C1-inhibitor [SEP] found in taxon
other serpins, which is the part of C1-inhibitor that provides the inhibitory activity. The N-terminal domain (also some times referred to as the "N-terminal tail") is not essential for C1-inhibitor to inhibit proteases. This domain has no similarity to other proteins. C1-inhibitor is highly glycosylated, bearing both N- and O-glycans. N-terminal domain is especially heavily glycosylated.
Genetics.
The human C1-inhibitor gene ("SERPING1") is located on the eleventh chromosome (11q11-q13.1).
Role
isolated from "Streptomyces griseus" in 1983. During a screen seeking to identify microbial secondary metabolites whose activity mimicked that of two cardiac glycosides, bafilomycin C1 was identified as an inhibitor of P-ATPase with a k of 11 μM. Bafilomycin C1 was found to have activity against "Caenorhabditis elegans", ticks, and tapeworms, in addition to stimulating the release of γ-aminobutyruc acid (GABA) from rat synaptosomes. Independently, bafilomycin A1 and other derivatives were isolated from "S. griseus" and shown to have antibiotic activity