serpin family A member 14, uterine milk protein and uteroferrin-associated basic protein 2
The uteroferrin(Uf)-associated basic proteins-2(UABP-2/UABP/UfAP) are a group of three (Mr = 42K, 48K, and 50K) antigenically related, basic glycoproteins secreted by the porcine uterus under the influence of progesterone (P4), which exist as heterodimers (Mr = 80,000) with the iron-binding acid phosphatase, Uf. This group also contains UTMP (uterine milk protein), encoded by SERPINA14. UTMP binds noncovalently to the iron-containing glycoprotein uteroferrin, which displays phosphatase activity and is thought to be involved with iron transport to the fetus. Synthesis of these serpins is induced by progesterone in the uterus. UTMP is also an activin-binding protein and has been implicated in regulation of uterine immune function. In general, 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.
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