Kinetic assay of the Michael addition-like thiol-ene reaction and insight into protein bioconjugation.
The chemical modification of proteins is a valuable technique in understanding the functions, interactions, and dynamics of proteins. Reactivity and selectivity are key issues in current chemical modification of proteins. The Michael addition-like thiol-ene reaction is a useful tool that can be used to tag proteins with high selectivity for the solvent-exposed thiol groups of proteins. To obtain insight into the bioconjugation of proteins with this method, a kinetic analysis was performed. New vinyl-substituted pyridine derivatives were designed and synthesized. The reactivity of these vinyl tags with L-cysteine was evaluated by UV absorption and high-resolution NMR spectroscopy. The results show that protonation of pyridine plays a key role in the overall reaction rates. The kinetic parameters were assessed in protein modification. The different reactivities of these vinyl tags with solvent-exposed cysteine is valuable information in the selective labeling of proteins with multiple functional groups.
State Key Laboratory of Elemento-organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Weijin Road 94, Tianjin 300071 (China), Fax: (+86) 22-23500623.
Fei-He
FH
Ma
Jia-Liang
JL
Chen
Qing-Feng
QF
Li
Hui-Hui
HH
Zuo
Feng
F
Huang
Xun-Cheng
XC
Su
D060326:Chemistry Techniques, Synthetic; D003545:Cysteine / Q000737:chemistry; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015335:Molecular Probes / Q000138:chemical synthesis / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry; D014753:Vinyl Compounds / Q000737:chemistry
D015335:Molecular Probes; D011506:Proteins; D011725:Pyridines; D014753:Vinyl Compounds; D003545:Cysteine
NMR spectroscopy; conjugation; proteins; thiol chemistry; thiol-ene reaction