Beck K, Gambee J E, Kamawal A, Bächinger H P
Shriners Hospital for Children, Research Unit, Portland, OR 97201, USA.
EMBO J. 1997 Jul 1;16(13):3767-77. doi: 10.1093/emboj/16.13.3767.
We have studied the oligomerization of an alpha-helical coiled-coil using as an example a peptide corresponding to the C-terminal domain of cartilage matrix protein. By replacing one arginine residue, which forms an interchain ionic interaction with a glutamic acid residue, with glutamine, we found that this peptide assembles into a homotetramer at neutral pH in contrast to the native molecule which forms homotrimers. At acidic and basic pH, however, we again observed the trimer conformation. Another arginine, which is probably involved in an intrachain salt bridge, has no effect on the assembly. Our data demonstrate that besides the specific distribution of hydrophobic residues, interchain ionic interactions can be crucial in modulating the association behavior of alpha-helical coiled-coil domains.
我们以对应于软骨基质蛋白C末端结构域的肽为例，研究了α-螺旋卷曲螺旋的寡聚化。通过用谷氨酰胺取代一个与谷氨酸残基形成链间离子相互作用的精氨酸残基，我们发现该肽在中性pH下组装成同四聚体，这与形成同三聚体的天然分子不同。然而，在酸性和碱性pH下，我们再次观察到三聚体构象。另一个可能参与链内盐桥形成的精氨酸对组装没有影响。我们的数据表明，除了疏水残基的特定分布外，链间离子相互作用在调节α-螺旋卷曲螺旋结构域的缔合行为中可能至关重要。
