Growth hormone structure

Somatotropin (STH) (Growth hormone, GH somatotrophic hormone hypophyseal growth hormone) Structure Known and synthesized coiled, unbranched Promotes general growth of organism Promotes skeletal growth, protein anabolism, fat metabolism, carbohydrate metabolism, water, and salt meiabolism Relates with all vitamins in connection with growth actions... 

The growth hormone structure established the architecture of the site I and II interactions in a homodimeric receptor complex. The viral and human IL-6 complexes with gplSO extend this paradigm to heterodimeric complexes but also elaborate the modular epitope concept by adding the site III. It is clear from the gplSO complexes that in the case of the HHV-8 IL-6, a site II is used for the gplSO GHR contact. In the human structure, a site I is used for the a. receptor and a site II is used for the gplSO GHR interaction. Similar to GH, in the human IL-6 structure, precomplexation... 

Somatostatin is a tetradecapeptide of the hypothalamus that inhibits the release of pituitary growth hormone Its ammo acid sequence has been determined by a combination of Edman degradations and enzymic hydrolysis expenments On the basis of the following data deduce the pnmary structure of somatostatin... 

Figure 3.7 The polypeptide chains of cytochrome bs62 and human growth hormone both form four-helix-bundle structures.

Figure 13.18 Ribbon diagram of the structure of human growth hormone. The fold is a four-helix bundle with up-up-down-down topology, and consequently there are two long cross-connections between helices A and B as well as between helices C and D. (Adapted from J. Wells et al., Annu. Rev. Biochem.

Figure 13.20 Ribbon diagram of the structure of a 1 2 complex between the human growth hormone and the extracellular domains of two receptor molecules. The two receptor molecules (blue) bind the hormone (red) with essentially the same loop regions (yellow).

The prolactin receptor, PER, which regulates milk production in mammals, belongs to the same receptor class as the growth hormone receptor. In addition to binding the hormone prolactin, PER also binds and is activated by growth hormone. The extracellular domain of PER forms a very stable 1 1 complex with growth hormone in solution this complex has been crystallized and its structure determined (Figure 13.21). We shall compare this structure with the 1 2 complex of the same hormone with GHR. 

De Vos, A.M., Ultsch, M., Kossiakoff, A.A. Human growth hormone and extracellular domain of its receptor crystal structure of the complex. Science 255 306-312,... 

Structural Formula Proteins of molecular weights ranging from 22,124 for human growth hormone (HGH to 47,400 for bovine growth hormone. 

H. A. Havel, R. S. Chao, R. J. Haskell, and T. J. Thamann. Investigation of protein structure with optical spectroscopy Bovine growth hormone, Anal. Chem., 61, 642 (1989). 

The recruitment of zinc for a structural role, or to activate an enzyme, has been observed. The zinc ion induces the dimerization of human growth hormone (hGH), with two Zn ions associated per dimer of hGH. This is confirmed by replacement of possible zinc binding residues resulting in weakened binding of the zinc ion. Formation of a zinc-hGH dimeric complex may be important for storage of hGH in secretory granules.975 In a toxic role, anthrax lethal factor is one of the three components of the secreted toxin and is a zinc-dependent protease that cleaves a protein kinase and causes lysis of macrophages.976... 

Scheme 1. Molecular structure of the plant growth hormone auxin (indoleacetic acid, IAA). Extremely small amounts (nanomolar) can be detected by the auxin standard test 5 mm long segments of pea shoots elongate faster in the presence of exogenous auxin, which can be taken as a sensitive assay...

A vast number of hormones and neurotransmitters are synthesized from simple structural units including chains of amino acids. Among the amino acid based hormones are comparatively large protein molecules such as prolactin, growth hormone and insulin, and shorter chains of amino acids which may form peptide hormones, such as oxytocin and vasopressin. Protein based hormones are essential for metabolism, growth and some components of reproduction. However, evidence for specific influences of these compounds on human behavior is limited. 

Pearce, K.H., Jr., M.H. Ultsch, R.F. Kelley, A.M. de Vos, and J.A. Wells. 1996. Structural and mutational analysis of affinity-inert contact residues at the growth hormone-receptor interface. Biochemistry 35 10300-10307. 

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