標題: Deciphering the Catalysis-Associated Conformational Changes of Human Adenylate Kinase 1 with Single-Molecule Spectroscopy
作者: Lin, Chien Y.
Huang, Jung Y.
Lo, Leu-Wei
光電工程學系
Department of Photonics
公開日期: 14-十一月-2013
摘要: Human adenylate kinase isoenzyme 1 (AK1) is the key enzyme in maintaining the cellular energy homeostasis. The catalysis-associated conformational changes of AK1 involve large-amplitude rearrangements. To decipher the conformational changes of AK1 at the single-molecule level, we tagged AK1 with two identical fluorophores, one near the substrate-binding site and the other at the boundary of the core domain. We found that magnesium ion binding to AK1 increases the structural heterogeneity of AK1, whereas ADP binding reduces the structural heterogeneity. We exploited the hidden Markov model to extract the underlying catalysis-associated conformational dynamics and determined thermodynamic parameters of the multiple catalytic pathways. The third-order correlation difference calculated from photon fluctuation traces reveals the irreversible nature of the conformational motions, suggesting that single-molecule AK1 is in a nonequilibrium steady state. This discovery offers a fresh viewpoint to look into the molecular mechanisms of cellular biochemistry.
URI: http://dx.doi.org/10.1021/jp4019537
http://hdl.handle.net/11536/23264
ISSN: 1520-6106
DOI: 10.1021/jp4019537
期刊: JOURNAL OF PHYSICAL CHEMISTRY B
Volume: 117
Issue: 45
起始頁: 13947
結束頁: 13955
顯示於類別:期刊論文


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  1. 000327111200001.pdf