De novo design of native proteins: Characterization of proteins intended to fold into antiparallel, rop-like, four-helix bundles
De novo design of native proteins: Characterization of proteins intended to fold into antiparallel, rop-like, four-helix bundles
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DOI：
10.1021/bi961704h
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发表时间：
1997-03-04
期刊：
影响因子：
2.9
通讯作者：
DeGrado, WF
中科院分区：
文献类型：
--
作者：
Betz, SF;Liebman, PA;DeGrado, WF
描述了一系列51个残基的螺旋-转角螺旋多肽的从头设计和表征，这些多肽旨在二聚成反平行的四股螺旋卷曲。该序列基于卷曲的七塔重复N-cap-(A(a)Z(b)Z(c)L(d)Z(e)Z(f)Z(g))(3)-turn-(X(a)Z(b)Z(c)L(d)Z(e)Z(f)Z(g))(3)-C-cap-CONH2，，其中X是Val或Ala。整个拓扑结构旨在与在大肠杆菌蛋白ROP中发现的相似。设计策略包括考虑疏水核心内侧链填充的几何互补性以及使用特定的界面相互作用，这两者都旨在有利于所需的POP-like拓扑结构。此外，该序列的设计是为了破坏可能与所需拓扑竞争的潜在替代结构的稳定性。这些多肽(RLP-1、RLP-2和RLP-3)组装成稳定的α-螺旋二聚体，并根据其光谱特性以及缺乏与疏水染料的结合而显示出天然蛋白质的特征。此外，还通过测量CD光谱的温度依赖性确定了变性时的热容和热容变化，并用差示扫描量热法(DSC)证实了这一点。用这两种方法测定的值非常一致，并且在这种大小的自然产生的蛋白质的范围内。这些结果表明，现在有可能设计类似天然的螺旋蛋白，作为进一步设计功能蛋白的模板。
The de novo design and characterization of a series of 51-residue helix-turn-helix peptides intended to dimerize into antiparallel four-stranded coiled coils is described. The sequence is based on a coiled coil heptad repeat N-cap-(A(a)Z(b)Z(c)L(d)Z(e)Z(f)Z(g))(3)-turn-(X(a)Z(b)Z(c)L(d)Z(e)Z(f)Z(g))(3)-C-cap-CONH2, where X is either Val or Ala. The overall topology was intended to be similar to that found in the Escherichia coli protein ROP. The design strategy included consideration of geometric complementarity of the packing of side chains within the hydrophobic core as well as the use of specific interfacial interactions, both of which were intended to favor the desired POP-like topology. Additionally, the sequence was designed to destabilize potential alternative structures that might compete with the desired topology. The peptides (RLP-1, RLP-2, and RLP-3) assemble into stable alpha-helical dimers and exhibit the hallmarks of a native protein as judged by its spectroscopic properties, and the lack of binding to hydrophobic dyes. Also, the enthalpy and heat capacity changes upon denaturation were determined by measuring the temperature dependence of the CD spectra and confirmed by differential scanning calorimetry (DSC). The values determined by the two methods are in excellent agreement and are in the range of these of naturally occurring proteins of this size. These results suggest that it is now possible to design native-like helical proteins that should serve as templates for the further design of functional proteins.