This paper has some interesting results and some elegant experimentation.
However, I would like to propose an alternative interpretation of the results obtained for inhibition of amyloid-β toxicity by catalase.
Zhang et al. have demonstrated that catalase inhibition of amyloid-β toxicity is independent of H2O2 generation, and I identified a binding interaction between catalase and amyloid-β (Milton, 1999).
The key amyloid-β residues for this interaction are 31-35. The substitution of Met 35 for Val in this paper may therefore significantly alter the binding affinity of catalase for amyloid-β and would provide an alternative explanation for the failure of catalase to totally protect against the toxicity of this mutated amyloid-β form.
The catalase amyloid-β binding domain has been identified (Milton et al., 2001) and would provide a ready tool to assess whether the protection required an H2O2 degrading activity or was due to the binding of amyloid-β to catalase.
Zhang Z, Rydel RE, Drzewiecki GJ, Fuson K, Wright S, Wogulis M, Audia JE, May PC,...