Glucagon hormone

The situation is different for other examples—for example, the peptide hormone glucagon and a small peptide, metallothionein, which binds seven cadmium or zinc atoms. Here large discrepancies were found between the structures determined by x-ray diffraction and NMR methods. The differences in the case of glucagon can be attributed to genuine conformational variability under different experimental conditions, whereas the disagreement in the metallothionein case was later shown to be due to an incorrectly determined x-ray structure. A re-examination of the x-ray data of metallothionein gave a structure very similar to that determined by NMR. 

Chorionic gonadotropin, human Corticotropin-releasing hormone Follicle-stimulating hormone Glucagon Lipotropin... 

Glucagon. Also a peptide hormone, glucagon is produced by a-cells of the islets of Langerhans. The overall effects of glucagon include ... 

Table 11.1 Some metabolic effects of insulin. These effects are generally countered by other hormones (glucagon and, in some cases, adrenaline). Hence, the overall effect noted often reflects the relative rates of these hormones present in the plasma...

Gordienko D V, Bolton TB, Cannell MB 1998 Variability in spontaneous subcellular Ca2+ release in guinea-pig ileum smooth muscle cells. J Physiol 507 707-720 Ho R, Shao Z 1991 Axial resolution of confocal microscopes revisited. Optiik 88 147—154 Holz GG, Leech CA, Heller RS, Castonguay N, Habener JF 1999 cAMP-dependent mobilization of intracellular Ca2+ stores by activation of ryanodine receptors in pancreatic [j cells. A Ca2+ signaling system stimulated by the insulinotropic hormone glucagon-like peptide-1-(7-37). J Biol Chem 274 14147-14156 Lipsius SL, Hiiser J, Blatter LA 2001 Intracellular Ca2+ release sparks atrial pacemaker activity. News Physiol Sci 16 101-106... 

Figure 3.4 also shows that fructose-2,6-bis phosphate (F2,6bisP) is an important allosteric regulator of PFK-1 this is partly because the turnover of F2,6bisP influenced by the hormone glucagon. F2,6bisP is synthesized from fructose-6-phosphate by PFK-2,... 

The hormones glucagon, cortisol and insulin regulate the concentrations of some enzymes and hence their activities. These include glucokinase, pyruvate kinase and phospho-enolpyruvate carboxykinase. Most work has been carried out on the carboxykinase enzyme, for which it is known that glucagon and cortisol increase the concentration whereas insulin decreases it. These changes are brought about at the transcriptional level by changing the activity of transcription factors (Chapter 20). Since the hormones... 

Hormones can modify the concentration of precursors, particularly the lipolytic hormones (growth hormone, glucagon, adrenaline) and cortisol. The lipolytic hormones stimulate lipolysis in adipose tissue so that they increase glycerol release and the glycerol is then available for gluconeogenesis. Cortisol increases protein degradation in muscle, which increases the release of amino acids (especially glutamine and alanine) from muscle (Chapter 18). 

Adrenaline Noradrenaline (+) Growth hormone Glucagon Insulin ... 

Cortical hormones include glucocorticoids (cortisol/corticosterone) and mineralocorticoids (aldosterone) medullar hormones are adrenaline and noradrenaline Pancreas Regulates glucose in blood via production of the hormones glucagon and insulin... 

Regulation by interconversion (bottom). If the blood glucose level falls, the peptide hormone glucagon is released. This activates... 

The incretin hormone glucagon-like peptide-1 (GLP-1) plays a crucial role in the regulation of insulin by acting on the pancreas to potentiate glucose-induced insulin secretion. GLP-1 is rapidly cleaved by serine protease dipeptidylpeptidase IV. The inhibitors of DDP-IV are new drugs for the oral treatment of type 2 diabetes. 

AC2993/pept. structurally correlated to the human hormone glucagon-like peptide-1... 

Hormones Glucagon, recombinant Glucagon for injection/ GlucaGen 3.5... 

Acetyl-CoA carboxylase is also regulated by covalent modification. Phosphorylation, triggered by the hormones glucagon and epinephrine, inactivates the enzyme and reduces its sensitivity to activation by citrate, thereby slowing fatty acid synthesis. In its active (dephosphorylated) form, acetyl-CoA carboxylase polymerizes into long filaments (Fig. 21-1 lb) phosphorylation is accompanied by dissociation into monomeric subunits and loss of activity. 

Site of synthesis The counterregulatory hormones Glucagon is a polypeptide hormone secreted by the a cells of the pancreatic islets. Glucagon, along with epinephrine, Cortisol, and growth hormone (the "counterregulatory hormones"), opposes many of the actions of insulin. 

The Coris found that the interconversion of phosphor-ylases a and b is catalyzed by another enzyme, and subsequent work by Earl Sutherland showed that this process is under hormonal control. In muscle, conversion of phosphorylase b to a is stimulated by epinephrine in liver, it is stimulated by both epinephrine and the pancreatic hormone glucagon. The structural basis for the difference between the two forms of phosphorylase remained unknown until the late 1950s, when Edwin Krebs and Edmund Fischer showed that phosphorylase a has a phosphate on serine 14. This phosphate is absent in the b form of the enzyme. Krebs and Fischer also showed that the kinase that catalyzes the addition of the phosphate is itself regulated by a phosphorylation catalyzed by another enzyme, the cAMP-dependent protein kinase ... 

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