Anticalin

Anticalin proteins are being used in lieu of monoclonal antibodies, but are about eight times smaller with a size of about 180 amino acids and a mass of about 20 kDa.

[citation needed] Anticalin proteins have better tissue penetration than antibodies and are stable at temperatures up to 70 °C.

[citation needed] They were mainly developed at the Technical University of Munich and are currently used as research tools.

[5] Characteristic for Anticalin proteins is their barrel structure formed by eight antiparallel β-strands pairwise connected by loops and an attached α-helix.

Conformational deviations are primarily located in the four loops reaching in the ligand binding site.