Method used to measure interaction of proteins with dual-beam optical tweezers.
In the force measurement of protein-protein interaction, proteins are usually attached to microbeads, so the coated beads serve as both handles and force transducers. Due to the short interaction distance between proteins, the beads are usually close enough to each other. When dual-beam optical tweezers and quadrant photodiode detector are used to investigate the interaction of proteins, it is found that the signal of detected beads is greatly affected by adjacent beads. Analysis reveals that the contribution of two beads to the quadrant detector signal is independent. A method for extracting the real interaction signal from a disturbed one is presented. Based on this method, interaction between microtubules and AtMAP65-1 is measured. The results show that this method is useful for measuring short-distance interaction with the precision of piconewton and nanometer scales.
Qu
E
E
Chinese Academy of Sciences, Institute of Physics, Beijing National Laboratory for Condensed Matter Physics, P. O. Box 603, Beijing 100080, China. que@aphy.iphy.ac.cn
Guo
Honglian
H
Xu
Chunhua
C
Liu
Chunxiang
C
Li
Zhaolin
Z
Cheng
Bingying
B
Zhang
Daozhong
D
D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000648:ultrastructure; D001665:Binding Sites; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008846:Micromanipulation / Q000295:instrumentation* / Q000379:methods*; D008869:Microtubule-Associated Proteins / Q000737:chemistry* / Q000648:ultrastructure; D008870:Microtubules / Q000737:chemistry* / Q000648:ultrastructure; D055095:Optics and Photonics / Q000295:instrumentation*; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000295:instrumentation* / Q000379:methods*; D013314:Stress, Mechanical
D029681:Arabidopsis Proteins; C492901:MAP65-1 protein, Arabidopsis; D008869:Microtubule-Associated Proteins