insect serpins similar to Drosophila melanogaster Serpin 42Dd
Serpins in insects function within development, wound healing and immunity. Drosophila melanogaster Serpin 42Dd, also called serpin 1 (Spn1), regulates Toll-mediated immune responses, functioning as a repressor of Toll activation upon fungal infection. Insect serpins from house flies, fruit flies, and stable flies are included in this subfamily. SERine Proteinase INhibitors (serpins) exhibit conformational polymorphism shifting from native to cleaved, latent, delta, or polymorphic forms. Many serpins, such as antitrypsin and antichymotrypsin, function as serine protease inhibitors which regulate blood coagulation cascades. Non-inhibitory serpins perform many diverse functions such as chaperoning proteins or transporting hormones. Serpins are of medical interest because mutants have been associated with blood clotting disorders, emphysema, cirrhosis, and dementia. A classification based on evolutionary relatedness has resulted in the assignment of serpins to 16 clades designated A-P along with some orphans.
Comment:depending on the conformational state, the RC loop is surface accessible in the active form or buried and inserted as the central beta strand in the inactive form.
Jiyao W et al.(2023). "The conserved domain database in 2023.",