Heterooligomeric complexes of human small heat shock proteins
Heterooligomeric complexes of human small heat shock proteins
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DOI：
10.1007/s12192-011-0296-0
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发表时间：
2012-03-01
影响因子：
3.8
通讯作者：
Gusev, Nikolai B.
中科院分区：
文献类型：
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作者：
Mymrikov, Evgeny V.;Seit-Nebi, Alim S.;Gusev, Nikolai B.
用尺寸排斥层析、分析超速离心法和化学交联法分析了人小分子热休克蛋白HspB1、HspB5、HspB6和HspB8的寡聚结合。野生型HspB5、HspB6和HspB8的突变体HspB5、HspB6和HspB8在与人HspB1的Cys137同源的位置上含有一个Cys残基，能够产生以二硫键交联的异源二聚体。HspB1/HspB5、HspB1/HspB6和HspB5/HspB6之间的交联型杂二聚体在混合时很容易产生，而任何有HspB8参与的杂二聚体的形成效率都显著低于HspB8。HspB1/HspB6和HspB5/HspB6形成的杂寡体的大小与相应的同源低聚体的大小不同。小分子热休克蛋白的二硫键交联的同源二聚体不能参与异寡体的形成。因此，单体可以参与亚基交换，从而导致杂寡体的形成，而二硫键交联导致的灵活性限制阻止了亚基交换。
Oligomeric association of human small heat shock proteins HspB1, HspB5, HspB6 and HspB8 was analyzed by means of size-exclusion chromatography, analytical ultracentrifugation and chemical cross-linking. Wild-type HspB1 and Cys mutants of HspB5, HspB6 and HspB8 containing a single Cys residue in position homologous to that of Cys137 of human HspB1 were able to generate heterodimers cross-linked by disulfide bond. Cross-linked heterodimers between HspB1/HspB5, HspB1/HspB6 and HspB5/HspB6 were easily produced upon mixing, whereas formation of any heterodimers with participation of HspB8 was significantly less efficient. The size of heterooligomers formed by HspB1/HspB6 and HspB5/HspB6 was different from the size of the corresponding homooligomers. Disulfide cross-linked homodimers of small heat shock proteins were unable to participate in heterooligomer formation. Thus, monomers can be involved in subunit exchange leading to heterooligomer formation and restriction of flexibility induced by disulfide cross-linking prevents subunit exchange.