Interaction between Reduced Glutathione and PEO鈭扨PO鈭扨EO Copolymers in Aqueous Solutions: Studied by 1H NMR and Spin鈭扡attice Relaxation

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• 作者：Lianwei Jia ; Chen Guo ; Liangrong Yang ; Junfeng Xiang ; Yalin Tang ; Huizhou Liu
• 刊名：Journal of Physical Chemistry B
• 出版年：2011
• 出版时间：March 17, 2011
• 年：2011
• 卷：115
• 期：10
• 页码：2228-2233
• 全文大小：796K
• 年卷期：v.115,no.10(March 17, 2011)
• ISSN：1520-5207

文摘

In order to investigate the effect of PEO鈭扨PO鈭扨EO copolymers on the glutathione (GSH)/glutathione-S-transferase (GST) detoxification system, interaction between the copolymers and GSH is studied by NMR measurements. Selective rotating-frame nuclear Overhauser effect (ROE) experiment confirms that glutamyl (Glu) 伪-H of GSH has spatial contact with EO methylene protons. Spin鈭抣attice relaxation times of GSH Glu 伪-H show a decrease when PEO鈭扨PO鈭扨EO copolymers are added, and the decrease is greater with copolymers possessing more EO units. Other protons of GSH show little change in the presence of the copolymers. The addition of GSH promotes the dehydration of PEO鈭扨PO鈭扨EO copolymers. This results from the breaking of hydrogen bonds between water and the polymers and the forming of hydrogen bonds between Glu 伪-carboxylate protons and oxygen atoms of EO units. The dissociation constant between GSH and P85 copolymer is determined by spin鈭抣attice relaxation measurements, which shows the binding is of low affinity and the two molecules are in fast dissociation kinetics. This study suggests that GSH transporting or utilizing systems may be affected by treatment of PEO鈭扨PO鈭扨EO copolymers.