The effect of copper chelators on Zn(-) Superoxide DismutaseThe effect of copper chelators on Zn(-) Superoxide Dismutase

Lucy Brennan

Dr. Joe Beckman

Dr. Kari Trumbull

Lucy Brennan

Dr. Joe Beckman

Dr. Kari Trumbull

Amyotrophic Lateral SclerosisAmyotrophic 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 dismutaseSuperoxide dismutase

(Cu2+ Zn)SOD+O2---> (Cu1+ Zn)SOD+O2

(Cu1+ Zn)SOD +O2-+2H+--> (Cu2+ Zn)SOD+H2O2

Mutations linked to structural instability Zn(-)SOD has a toxic gain of function believed to

underlie fALS (Cu1+)SOD +O2--> (Cu2+)SOD+ 02

-

(Cu2+ Zn)SOD+O2---> (Cu1+ Zn)SOD+O2

(Cu1+ Zn)SOD +O2-+2H+--> (Cu2+ Zn)SOD+H2O2

Mutations linked to structural instability Zn(-)SOD has a toxic gain of function believed to

underlie fALS (Cu1+)SOD +O2--> (Cu2+)SOD+ 02

-

Copper chelatorsCopper 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

GoalsGoals

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

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 assayWST assay

Superoxide detectionSuperoxide detection

An assay including potassium superoxide and WST-1 was performed

Addition of KO2- was

added to the assay WST has been

reduced

An assay including potassium superoxide and WST-1 was performed

Addition of KO2- was

added to the assay WST has been

reduced

Xanthine assayXanthine assay

WST-1 + Xanthine and Xanthine oxidase An increased

absorbance was noted, indicating that WST-1 is reacting with superoxide

WST-1 + Xanthine and Xanthine oxidase An increased

absorbance was noted, indicating that WST-1 is reacting with superoxide

Addition of BAL with Zn(-)SODAddition of BAL with Zn(-)SOD

ImplicationsImplications

Validation of WST assay Limitations

Insight into activity of Zn(-)SOD Possible chelation therapy for ALS

Viable test for such compounds

Validation of WST assay Limitations

Insight into activity of Zn(-)SOD Possible chelation therapy for ALS

Viable test for such compounds

AcknowledgementsAcknowledgements

HHMI Kevin Ahern Dr. Joe Beckman Dr. Kari Trumbull

HHMI Kevin Ahern Dr. Joe Beckman Dr. Kari Trumbull