Purification from Dictyostelium discoideum of a low-molecular-weight myosin that resembles myosin I from Acanthamoeba castellanii.
Purification from Dictyostelium discoideum of a low-molecular-weight myosin that resembles myosin I from Acanthamoeba castellanii.
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从盘基网柄菌中纯化出一种低分子量肌球蛋白，该肌球蛋白类似于来自卡氏棘阿米巴的肌球蛋白 I。
DOI：
10.1016/s0021-9258(18)89100-1
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
E. Korn
中科院分区：
文献类型：
--
作者：
G. Côté;J. Albanesi;T. Ueno;J. Hammer;E. Korn
一种低分子量肌球蛋白已从盘基网柄藻提取物中纯化了1500倍，基于K+，EDTA-ATP酶比活性的增加。纯化的酶类似于单头，低分子量肌球蛋白IA和IB从卡氏阿米巴，并不同于传统的双头，高分子量肌球蛋白以前从Dictyosteobacterium分离，在几个方面。其K+、EDTA-ATP酶活性高于Ca 2 +-ATP酶活性;其天然分子量约为150，000，单重链约为117，000; 117，000-道尔顿重链被阿米巴肌球蛋白I重链激酶磷酸化;其重链的磷酸化增强其肌动蛋白激活的Mg 2 +-ATP酶活性; 117，000-道尔顿重链与抗阿米巴肌球蛋白IA重链的抗体反应。这些特性都不被低分子量的活性片段所共享，该活性片段可以通过胰凝乳蛋白酶消化传统的网囊藻肌球蛋白而产生。我们的结论是，Dictyosteoblasts包含一种酶的肌球蛋白I型以前只从阿米巴分离。
A low-molecular-weight myosin has been purified 1500-fold from extracts of Dictyostelium discoideum, based on the increase in K+,EDTA-ATPase specific activity. The purified enzyme resembles the single-headed, low-molecular-weight myosins IA and IB from Acanthamoeba castellanii, and differs from the conventional two-headed, high-molecular-weight myosin previously isolated from Dictyostelium, in several ways. It has higher K+,EDTA-ATPase activity than Ca2+-ATPase activity; it has a native molecular mass of about 150,000 and a single heavy chain of about 117,000; the 117,000-dalton heavy chain is phosphorylated by Acanthamoeba myosin I heavy chain kinase; phosphorylation of its heavy chain enhances its actin-activated Mg2+-ATPase activity; and the 117,000-dalton heavy chain reacts with antibodies raised against the heavy chain of Acanthamoeba myosin IA. None of these properties is shared by the low-molecular-weight active fragment that can be produced by chymotryptic digestion of conventional Dictyostelium myosin. We conclude that Dictyostelium contains an enzyme of the myosin I type previously isolated only from Acanthamoeba.