Receptors peptides

The BZ stmcture also has provided a molecular scaffold for a number of peptide receptor ligands (26). Antagonists for the cholecystokinin (CCK-A) receptor, eg, devazepide (65), the thyrotropin-releasing hormone (TRH) receptor, eg, midazolam (66), and the /i -opiate receptor, eg, tifluadom (67), as well as a series of ras famyl transferase inhibitors, eg, BZA-2B (68) (30) have been identified (Table 4). 

In particular, three residues thought to be critical for binding erythropoietin (Phe 93, Met ISO, and Phe 205) are fully buried in the structure of the peptide-receptor complex. (From J.A. Wells, Science 273 449-450, 1996.)... 

Pasternak GW (2001) Incomplete cross tolerance and multiple p opioid peptide receptors. Trend Pharmacol Sci 22 67-70... 

While none of these neutrophil receptors has yet been sequenced, partial purification of the formyl peptide receptors has been reported (16). The formyl peptide receptor is particularly attractive because of the extensive structure-activity studies on peptide ligands by Freer and coworkers (17,18). The receptor is a trans-membrane glycoprotein with apparent molecular weight of 60,000 based on proteolysis (19) and photoaffinity (20) labeling studies. 

Shen W, Li B, Wetzel MA, Rogers TJ, Henderson EE, Su SB, Gong W, Le Y, Sargeant R, Dimitrov DS, Oppenheim JJ, Wang JM (2000) Down-regulation of the chemokine receptor CCR5 by activation of chemotactic formyl peptide receptor in human monocytes. Blood 96 2887-2894... 

Recently, nonpeptide compounds have been developed for many peptide receptor systems. These compounds, which usually are discovered through screening of chemical files, generally do not resemble the corresponding peptide ligands chemically. Nevertheless, they act as specific and... 

The differentiation effect of lycopene was associated with elevated expression of several differentiation-related proteins, such as cell surface antigen (CD14), oxygen burst oxidase and chemotactic peptide receptors (Amir et al., 1999). Recently, it has also been reported that lycopene was also able to stimulate the differentiation marker alkaline phosphatase activity in... 

Ni Q., Xu H., Partilla J. et al. Opioid peptide receptor studies. Interaction of opioid peptides and other drugs with four subtypes of the K2 receptor in guinea pig brain. Peptides. 16 1083, 1995. 

Kieffer BL. Recent advances in molecular recognition and signal transduction of active peptides receptors for opioid peptides. Cell Mol Neurobiol 1995 15 615— 635. 

Reported applications of SASD involve modification of lipopolysaccharide (LPS) molecules and studying their interaction with albumin and an antibody directed against LPS (Wollenweber and Morrison, 1985), identification of the murine interleukin-3 receptor and an N-formyl peptide receptor (Sorenson et al., 1986), crosslinking of factor V and Va to iodinated peptides... 

Koller, D. et al. (2004) Selective inactivation of adrenomedullin over calcitonin gene-related peptide receptor function by the deletion of amino acids 14-20 of the mouse calcitonin-like receptor. J. Biol. Chem. 279, 20387-20391. 

Schmitt, M., Painter, R.G., Jesaitis, A.J., Preissner, K., Sklar, L.A., and Cochrane, C.G. (1983) Photoaffinity labeling of the N-formyl peptide receptor binding site of intact human polymorphonuclear leukocytes./. Biol. Chem. 258, 649-654. 

Most neuropeptide receptors are seven-transmembrane-domain, G-protein-coupled receptors 326 Neuropeptide receptors are not confined to synaptic regions 327 Expressions of peptide receptors and the corresponding peptides are not well matched 327... 

Neuropeptide receptors are not confined to synaptic regions. Peptidergic neurotransmission often operates on a slower time scale than conventional neurotransmitters, so it is not surprising that peptide receptors are often localized at a distance from the synapse. For example, although some substance P terminals contact membranes loaded with substance P receptor, only a small fraction of the substance P receptor-laden membrane is apposed to synaptic terminals. Substance P may diffuse a considerable distance from its release site and still find a receptor with which it can interact [21]. 

Expressions of peptide receptors and the corresponding peptides are not well matched. Neuropeptides can act at... 

Similarly, five closely related melanocortin receptors that respond to various peptides derived from the POMC precursor have been identified (Fig. 18-7) [24]. As expected, the receptor on adrenal cortical cells responds best to ACTH, which normally stimulates adrenal steroidogenesis, and the receptor on melano cytes responds best to aMSH, which causes skin darkening. However, the pattern of melanocortin receptor expression in the brain is not simply explained by the known patterns of peptide expression in the brain or by the known effects of POMC-derived peptides when applied to various brain regions. With this number of peptide receptors, it is obvious that production of final peptide products must be precisely controlled and that different biosynthetic processing pathways can dramatically affect the biological activity observed (Figs 18-5,18-7). 

Control of feeding behavior involves peripheral peptides (insulin, ghrelin, leptin) plus several peptides in the CNS (orexins/hypocretins, CCK, galanin, MSH, neuropeptide Y, CRH, cocaine-and-amphetamine-regulated transcript (CART)) [35, 36]. Some of the same peptides are involved in reward systems crucial to drug addiction. Specific receptor blockers are being tested for many of these peptide-receptor systems, with the hope of very selective actins with minimal side effects [35], For example, there are two CCK receptor subtypes, CCK-A and... 

Helke, C. J., Krause, J. E., Mantyh, P. W., Couture, R. and Bannon, M. J. Diversity in mammalian tachykinin peptidergic neurons multiple peptides, receptors, and regulatory mechanisms. FASEB J 4 1606-1615,1990. 

Reubi, J. C. Peptide receptors as molecular targets for cancer diagnosis and therapy. Endocrinol. Rev. 24 389MZ7,2003. 

Figure 17.1. Neurotransmission (specific case of peptidergic cells). Production of the peptides in the cel I body (1). Packing of the peptides i nto large dense core vesicles for further transport to the axons (2). Release of neuropeptides from the cell soma (3) dendrites (4) and outside of the synapse (5). Release of classic neurotransmitters in the synaptic cleft (6). G-protein-coupled type receptors, which act as peptide receptors. (See color insert.)...

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