Abstract
Objective: To provide a kinetic model(s) and reveal the mechanism of thymoquinone and Poloxin blocking an emerging anti-cancer target, human Polo-like kinase 1 (hPlk1) Polo-box domain (PBD). Methods: The binding kinetics was determined by using a fluorescence polarization based assay. The putative mechanism was examined with a competition test. Results: Thymoquinone follows a one-step binding with an association rate constant (k1) of 6.635×103 L·mol-1·min-1. Poloxin fit a two-step binding with a dissociation constant (Ki) of 118 μmol/L for the intermediate complex and its isomerization rate (k4) of 0.131 5 min-1 to form an irreversible adduct. No significant dissociation was observed for either ligand up to 13 h. The inhibitors responded insignificantly to the presence of Michael donors as hPlk1-PBD competitors. Conclusion: Thymoquinone and Poloxin are slow-tight ligands to the hPlk1-PBD with kinetic models distinct from each other. Michael addition as the mechanism is excluded.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 136-142 |
| Number of pages | 7 |
| Journal | Journal of Medical Colleges of PLA |
| Volume | 25 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jun 2010 |
| Externally published | Yes |
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Keywords
- Fluorescence polarization
- Irreversible inhibitor
- Kinetics
- Polo-like kinase
ASJC Scopus subject areas
- Medicine(all)
Cite this
Thymoquinone and Poloxin are slow-irreversible inhibitors to human Polo-like kinase 1 Polo-box domain. / Zhou, Yin; Jianhua, Chen; Rehse, Peter H.
In: Journal of Medical Colleges of PLA, Vol. 25, No. 3, 06.2010, p. 136-142.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Thymoquinone and Poloxin are slow-irreversible inhibitors to human Polo-like kinase 1 Polo-box domain
AU - Zhou, Yin
AU - Jianhua, Chen
AU - Rehse, Peter H.
PY - 2010/6
Y1 - 2010/6
N2 - Objective: To provide a kinetic model(s) and reveal the mechanism of thymoquinone and Poloxin blocking an emerging anti-cancer target, human Polo-like kinase 1 (hPlk1) Polo-box domain (PBD). Methods: The binding kinetics was determined by using a fluorescence polarization based assay. The putative mechanism was examined with a competition test. Results: Thymoquinone follows a one-step binding with an association rate constant (k1) of 6.635×103 L·mol-1·min-1. Poloxin fit a two-step binding with a dissociation constant (Ki) of 118 μmol/L for the intermediate complex and its isomerization rate (k4) of 0.131 5 min-1 to form an irreversible adduct. No significant dissociation was observed for either ligand up to 13 h. The inhibitors responded insignificantly to the presence of Michael donors as hPlk1-PBD competitors. Conclusion: Thymoquinone and Poloxin are slow-tight ligands to the hPlk1-PBD with kinetic models distinct from each other. Michael addition as the mechanism is excluded.
AB - Objective: To provide a kinetic model(s) and reveal the mechanism of thymoquinone and Poloxin blocking an emerging anti-cancer target, human Polo-like kinase 1 (hPlk1) Polo-box domain (PBD). Methods: The binding kinetics was determined by using a fluorescence polarization based assay. The putative mechanism was examined with a competition test. Results: Thymoquinone follows a one-step binding with an association rate constant (k1) of 6.635×103 L·mol-1·min-1. Poloxin fit a two-step binding with a dissociation constant (Ki) of 118 μmol/L for the intermediate complex and its isomerization rate (k4) of 0.131 5 min-1 to form an irreversible adduct. No significant dissociation was observed for either ligand up to 13 h. The inhibitors responded insignificantly to the presence of Michael donors as hPlk1-PBD competitors. Conclusion: Thymoquinone and Poloxin are slow-tight ligands to the hPlk1-PBD with kinetic models distinct from each other. Michael addition as the mechanism is excluded.
KW - Fluorescence polarization
KW - Irreversible inhibitor
KW - Kinetics
KW - Polo-like kinase
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U2 - 10.1016/S1000-1948(10)60032-9
DO - 10.1016/S1000-1948(10)60032-9
M3 - Article
VL - 25
SP - 136
EP - 142
JO - Journal of Medical Colleges of PLA
JF - Journal of Medical Colleges of PLA
SN - 1000-1948
IS - 3
ER -