Alicia Douglas

Document Type

Honors Project

First Advisor

Dr. Ellen Mitchell

Degree Award Date

Spring 2002


Sequence Selectivity, Cadmium Binding, DNA




The sequence selectivity of cadmium binding to deoxyribonucleic acid (DNA) was investigated with the use of 1H NMR and 111Cd NMR. spectroscopy. Metal ion titrations of three DNA dodecamers, two thioguanine hexamers, a DNA decamer and a DNA 18-mer were carried out. All the sequences investigated contained a three-purine run excluding a thioguanine 6-mer and the DNA decamer. The 1H NMR experiments showed downfield shifting indicating conformational changes caused by metal binding. The 111 Cd NMR experiments for the three DNA dodecamers and DNA 18-mer all indicated cadmium binding. From previous research it is believed that cadmium binds readily to three-purine runs with a coordination sphere involving the N7 of guanine and five water molecules. The data obtained for the sequences supports this coordination sphere.