The present invention provides an isolated protein exhibiting an antiaggregating activity and/or disaggregating activity toward a target protein comprising an extended polyQ stretch. The protein comprises a Zn.sup.2+-binding region, wherein the conserved motif is HxxEHx.sub.75-80E and x is any amino acid. The nucleic acid construct encoding said protein as well as the corresponding mRNA sequence are also provided. The protein, the nucleic acid construct or mRNA sequence are for use in a method for prevention or treatment of a neurodegenerative disease that is caused by aggregates comprising at least one target protein and/or by the mRNA encoding for said target protein, wherein the target protein causes e.g. Huntington's disease or Machado-Joseph disease.