Antibody fragment degrading and removing abnormal TDP-43

A modified antibody fragment that binds to misfolded TAR DNA-binding protein of 43 kDa, wherein the modified antibody fragment comprises an antibody fragment and a chaperone-mediated autophagy localizing signal peptide comprising KFREQ (SEQ ID NO:

• 8) and linked to the C-terminus of the antibody fragment;
• the antibody fragment comprising:
• a heavy-chain variable region comprising a heavy-chain CDR 1 consisting of an amino acid sequence GFNIKDYY (SEQ ID NO:
• 1), a heavy-chain CDR 2 consisting of an amino acid sequence IDPEDGET (SEQ ID NO:
• 2), and a heavy-chain CDR 3 consisting of an amino acid sequence TIIYYYGSRYVDY (SEQ ID NO:
• 3);
• and
• a light-chain variable region comprising a light-chain CDR 1 consisting of an amino acid sequence SSISSSY (SEQ ID NO:
• 4), a light-chain CDR 2 consisting of an amino acid sequence RTS, and a light-chain CDR 3 consisting of an amino acid sequence QQGSSIPLT (SEQ ID NO:
• 5);
• and
• wherein the antibody fragment is a scFv;
• and
• wherein the antibody fragment and the chaperone-mediated autophagy localizing signal peptide are directly bonded, or an amino acid sequence exists between them.