On the conformation of thyrotropin releasing hormone

Sievertsson, Hans; Castensson, Staffan; Bowers, Cyril Y.

doi:10.1016/0014-5793(74)80760-x

Cited by 8 publications

(5 citation statements)

References 11 publications

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“…Somatomedin B is another growth-hormone-dependent polypeptide that has been purified from human plasma [3,4]. It was defined as an acidic peptide that stimulated [3H]thymidine incorporation into the DNA of human glial cells in culture [25].…”

Section: Comparison With Somatomedin Bmentioning

confidence: 99%

“…been purified from human plasma, using different purification procedures and different bioassays. These putative somatomedins include : somatomedin A [2,3], somatomedin B [3,4], somatomedin C [5], and nonsuppressible insulin-like activity (NSILA I and I1…”

mentioning

confidence: 99%

“…These putative somatomedins include : somatomedin A [2,3], somatomedin B [3,4], somatomedin C [5], and nonsuppressible insulin-like activity (NSILA I and I1…”

mentioning

confidence: 99%

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Purified Human Somatomedin A and Rat Multiplication Stimulating Activity

Rechler

Fryklund

Nissley

et al. 1978

European Journal of Biochemistry

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We have compared the mitogenic activity and reactivity in receptor binding assays of somatomedin A and multiplication-stimulating activity (MSA), two acid-soluble polypeptides of molecular weight 7-10000 that possess weak intrinsic insulin-like metabolic activity. Somatomedin A was purified to homogeneity from human plasma, and MSA was purified to homogeneity from the conditioned culture media of a cell line, BRL 3A, derived from rat liver. The two peptides stimulated DNA synthesis in chick embryo fibroblasts 3 -4-fold and have superimposable doseresponse curves. Addition of either peptide to chick embryo fibroblasts plated in serum-free medium increased the cell number by 150 in 4 days, compared with an increase of 25 % in control cultures receiving no additions. The two peptides also stimulated DNA synthesis in human fibroblasts in culture 3 -4-fold.Specific receptors for MSA and/or somatomedin A could be demonstrated in intact cells or membranes from chick embryo fibroblasts, human fibroblasts, human placenta, rat liver, and the BRL 3A2 cell line, a subclone of the line that produces MSA. Unlabeled MSA and somatomedin A inhibited the binding of '251-labeled MSA and '251-labeled somatomedin A to each of these receptors with comparable potency. In chick embryo fibroblasts, human fibroblasts, and human placental membranes, the binding of both radioactive ligands also was inhibited by insulin, consistent with the interpretation that lz5I-1abeled MSA and '251-labeled somatomedin A were binding to the same receptor. By contrast, in the BRL 3A2 cell line, insulin inhibited the binding of '251-labeled somatomedin A, but not the binding of '251-labeled MSA, suggesting that the two labeled peptides were binding to different receptors in this cell line. Moreover, '251-labeled MSA, but not '251-labeled somatomedin A, bound specifically to rat liver plasma membranes. These results indicate that human somatomedin A and rat MSA are closely related, but not identical, peptides. They have similar mitogenic activity for cultured fibroblasts, and cross-react with specific cell receptors with comparable potency. The two radioactively labeled peptides, however, can be distinguished by certain cell surface receptors for somatomedin-like peptides.The growth-promoting actions of growth hormone on its target tissues are thought to be mediated by substances in plasma that have been designated somatomedins [ 11. Several growth hormone-dependent polypeptides with properties of somatomedins have Abhreviarions.

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Section: Comparison With Somatomedin Bmentioning

confidence: 99%

mentioning

confidence: 99%

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Purified Human Somatomedin A and Rat Multiplication Stimulating Activity

Rechler

Fryklund

Nissley

et al. 1978

European Journal of Biochemistry

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“…The combined organic extracts were washed with water (30 ml), dried (Na,SO,), and evaporated to yield the monoacid-monoether (29) as a brown oil (2.97 g, 74%) which was used without purification. GH(CDC13, 90 MHz) 1.18 (3 H, t, CH,CH,), 1.42 ( 9H, s, Bu'), 3 (30).-The preceding monoacid-monoester (29) (2.97 g, 6.46 mmol) was dissolved in dioxane (100 ml) and the solution was refluxed for 16 h. The dioxane was evaporated and the brown oily residue was purified by column chromatography on silica (60-120 mesh, 50 g) using methylene dichloride as eluant. The appropriate fractions were combined and evaporated to afford (30) as a pale orange oil (2.67 g, 99%).…”

Section: ~~-N-acetyl-p-2-furylafaninementioning

confidence: 99%

“…Modification of the central residue of TRH has previously been shown to lead to drastic effects on the biological activity. [(N3'"-Me-His)*]-TRH (2) * is 8 times more active and [P-(pyrazolyl-1)-ala2]-TRH (4), is 1.5 times more active than TRH in releasing TSH although the isomeric [(N""-M~-H~s)~]-TRH (3) and [P-(pyrazolyl-3)-ala2]-TRH (5) analogues have only low activity (5% and 0.04%, respectively). pGlu-Thi-Pro-NH2(Thi2-TRH) (6) is less active than the parent peptide.…”

mentioning

confidence: 99%

Synthesis of heteroaromatic thyrotropin-releasing hormone analogues

Bladon¹

1990

J. Chem. Soc., Perkin Trans. 1

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Novel thyrotropin-releasing hormone (TRH) analogues containing the unnatural and heteroaromatic L-pyrrolylalanine, D-pyrrolylalanine, and L-furylalanine amino acids in position 2 have been synthesised. L-Furylalanine was obtained by the stereospecific hydrolysis of the N-acetyl-D,Lamino acid with acylase I. A protected derivative of D,L-pyrrolylalanine was prepared, the racemate was incorporated into the tripeptide and the LLL and LDL diastereoisomers were separated at the end of the synthesis.

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Hypothalamus-Regulationshormone

Voelter

1977

Fortschritte Der Chemie Organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products

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On the conformation of thyrotropin releasing hormone

Cited by 8 publications

References 11 publications

Purified Human Somatomedin A and Rat Multiplication Stimulating Activity

Purified Human Somatomedin A and Rat Multiplication Stimulating Activity

Synthesis of heteroaromatic thyrotropin-releasing hormone analogues

Hypothalamus-Regulationshormone

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