Misfolding of Cu/Zn-superoxide dismutase (SOD1) is emerging as a mechanism underlying motor neuron degeneration in individuals with amyotrophic lateral sclerosis (ALS) who carry a mutant SOD1 gene (SOD1 ALS). Here we describe a structure-guided approach to developing an antibody that specifically recognizes monomer-misfolded forms of SOD1. We raised this antibody to an epitope that is normally buried in the SOD1 native homodimer interface. The SOD1 exposed dimer interface (SEDI) antibody recognizes only those SOD1 conformations in which the native dimer is disrupted or misfolded and thereby exposes the hydrophobic dimer interface. Using the SEDI antibody, we established the presence of monomer-misfolded SOD1 in three ALS mouse models, with G37R, G85R and G93A SOD1 mutations, and in a human individual with an A4V SOD1 mutation. Despite ubiquitous expression, misfolded SOD1 was found primarily within degenerating motor neurons. Misfolded SOD1 appeared before the onset of symptoms and decreased at the end stage of the disease, concomitant with motor neuron loss.

SummaryProline-specific dipeptidyl peptidase-like (DPP IV; EC 3.4.14.5)

No abstract

Synthesis of the tripeptide Z-Phe-Arg-SerNH 2 has been accomplished by a recombinant cysteine protease, cathepsin L1 from liver fluke (Fasciola hepatica), using Z-Phe-Arg-OMe as acyl acceptor and SerNH 2 as nucleophile in 0.1 M ammonium acetate pH 9.0-12.5% v/v acetonitrile at 37 o C. LC-MS detection indicated tripeptide formation after 10 min, continuing up to 5.5 h. The ester Z-Phe-Arg-OMe was detected throughout the experiment but the hydrolysis product Z-Phe-Arg-OH appeared early and in quite large amounts. We believe that this is the first application of a parasite protease in enzymatic peptide synthesis.Keywords: Fasciola hepatica cathepsin L1, recombinant, enzymatic peptide synthesis, cysteine proteinase 2 Abbreviations: LC-MS, liquid chromatography-mass spectrometry; m/z, mass-to-charge ratio; rFheCL1, recombinant Fasciola hepatica cathepsin L1; Z, benzoyloxycarbonyl.