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Insulin regulated aminopeptidase (IRAP) is a protein that in humans is encoded by the leucyl and cystinyl aminopeptidase (LNPEP) gene. IRAP is a type II transmembrane protein which belongs to the oxytocinase subfamily of M1 aminopeptidases, alongside ERAP1 and ERAP2. It is also known as oxytocinase, leucyl and cystinyl aminopeptidase, placental leucine aminopeptidase (P-LAP), cystinyl aminopeptidase (CAP), and vasopressinase. IRAP is expressed in different cell types, mainly located in specialized regulated endosomes that can be recruited to the cell surface upon cell type-specific receptor activation.
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Tynorphin is a synthetic opioid peptide which is a potent and competitive inhibitor of the enkephalinase class of enzymes which break down the endogenous enkephalin peptides. It specifically inactivates dipeptidyl aminopeptidase III (DPP3) with very high efficacy, but also inhibits neutral endopeptidase (NEP), aminopeptidase N (APN), and angiotensin-converting enzyme (ACE) to a lesser extent. It has a pentapeptide structure with the amino acid sequence Val-Val-Tyr-Pro-Trp (VVYPW).
Amastatin, also known as 3-amino-2-hydroxy-5-methylhexanoyl-L-valyl-L-valyl-L-aspartic acid, is a naturally occurring, competitive and reversible aminopeptidase inhibitor that was isolated from Streptomyces sp. ME 98-M3. It specifically inhibits leucyl aminopeptidase, alanyl aminopeptidase, bacterial leucyl aminopeptidase, leucyl/cystinyl aminopeptidase (oxytocinase/vasopressinase), and, to a lesser extent, glutamyl aminopeptidase, as well as other aminopeptidases. It does not inhibit arginyl aminopeptidase. Amastatin has been found to potentiate the central nervous system effects of oxytocin and vasopressin in vivo. It also inhibits the degradation of met-enkephalin, dynorphin A, and other endogenous peptides.
Hormones during pregnancy are the result of an intricate interaction between hormones generated by different glands and organs. The primary hormones involved comprise human chorionic gonadotropin (hCG), progesterone, estrogen, human placental lactogen (hPL), and oxytocin. Hormones are synthesized in certain organs, including the ovaries, placenta, and pituitary gland. These hormones have essential functions in pregnancy test, maintaining the uterine lining, fetal development, preventing premature labor, and the initiation and support of labor.
References
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- ↑ Klimek, Marek (August 2005). "Comparative analysis of ACTH and oxytocinase plasma concentration during pregnancy". Neuro Endocrinology Letters. 26 (4): 337–341. ISSN 0172-780X. PMID 16136013.
- ↑ Meisenberg G, Simmons WH (1984). "Amastatin potentiates the behavioral effects of vasopressin and oxytocin in mice". Peptides. 5 (3): 535–9. doi:10.1016/0196-9781(84)90083-4. PMID 6540873. S2CID 3881661.
- ↑ Stancampiano R, Melis MR, Argiolas A (1991). "Proteolytic conversion of oxytocin by brain synaptic membranes: role of aminopeptidases and endopeptidases". Peptides. 12 (5): 1119–25. doi:10.1016/0196-9781(91)90068-z. PMID 1800950. S2CID 36706540.
- ↑ Itoh C, Watanabe M, Nagamatsu A, Soeda S, Kawarabayashi T, Shimeno H (1997). "Two molecular species of oxytocinase (L-cystine aminopeptidase) in human placenta: purification and characterization". Biol. Pharm. Bull. 20 (1): 20–4. doi: 10.1248/bpb.20.20 . PMID 9013800.