The effect of copper chelators on Zn(-) Superoxide Dismutase Lucy Brennan Dr. Joe Beckman Dr. Kari Trumbull

Amyotrophic Lateral Sclerosis  Motor neuron disease characterized by progressive paralysis  10% of cases are familial  Mutations in SOD account for up to 7% of fALS  Motor neuron disease characterized by progressive paralysis  10% of cases are familial  Mutations in SOD account for up to 7% of fALS

Superoxide dismutase  (Cu 2+ Zn)SOD+O > (Cu 1+ Zn)SOD+O 2 (Cu 1+ Zn)SOD +O H + --> (Cu 2+ Zn)SOD+H 2 O 2  Mutations linked to structural instability  Zn(-)SOD has a toxic gain of function believed to underlie fALS  (Cu 1+ )SOD +O 2 --> (Cu 2+ )SOD  (Cu 2+ Zn)SOD+O > (Cu 1+ Zn)SOD+O 2 (Cu 1+ Zn)SOD +O H + --> (Cu 2+ Zn)SOD+H 2 O 2  Mutations linked to structural instability  Zn(-)SOD has a toxic gain of function believed to underlie fALS  (Cu 1+ )SOD +O 2 --> (Cu 2+ )SOD

Copper chelators  Dimercaptrol (BAL)  treatment for heavy metal toxicity and Wilson’s disease  Sulfhydral complex  Dimercaptrol (BAL)  treatment for heavy metal toxicity and Wilson’s disease  Sulfhydral complex

Goals  Validation of WST assay  To find a Cu-chelator that effectively removes copper from SOD  Modifying the Cu-chelator into a potential drug for ALS

WST assay

Superoxide detection  An assay including potassium superoxide and WST-1 was performed  Addition of KO 2 - was added to the assay  WST has been reduced

Xanthine assay  WST-1 + Xanthine and Xanthine oxidase  An increased absorbance was noted, indicating that WST-1 is reacting with superoxide

Addition of BAL with Zn(-)SOD

Implications  Validation of WST assay  Limitations  Insight into activity of Zn(-)SOD  Possible chelation therapy for ALS  Viable test for such compounds

Acknowledgements  HHMI  Kevin Ahern  Dr. Joe Beckman  Dr. Kari Trumbull  HHMI  Kevin Ahern  Dr. Joe Beckman  Dr. Kari Trumbull