Amyotrophic lateral sclerosis (ALS) is an untreatable disease, which affects the upper and lower motor neurons in the brain and spinal cord. The first symptoms include motor impairments, loss of coordination, dysarthria and dysphagia, with respiratory failure occuring only at later stages. The development of familial and sporadic ALS is often associated with misfolding of RNA-binding proteins and the formation of aggregates. The first gene discovered in connection to ALS was superoxide dismutase 1 (SOD1), which converts superoxide into oxygen and hydrogen peroxide and accounts for 20 % of familial ALS (fALS) and 1 % of sporadic ALS (sALS) cases. Another important gene discovered later is C9orf72, which mantains membrane dynamics and participates in autophagy. Mutations in this gene cause 45 % of fALS and 7 % sALS and can also lead to frontotemporal dementia. There were more genes discovered, associated with the ALS, for example FUS and TARDBP. Aminoacyl-tRNA synthetases (aaRS) are enzymes that catalyze the acylation of a tRNA molecule with its corresponding amino acid. Increasing correlations between aaRSs and ALS have been observed, as they participate in protein translation and interact with SOD1, TARDBP, FUS and others. Our purpose was to prepare different recombinant single-chain variable fragments(scFv) for detecting aaRSs, that are involved in ALS, with which we would perform the imunodetection of proteins connected to disease mechanism research studies. In this thesis project we isolated scFv against aminoacyl-tRNA synthetases MARS and DARS and also against protein MATR3. We used an E.coli BL21 [DE3] expression system and isolated the proteins from the periplasm with nickel immobilized metal affinity chromatography. We isolated 4,9 mg of O-DARS-1 scFv with A260/A280 ratio 0,91, for which we also successfully performed the imunodetection after western blot.
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