Insulin chemical structure

Fig. 17 (a) Chemical structure of polythiophene poly((3,3"-di[(S)-5-amino-5-carbonyl-3-oxapen-tyl]-[2,2 5 2"])-5-,5"-terthiophenylene hydrochloride), PONT, (b) Emission spectra of 6.5 pM PONT—HC1 (on a chain basis) in 25 mM HC1 (black spectrum), 25 mM HC1 with 5.0 pM of native bovine insulin (blue spectrum), 25 mM HC1 with 5.0 pM fibrillar bovine insulin (red spectrum). The emission spectra were recorded with excitation at 400 nm [31]... 

Therapeutic Function Hypoglycemic Chemical Name See structure Common Name Isophane insulin injection Structural Formula Isophane insulin Chemical Abstracts Registry No. 53027-39-7... 

In the selected example by Lam et al. [101] many peptide libraries were prepared using the mix and split technique and tested in different on-bead screens. Incomplete libraries were tested (the population of most of them was more than a million compounds), and the positive structures were exploited through focused libraries. Some libraries were screened against an anti-insulin monoclonal antibody tagged with alkaline phosphatase, which allowed an enzyme-linked colorimetric detection. Only the beads bound to the murine MAb showed a tourquoise color, while the vast majority remained colorless (details of the technical realization of the assay can be found elsewhere [101, 102]). The chemical structure linked to the positive beads was then easily determined via Edman degradation of the peptide sequences. 

RIA is one of the primary techniques which has historically been important for clinical knowledge and testing for hormones. Indeed, RIA was first developed by Yalow and Berson to measure the circulating levels of the important hormone insulin. However, since this early description of the technique, very many similar assays have appeared for hundreds of substances differing markedly in chemical structure and biological activity. 

Since Berson and Yalow first described the radioimmunoassay for insulin, similar assays have appeared in the literature for several hundred substances that differ markedly in chemical structure and biological activity. These represent only a small fraction of the biologically important molecules that could be analyzed by this technique. This overview is intended primarily for the investigator who wishes to develop a new radioimmunoassay for a specific substance. It directs his attention to papers that provide background information and necessary procedural details. 

Insulin. As mentioned previously, insulin is one of the few biologically interesting compounds for which a full chemical structure is known. By using this knowledge, which is not available in other cases, Lindley and Rollett (1237) could build a more exact model which included H bonds in the side chains and which changed from right- to left-handed spirals in the main chains. 

Ca2+ Fluxes. As can be expected, sulphonylureas increase net Ca2+ uptake along voltage-dependent Ca2+ channels (Henquin, 1980b Ammon et al., 1986) and, as far as the chemical structure is concerned, only those sulphonylureas that produce insulin release enhance uptake of Ca2+ (Heilman, 1981). Uptake of Ca2+ is associated with increased [Ca2+]j (Abrahamson et al., 1985). In HIT cells, membrane depolarization effected by the addition of glibenclamide or tolbutamide increased intracellular Ca2+ by activating voltage-dependent Ca2+ channels (Nelson et al., 1987). 

Fig. 3. Chemical structure of the insulin agonist mimetic developed by Merck s scientists (Adapted from Zhang et al., 1999).

Fig. 4.2-12 Use of the reverse dimerization system to control protein secretion in mammalian cells, (a) Scheme for inducible secretion, (b) Chemical structure of monomeric ligand AP21998. (c) Pulsatile release of insulin from engineered cells. 

Insulin, Inutral Optisulin long. Polypeptide hormone produced in the beta cells of the islets of Laager-bans situated in the pancreas of all vertebrates. Synthesized in vivo via a single chain polypeptide precursor, proinsulin, native conformation has been established. Secreted directly into the bloodstream where it regulates carbohydrate metabolism, influences the synthesis of protein and of RNA, and the formation and storage of neutral lipids. The first protein for which chemical structure and precise mol wt were determined Sanger, Tuppy, Biochem. J. 49, 463, 481 (1951) ... 

The synthetic oral hypoglycemic agents have been added to the therapeutie armamentarium over the last five decades in lieu of the various insulin variants discussed earlier. In this partieular section the focus shall be made on the different categories of synthetic oral hypoglycemic agents based on their chemical structures, namely ... 

Hormones are transported from the sites of their synthesis to the sites of action by the bloodstream (Figure 24.5). In terms of their chemical structure, some typical hormones are steroids, such as estrogens, androgens, and mineralocorticoids (Section 21.8) polypeptides, such as insulin and endorphins (Section 3.5) and amino acid derivatives, such as epinephrine and norepinephrine (Table 24.3). 

Fig. 3 Chemical structure of TMC-Cys and schematic representation of formation of self-assembled TMC-Cys/insulin nanoparticles (TMC-Cys NP) [37]...

Peptide hormones are produced by the endocrine glands (pituitary, thyroid, pineal, adrenal, and pancreas) or by various organs such as the kidney, stomach, intestine, placenta, or liver (Table 3.4). Peptide hormones can have complex, convoluted structures with hundreds of amino acids. Figure 3.2 illustrates the chemical structure of human insulin and its three-dimensional shape. Insulin is made of two amino acid sequences. The A-Chain has 21-amino acids, and the B-Chain has 30-amino acids. The chains are linked together through the sulfur atoms of cysteine (Cys). Peptide hormones are generally different for every species, but they may have similarities [11]. Human insulin is identical to pig insulin, except that the last amino acid of the B-Chain for the pig is alanine (Ala) instead of threonine (Thr) (lUPAC and lUBMB) [9] and [11]. 

FIGURE 8.21 Chemical structure of the copoly(ester amide) based on L-lysine and L-leucine amino adds that has been developed to prepare microspheres for oral insulin delivery. 

FIGURE 13.20 Polythiophene-based probes for amyloid and protein aggregate detection (a) chemical structures of polythiophene derivatives PONT (b) emission spectra of PTAA in free solution (c) emission spectra of PTAA solution complexed with native insulin or amyloid insulin, and (d) kinetics of insulin fibrillation. Reprinted with permission from [190]. Copyright 2005 American Chemical Society. 

It is not quite clear how growth hormone exerts its effect at the cellular level. One hypothesis proposes that the major function of the hormone is to stimulate protein synthesis and that this is achieved by the release of insulin-like substances namely, somatomedin A and B. These substances are found in plasma, but their chemical structure is still unknown. Two somato-medins have been found in plasma a large (mol wt 44,000) and a small one (mol wt 22,000). Although there is no evidence of conversion of the large into the small somatomedin, it has been proposed that the high is a precursor of the low molecular weight component [166]. 

Figure 1. Chemical structures of the main families of insulin-enhancmg vanadium(IV) compounds.

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