Effects of interchain disulfide cross-links on the trypsin cleavage pattern and conformation of myosin subfragment 2.
Effects of interchain disulfide cross-links on the trypsin cleavage pattern and conformation of myosin subfragment 2.
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链间二硫键交联对胰蛋白酶切割模式和肌球蛋白亚片段2构象的影响。
DOI:
10.1021/bi00320a013
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发表时间:
1984
期刊:
影响因子:
2.9
通讯作者:
Lehrer,SS
中科院分区:
文献类型:
--
作者:
Lu,RC;Lehrer,SS
Renne Chen Lu* and Sherwin S. Lehrer* abstract: The ability of 5, 5/-dithiobis (2-nitrobenzoate)(Nbs2) to produce interchain disulfide cross-links in both the long and short forms of myosin subfragment 2 (S2) and the conformational effects of these cross-links have been inves-tigated. Short S2 (residues 3-287) containstwo pairs of Cys residues at positions 66 and 108, and long S2 (residues 1-440) contains an additional pair at position 410. The reaction kinetics of each form of S2 with Nbs2 was biphasic. During the fast kinetic phase the reaction resulted in un-cross-linked species having Nbs-blocked Cys. During the slowphase disulfide-cross-linked species were formed via interchain S-Nbs/SH exchange. For short S2, Cys-66 appeared to react without forming disulfidecross-links, and the Cys-108 pair reacted with partial cross-linking. For long S2, the Cys-66 pair appeared to react with partial cross-linking, and the Cys pairs at 108 and 410 reacted with complete cross-linking. MildEfach of the two heavy chains of the myosin molecule con-sists of an N-terminal globular head portion [SI, Afr (chain)~ 100 000] that contains the adenosinetriphosphatase (AT-Pase) and actin binding sites and a rodlike coiled-coil portion [rod, Mr (chain)~ 130 000], the C-terminal part of which [LMM, 1 Mt (chain)~ 70000] forms the core of the thick filament. Most current models of muscle contraction associate the force generation with one or more states which differs in the disposition of the heads relative to the rod (Huxley, 1969; Huxley & Simmons, 1971; Eisenberg et al., 1980). Another force-generating mechanism which has been suggested involves a conformational change in theS2 portion of the rod, ie, the portion between the heads and LMM (Harrington, 1971, 1979). Localized helix-coil transition (melting) inthe rod near the LMM-S2 junction has been interpreted as supporting this concept (Tsong et al., 1983; Swenson & Ritchie, 1980). Studies with tropomyosin, the prototype of a coiled-coil a-helical molecule, have produced evidence for regions of localized melting (Woods, 1969, 1976; Satoh & Mihashi, 1972; Chao & Holtzer, 1975; Lehrer, 1978; Graceffa & Lehrer,
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影响因子:
5.6
作者:
K. Sutoh;T. Karr;W. F. Harrington
通讯作者:
W. F. Harrington
影响因子:
2.9
作者:
Y. Chao;A. Holtzer
通讯作者:
A. Holtzer
DOI:
10.1016/s0021-9258(19)70290-7
发表时间:
1980-12
期刊:
The Journal of biological chemistry
影响因子:
--
作者:
P. Graceffa;S. Lehrer
通讯作者:
P. Graceffa;S. Lehrer
影响因子:
3.5
作者:
M. Stewart
通讯作者:
M. Stewart
影响因子:
--
作者:
R. Doolittle
通讯作者:
R. Doolittle