Isolated and distribution of myosin isoenzymes in chicken pectoralis muscle.
Isolated and distribution of myosin isoenzymes in chicken pectoralis muscle.
复制标题
鸡胸肌肌球蛋白同工酶的分离和分布。
DOI：
10.1016/0022-2836(81)90510-6
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发表时间：
1981
影响因子：
5.6
通讯作者：
Lowey,S
中科院分区：
文献类型：
--
作者：
Silberstein,L;Lowey,S
对鸡胸肌肌球蛋白的碱1（A1）和碱2（A2）轻链具有独特特异性的兔抗体的制备导致直接分离出两种同型二聚体的肌球蛋白：A1-肌球蛋白和A2-肌球蛋白，这两种分子在每个头部上含有相同的轻链。还推断存在含有A1和A2轻链的异二聚体物质。三种类型的碱性轻链同工酶在成年鸡胸肌中的含量大致相等。用改良的Farr法和固相放射免疫分析法以及抗体亲和层析法测定了抗体的特异性。由纯化抗体识别的肌球蛋白中的决定簇似乎仅限于碱性轻链的N-末端序列。由于这种狭窄的特异性，这些免疫学试剂可用于表征A1和A2在肌球蛋白分子内的分布，并将单个轻链定位在肌肉内。通过用荧光标记物标记抗体，我们已经表明A1和A2存在于每个肌原纤维内，以及存在于同一纤维内（Loweyet al.，1979年a）。此外，通过使用山羊抗兔免疫球蛋白来增强针对轻链的一抗的可视化，我们已经在电子显微镜中证明了A1和A2沿每个肌丝的长度沿着共存。这一观察结果表明，无论碱性轻链同工酶之间存在何种功能差异，它们都必须在单一细丝的约束下运作。
The preparation of rabbit antibodies uniquely specific for the alkali 1 (A1) and alkali 2 (A2) light chains of chicken pectoralis myosin has led to the direct isolation of two homodimeric species of myosin: A1-myosin and A2-myosin, molecules which contain the same light chain on each head. The existence of a heterodimeric species, containing both A1 and A2 light chains, was also inferred. The three types of alkali light chain isoenzymes occur in approximately equal amounts in adult chicken pectoralis muscle.The specificities of the antibodies were determined by modified Farr and solid phase radioimmunoassays, as well as by antibody-affinity chromatography. The determinants in myosin that are recognized by the purified antibodies appear to be confined to the N-terminal sequences of the alkali light chains. As a result of this narrow specificity, these immunological reagents can be used to characterize the distribution of A1 and A2 within the myosin molecule, and to localize the individual light chains within the muscle.By labeling the antibodies with a fluorescent marker we have shown that A1 and A2 are present within each myofibril, as well as within the same fiber (Loweyet al., 1979a). Moreover, by using goat anti-rabbit immunoglobulin to enhance the visualization of the primary antibodies against the light chains, we have demonstrated in the electron microscope that A1 and A2 co-exist along the length of each myofilament. This observation suggests that whatever functional differences may exist among the alkali light chain isoenzymes, they must operate within the constraints of a single filament.