that persisted even after removal of Ca2+. Tension in these strips partially relaxed when exposed to ATP (alpha,beta-methylene). In contrast, alpha-toxin-treated strips exposed to ATP or [gamma-32P]ATP showed Ca2+-sensitive, reversible activated tension and reversible 32P-labeling of the LC20. These results are consistent with a currently proposed model of Ca2+ control of smooth muscle contraction involving a myosin light chain kinase-phosphatase system.