Cooperative structural change of actin filaments interacting with activated myosin motor domain, detected with copolymers of pyrene-labeled actin and acto-S1 chimera protein
Cooperative structural change of actin filaments interacting with activated myosin motor domain, detected with copolymers of pyrene-labeled actin and acto-S1 chimera protein
复制标题
DOI：
10.1016/j.bbrc.2005.09.159
复制
发表时间：
2005-12-02
影响因子：
3.1
通讯作者：
Suzuki, M
中科院分区：
文献类型：
--
作者：
Siddique, MSP;Mogami, G;Suzuki, M
Acto-SI嵌合蛋白CP 24和CP 18携带插入网囊藻肌球蛋白11的运动域的环2中的整个肌动蛋白序列，并且具有接近于天然网囊藻肌动球蛋白的MaATP酶活性[M. S. P. Siddique，T.宫崎，E.片山，T. Q. P. Uyeda。M.铃木，肌动蛋白亚结构域I在肌动球蛋白滑动运动中的基本作用的证据，生物化学，生物物理。通信资源332（2005）474-481]。在这里，我们研究和检测协同结构变化的肌动蛋白丝伴随的相互作用与肌球蛋白马达结构域在ATP的存在下，使用共聚物丝组成的芘标记的骨骼肌动蛋白（SA）和CP 24或CP 18。加入ATP后，使用365- nm激发，荧光强度在380至480 nm范围内增加。对于CP 24与肌动蛋白的摩尔比为0.0625、0.143和0.333的共聚物长丝，在390 nm处荧光强度的相对增加分别为14%、46%和77%，并且表现出S形行为。化学计量分析表明，在SA-CP 24共聚物中，每个CP 24分子似乎平均影响四个肌动蛋白分子，并且在SA-CP 18共聚物中，每个CP IS分子似乎影响三个肌动蛋白分子。(c)2005年爱思唯尔公司All rights reserved.
Acto-SI chimera proteins CP24 and CP18 carry the entire actin sequence, inserted in loop 2 of the motor domain of Dictyostelium myosin 11, and have MaATPase activity close to that of natural Diciryostelium actomyosin [M.S.P. Siddique, T. Miyazaki, E. Katayama, T.Q.P. Uyeda. M. Suzuki, Evidence against essential roles Of subdomain I of actin in actomyosin sliding movements, Biochem. Biophys. Res. Commun. 332 (2005) 474-481]. Here, we examined and detected cooperative structural change of actin filaments accompanying interaction with myosin motor domain in the presence of ATP using copolymer filaments consisting of pyrene-labeled skeletal actin (SA) and either CP24 or CP18. Upon addition of ATP, the fluorescence intensity increased over the range from 380 to 480 nm using 365- nm excitation. The relative increases of fluorescence intensity at 390 run were 14%, 46%, and 77% for the copolymer Filaments with the CP24 to actin molar ratios of 0.0625, 0.143, and 0.333, respectively, and demonstrated a sigmoid behavior. Stoichiometric analysis indicates that each CP24 molecule appears to affect four actin molecules, on average, in SA-CP24 copolymers, and each CP IS molecule appears to affect three actin molecules in SA-CP18 copolymers. (c) 2005 Elsevier Inc. All rights reserved.