On the benefit of bivalency in peptide Ligand/Pin1 interactions
On the benefit of bivalency in peptide Ligand/Pin1 interactions
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DOI：
10.1016/j.jmb.2007.09.019
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发表时间：
2007-11-16
影响因子：
5.6
通讯作者：
Schiene-Fischer, Cordelia
中科院分区：
文献类型：
--
作者：
Daum, Sebastian;Luecke, Christian;Schiene-Fischer, Cordelia
人肽基脯氨酰顺式/反式异构酶（PPIase）Pin 1在发育过程和细胞增殖中起关键作用。Pin 1由N-末端WW结构域和C-末端催化PPIase结构域组成，两者均特异性靶向Ser（PO 3 H2）/Thr（PO 3 H2）-Pro序列。在这里，我们报告了增强的亲和力源自二价结合的配体对Pin 1相比，单价结合。我们开发了复合肽，其中N-末端片段代表催化定点基序，C-末端片段对由不同链长的聚脯氨酸连接子拴系的Pin 1的WW结构域表现出主要的亲和力。我们使用NMR位移扰动实验，以获得信息的特定相互作用的二价配体的两个目标网站的Pin 1。二价配体允许相当大的范围内的热力学研究，使用等温滴定量热法和PPIase活性测定。与单价肽相比，它们在纳摩尔范围内对Pin 1的亲和力提高了350倍。两个结合基序之间的距离与亲和力高度相关。活性位点和WW结构域定向肽片段之间的5个脯氨酰残基的接头长度所表现出的亲和力的最佳值表明，Pin 1中的相应结构域允许在配体结合后采用优选的空间排列。(c)2007爱思唯尔有限公司保留所有权利。
The human peptidyl prolyl cis/trans isomerase (PPIase) Pin1 has a key role in developmental processes and cell proliferation. Pin1 consists of an N-terminal WW domain and a C-terminal catalytic PPIase domain both targeted specifically to Ser(PO3H2)/Thr(PO3H2)-Pro sequences. Here, we report the enhanced affinity originating from bivalent binding of ligands toward Pin1 compared to monovalent binding. We developed composite peptides where an N-terminal segment represents a catalytic site-directed motif and a C-terminal segment exhibits a predominant affinity to the WW domain of Pin1 tethered by polyproline linkers of different chain length. We used NMR shift perturbation experiments to obtain information on the specific interaction of a bivalent ligand to both targeted sites of Pin1. The bivalent ligands allowed a considerable range of thermodynamic investigations using isothermal titration calorimetry and PPIase activity assays. They expressed up to 350-fold improved affinity toward Pin1 in the nanomolar range in comparison to the monovalent peptides. The distance between the two binding motifs was highly relevant for affinity. The optimum in affinity manifested by a linker length of five prolyl residues between active site- and WW domain-directed peptide fragments suggests that the corresponding domains in Pin1 are allowed to adopt preferred spatial arrangement upon ligand binding. (c) 2007 Elsevier Ltd. All rights reserved.