Dynamic Force Spectroscopy of the Specific Interaction between the PDZ Domain and Its Recognition Peptides
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- 作者：Tei Maki ; Satoru Kidoaki ; Kengo Usui ; Harukazu Suzuki ; Masayoshi Ito ; Fuyu Ito ; Yoshihide Hayashizaki ; Takehisa Matsuda
- 刊名：Langmuir
- 出版年：2007
- 出版时间：February 27, 2007
- 年：2007
- 卷：23
- 期：5
- 页码：2668 - 2673
- 全文大小：191K
- 年卷期：v.23,no.5(February 27, 2007)
- ISSN：1520-5827
文摘
To characterize the molecular basis of specific interactions of PDZ proteins, dynamic force spectroscopy (DFS)for the PDZ protein Tax-interacting protein-1 (TIP-1) and its recognition peptide (PDZ-pep) derived from 
-cateninwas performed using an atomic force microscope (AFM), together with measurement of thermodynamic and kineticparameters using surface plasmon resonance (SPR). The unbinding force of this pair was measured under differentconditions of AFM tip-retraction velocity. The relationship between the unbinding force and the logarithmic force-loading rate, that is, the dynamic force spectrum, exhibited two different rate regimes, for each of which the forcesincreased linearly with the force-loading rate. On the basis of the theoretical treatment of the Bell-Evans model, thepositions of two different activation barriers in the reaction coordinate and dissociation rate constants in each barrierwere evaluated from slopes and x-intercepts of the two linear regimes (first barrier: 0.04 nm and 1.10 × 10 s-1; secondbarrier: 0.21 nm and 2.77 × 10-2 s-1, respectively). Although two-step unbinding kinetics between TIP-1 andPDZ-pep was suggested from the DFS analysis, SPR results showed single-step dissociation kinetics with a rateconstant of 2.89 × 10-1 s-1. Different shapes of the free energy profile of the unbinding process were deduced fromeach result of DFS and SPR. The reason for such topographic differences in the energy landscape is discussed inrelation to the differences in the pathways of forced unbinding and spontaneous dissociation.
-cateninwas performed using an atomic force microscope (AFM), together with measurement of thermodynamic and kineticparameters using surface plasmon resonance (SPR). The unbinding force of this pair was measured under differentconditions of AFM tip-retraction velocity. The relationship between the unbinding force and the logarithmic force-loading rate, that is, the dynamic force spectrum, exhibited two different rate regimes, for each of which the forcesincreased linearly with the force-loading rate. On the basis of the theoretical treatment of the Bell-Evans model, thepositions of two different activation barriers in the reaction coordinate and dissociation rate constants in each barrierwere evaluated from slopes and x-intercepts of the two linear regimes (first barrier: 0.04 nm and 1.10 × 10 s-1; secondbarrier: 0.21 nm and 2.77 × 10-2 s-1, respectively). Although two-step unbinding kinetics between TIP-1 andPDZ-pep was suggested from the DFS analysis, SPR results showed single-step dissociation kinetics with a rateconstant of 2.89 × 10-1 s-1. Different shapes of the free energy profile of the unbinding process were deduced fromeach result of DFS and SPR. The reason for such topographic differences in the energy landscape is discussed inrelation to the differences in the pathways of forced unbinding and spontaneous dissociation.