PDF(Pubmed)
Abstract：
SLURP-1 is a three-finger human protein targeting nicotinic acetylcholine receptors (nAChRs). The recombinant forms of SLURP-1 produced in E. coli differ in added fusion fragments and in activity. The closest in sequence to the naturally occurring SLURP-1 is the recombinant rSLURP-1, differing by only one additional N-terminal Met residue. sSLURP-1 can be prepared by peptide synthesis and its amino acid sequence is identical to that of the natural protein. In view of recent NMR analysis of the conformational mobility of rSLURP-1 and cryo-electron microscopy structures of complexes of α-bungarotoxin (a three-finger snake venom protein) with Torpedo californica and α7 nAChRs, we compared conformations of sSLURP-1 and rSLURP-1 by Raman spectroscopy and CD-controlled thermal denaturation, analyzed their competition with α-bungarotoxin for binding to the above-mentioned nAChRs, compared the respective receptor complexes with computer modeling and compared their inhibitory potency on the α9α10 nAChR. The CD revealed a higher thermostability of sSLURP-1; some differences between sSLURP-1 and rSLURP-1 were observed in the regions of disulfides and tyrosine residues by Raman spectroscopy, but in binding, computer modeling and electrophysiology, the proteins were similar. Thus, sSLURP-1 and rSLURP-1 with only one additional Met residue appear close in structure and functional characteristics, being appropriate for research on nAChRs.
摘要：
SLURP-1是靶向烟碱乙酰胆碱受体(nAChRs)的三指人类蛋白质。在大肠杆菌中产生的SLURP-1的重组形式在添加的融合片段和活性方面不同。序列上最接近天然存在的SLURP-1的是重组rSLURP-1,其区别仅在于一个额外的N-末端Met残基。sSLURP-1可以通过肽合成来制备,并且其氨基酸序列与天然蛋白质的氨基酸序列相同。鉴于最近对rSLURP-1的构象迁移率和α-银环蛇毒素（三指蛇毒蛋白）与加利福尼亚鱼雷和α7nAChRs的复合物的低温电子显微镜结构的NMR分析，我们通过拉曼光谱和CD控制的热变性比较了sSLURP-1和rSLURP-1的构象，分析了它们与α-银环蛇毒素结合上述nAChR的竞争，通过计算机建模比较了各自的受体复合物，并比较了它们对α9α10nAChR的抑制效力。CD显示sSLURP-1具有较高的热稳定性；通过拉曼光谱在二硫化物和酪氨酸残基区域观察到sSLURP-1和rSLURP-1之间的一些差异，但是在绑定中，计算机建模和电生理学，蛋白质相似。因此，只有一个额外的Met残基的sSLURP-1和rSLURP-1在结构和功能特征上看起来很接近，适合研究nAChRs。
