Author

David Achila

Date of Award

12-2005

Degree Name

Master of Science

Department

Chemistry

First Advisor

Dr. David L. Huffman

Second Advisor

Dr. David Reinhold

Third Advisor

Dr. Subra Muralidharan

Access Setting

Masters Thesis-Open Access

Abstract

Wilsons disease is an autosomal recessive disorder of copper metabolism which results from mutations in the gene encoding for Wilson disease protein (WDP). The cytosolic N-terminus of WDP comprises six metal binding domains each containing a conserved metal binding motif, GMXCXXC. The contribution of these metal binding domains to copper homeostasis is poorly understood. We have cloned, expressed and purified residues 485 to 633 corresponding to N-terminal metal-binding domains 5 and 6 of WDP (WD5-6). Two of the 3 disease causing mutations in the N-terminal metal binding domains of WDP occur one in each of these domains and the two domains have been shown to be essential for copper induced response, catalytic phosphorylation and other functions of WDP.

We found that WD5-6 binds 2 equivalents of copper, has a pl of 4.97 and behaves as a monomer in solution. We also showed by NMR titration that WD5-6 accepts copper from the fourth metal binding domain of WDP, Cu(l)WD4, and not from Cu(l)Atoxl , the copper chaperone that delivers copper to WDP. Solution NMR structure of apo-WD5-6 was elucidated and found to consist of 2 ferrodoxin-like folds that behaves as a unit in solution.

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Chemistry Commons

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