Evolution strikes again
"One of the most uncommon hinges of vertebrate Ig is that exclusively found in Antarctic fishes: IgM H chain has a remarkably long hinge region, ranging from 14 to 22 amino acid residues, highly polymorphic, and rich in prolines and glycines (Coscia et al, 2000; Coscia et al, 2011; Coscia et al, 2012). Given these peculiar features, the hinge region has been suggested to provide the cold Ig molecule with higher flexibility to exert its function at very low kinetic energy in the Antarctic environment."
#Preprint #Immunology
https://www.biorxiv.org/content/10.1101/2023.10.04.560855v1.full.pdf