Peptide insulin

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... 

Excellent performance for the elution of another peptide, insulin (molecular weight 5800 g/mol), was also observed using silica-based monoliths. The efficiency of the monolithic column was much better than that of a column packed with beads, and did not change much even at high flow rates. 

TVpes of preparations (B). As a peptide, insulin is unsuitable for oral administration (destruction by gastrointestinal proteases) and thus needs to be given parenterally. Usually, insulin preparations are injected subcutaneously. The duration of action depends on the rate of absorption from the injection site. 

The names and structures of the twenty natural amino acids are given in Table 1.13. The International Union of Pure and Applied Chemistry (IUPAC) uses the three-letter abbreviations shown in the second column of Table 1.13 to describe amino acids. These are widely used in biological circles as well but are inappropriate when long peptide or protein sequences need to be described. For example, when proinsulin is cleaved, it forms the biologically important peptide insulin and another peptide usually called C-peptide. The human peptide consists of a linear chain of 31 amino acids that have the sequence, from amino to carboxyl, H2N-Glu-Ala-Glu-Asp-Leu-Gln-Val-Glu-Gln-Glu-Leu-Gly-Gly-Gly-Pro-Gly-Ala-Gly-Ser-Leu-Gln-Pro-Leu-Ala-Leu-Glu-Gly-Ser-Leu-Gln-OH. This is readily comprehensible to most chemists because the abbreviations are typically the first three letters of the amino acid. Thus, alanine is Ala and arginine is Arg. Aspartic acid and asparagine cannot both be named Asp so the latter is distinguished as Asn. 

Plasma C-peptide. Insulin secretion in insulin-treated diabetics cannot be assessed by the measurement of plasma insulin since the insulin given therapeutically will also be measured in the assay. However, insulin and its associated connecting-peptide (or C-peptide) are secreted by the islet cells in equimolar amounts (Fig. 2)... 

A. Physiology Insulin is synthesized as a prohormone, proinsulin, an 86-amino-acid singlechain polypeptide. Cleavage of proinsulin and cross-linking result in the two-chain 51-peptide insulin molecule and a 31-amino-acid residual C-peptide. Neither proinsulin nor C-peptide appear to have any physiologic actions. 

Inbibin (activin), beta A Inhibin (activin), beta B Inbibin (activin), beta C Inhibin (activin), beta E Inhibin, alpha Insulin C-peptide Insulin, A chain Insulin, B chain Insulin-like growth factor lA Insulin-like growth factor II Inter-alpha trypsin inhibitor, HI Inter-alpha trypsin inhibitor, H2 Inter-alpha trypsin inhibitor, H4 Inter-alpha trypsin inhibitor, L Interferon alpha Interferon beta Interferon gamma Interleukin-1 beta Interleukin-10 Interleukin-12, alpha Interleukin-12, beta Interleukin-1 receptor antagonist Interleukin-2 Interleukin-4... 

Unit Peptides Phage fd B protein 51-Unit Peptides Insulin Arg-insulin... 

The separation of three peptides insulin chains A and B and j3-endorphin fragments 1-27 was achieved under physiological conditions by a temperature change (Kanazawa and Okano, 2011). TTie temperature rise increases hydrophobicity of temperature-responsive carriers and hence the retention time of the peptides provides better separation (Fig. 13.3). As peptides have... 

Chromatography of mixture of the peptides insulin chain A (1), insulin chain B (3) and jS-endorphin fragments 1-27 (2) from pNIPAM-BMA-modified column (BMA 5%, eluent 0.9% NaCI aqueous solution). (Source Reproduced from Kanazawa and Okano (2011).Temperature-responsive chromatography for the separation of biomolecules. Journal of Chromatography A, 1218, 8738-8747. Copyright (2011), with permission from Elsevier.) (Kanazawa and Okano, 2011). 

Systemic diseases Proteins and peptides Insulin Growth hormone Leuprolide acetate... 

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