利用NMR技术研究极性二肽与金属离子间的相互作用

Study of the Interaction Between Polar Dipeptides and Metal Ions by NMR

利用核磁滴定法研究了极性链状二肽(均为LL构型)与金属离子之间的相互作用.极性二肽在与一价金属离子相互作用时,两者间的化学计量比为1∶1,并求得Li+与10种极性二肽结合常数的大小,其中与L-Glu-L-Glu的结合常数最大,这可能与L-Glu-L-Glu含有较多的富电子原子有关.在此基础上又研究了Cu2+,Zn2+,Co2+3种二价金属离子与极性二肽间的相互作用,结果表明,二价金属离子与二肽间的相互作用是通过两步完成的.

The interactions of 10 polar chain dipeptides（ L-L configuration） with metal ions were examined by NMR. These polar chain dipeptides exhibited a tremendous selectivity toward monovalent mental ion,showing a stoichiometric binding with 1∶ 1,and the association constants of dipeptides with Li＋were acquired. The results showed that L-Glu-L-Glu had stronger binding ability toward Li＋ions than other dipeptides,and suggested the electron-rich atoms in L-Glu-L-Glu molecular were favorable for the interaction with metal ions. Furthermore,the interactions of divalent metal ions（ Cu2 ＋,Zn2 ＋,Co2 ＋） with 10 polar chain dipetieds were studied,which implied the interaction between them was carried out in two stages.