Cyclic nonapeptide

Oxytocin [50-56-6] M 1007.2, m dec on heating, [a] -26.2"(c 0.53, N AcOH). A cyclic nonapeptide which was purified by countercurrent distribution between solvent and buffer. It is soluble in H2O, rt-BuOH and isoBuOH. [Bodanszky and du Vigneaud J Am Chem Soc 81 2504 1959 Cash et al. J Med Pharm Chem 5 413 1962 Sakakibara et al. Bull Chem Soc Jpn 38 120 1965 solid phase synthesis Bayer and... 

AVP and OT are cyclic nonapeptides with a disulphide bridge between the cysteine residues 1 and 6, resulting in a six-amino acid ring and a COOH-terminal a-amidated three-residue tail. OT differs only in two amino acids from AVP lie in position 3, which is essential for OT recqrtor (OTR) stimulation and Leu in position 8. AVP has a Phe in position 3 and an Arg in position 8. Arg 8 is essential for acting upon vasopressin receptors (Fig. 1). Lysipressin, found in pigs and some marsupials, has a Lys in position 8 [1]. 

Vasopressin, also called antidiuretic hormone (ADH), is a cyclic nonapeptide hormone, which is released from the posterior pituitary. Its primary function in the body is to regulate extracellular fluid volume by affecting renal handling of water. Specific actions include inhibition of... 

Karplus-Bystrov equation). NH Peaks (observable in water or non-aqueous solvents, not in HzO) must be accurately assigned, and this has caused controversy in the cyclic nonapeptides oxytocin [30] and vasopressin [101]. The complete assignment of the NH resonances of the octapeptide angiotensin II (10) in H2O has been accomplished [102] by... 

Posterior pituitary hormones include vasopressin and oxytocin, which are formed as precursor molecules in the paraventricular nucleus of the hypothalamus, and transported down axons to be secreted into the portal capillaries. They are cyclic nonapeptides. Mammalian vasopressin has an Arg residue (arginine vasopressin ... 

Oxytocin and vasopressin are two cyclic nonapeptide hormones produced by the posterior pituitary gland. Oxytocin regulates uterine contraction and lactation and may be administered when it is necessary to induce labor at childbirth. Note that its structure includes two cysteine units Joined by a disulfide bond, and, once again, the C-terminal amino acid is present as the amide. Vasopressin... 

Kemp, D.S. McNamara, P.E. (informationally restricted cyclic nonapeptides derived from L-cysteine and LL-3-amino-2-piperidino-6-carboxylic acid (LL-acp), a potent b-turn-inducing dipeptide analogue. J. Org. Chem. 50, 5834-5838 (1985). 

It has also been described that combining a CPP with a cancer-related peptide yields a chimeric peptide with tumor specificity that can carry cargo molecules inside cells (Mae et al., 2008). For instance, Myrberg et al. (2008) successfully attached the breast tumor cyclic nonapeptide named PEGA (Essler and Ruoslahti, 2002) to the well-studied CPP pVEC (Elmquist et al 2001). These authors demonstrated that the peptide alone does not cross the plasma membrane. However, when conjugated with... 

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