Lipolytic activity of Met-Arg-His-Phe-Arg-Trp-Gly, a synthetic analog of the ACTH (4-10) core sequence

Draper, Michael W.; Merrifield, R. B.; Rizack, Martin A.

doi:10.1021/jm00270a003

Cited by 19 publications

(15 citation statements)

References 14 publications

(15 reference statements)

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“…Structure function studies on melanocortin peptides from the early 1970s using stimulation of lipolysis as a criterion for biological potency revealed that the heptapeptide core sequence exerts biological activity. An amino acid exchange from Glu to Arg in the ACTH core sequence resulted in a fourfold increased activity on the release of FFAs compared to the natural ACTH core sequence (Draper et al, 1973). As lipolysis is an essential prerequisite for the activation of UCP1, we included both the natural and the synthetic version of the ACTH fragment in our study.…”

Section: Resultsmentioning

confidence: 99%

Opposing Actions of Adrenocorticotropic Hormone and Glucocorticoids on UCP1-Mediated Respiration in Brown Adipocytes

Schnabl

Westermeier

et al. 2019

Front. Physiol.

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Brown fat is a potential target in the treatment of metabolic disorders as recruitment and activation of this thermogenic organ increases energy expenditure and promotes satiation. A large variety of G-protein coupled receptors, known as classical drug targets in pharmacotherapy, is expressed in brown adipocytes. In the present study, we analyzed transcriptome data for the expression of these receptors to identify potential pathways for the recruitment and activation of thermogenic capacity in brown fat. Our analysis revealed 12 Gs-coupled receptors abundantly expressed in murine brown fat. We screened ligands for these receptors in brown adipocytes for their ability to stimulate UCP1-mediated respiration and Ucp1 gene expression. Adrenocorticotropic hormone (ACTH), a ligand for the melanocortin 2 receptor (MC2R), turned out to be the most potent activator of UCP1 whereas its capability to stimulate Ucp1 gene expression was comparably low. Adrenocorticotropic hormone is the glandotropic hormone of the endocrine hypothalamus–pituitary–adrenal-axis stimulating the release of glucocorticoids in response to stress. In primary brown adipocytes ACTH acutely increased the cellular respiration rate similar to isoproterenol, a β-adrenergic receptor agonist. The effect of ACTH on brown adipocyte respiration was mediated via the MC2R as confirmed by using an antagonist. Inhibitor-based studies revealed that ACTH-induced respiration was dependent on protein kinase A and lipolysis, compatible with a rise of intracellular cAMP in response to ACTH. Furthermore, it is dependent on UCP1, as cells from UCP1-knockout mice did not respond. Taken together, ACTH is a non-adrenergic activator of murine brown adipocytes, initiating the canonical adenylyl cyclase–cAMP–protein kinase A-lipolysis-UCP1 pathway, and thus a potential target for the recruitment and activation of thermogenic capacity. Based on these findings in primary cell culture, the physiological significance might be that cold-induced ACTH in concert with norepinephrine released from sympathetic nerves contributes to BAT thermogenesis. Notably, dexamethasone attenuated isoproterenol-induced respiration. This effect increased gradually with the duration of pretreatment. In vivo, glucocorticoid release triggered by ACTH might oppose beta-adrenergic stimulation of metabolic fuel combustion in BAT and limit stress-induced hyperthermia.

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Section: Resultsmentioning

confidence: 99%

Opposing Actions of Adrenocorticotropic Hormone and Glucocorticoids on UCP1-Mediated Respiration in Brown Adipocytes

Schnabl

Westermeier

et al. 2019

Front. Physiol.

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“…They found that this lipolytic activity, which is evident with rabbit tissue, was less noticeable for rat adipocytes but was not shown by (l-lO)ACTH. According to Draper, Merrifield & Rizack (1973a, b) it is the 6-10 sequence of ACTH which is the essential portion of the peptide in vitro; the other amino acids only increase its activity.…”

Section: Resultsmentioning

confidence: 99%

In-vivo hypocalcaemic, hypophosphataemic and hyperlipaemic activities in the common peptide sequence of adrenocorticotrophin, melanocyte-stimulating hormone and lipotrophin

Drouhault¹,

Valéro²,

Baghdiantz³

et al. 1983

Journal of Endocrinology

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A heptapeptide solution in acetate buffer (pH = 4, 150 micrograms/kg) of the amino acid sequence common to ACTH, alpha- and beta-MSH and lipotrophin, when injected intravenously into rabbits produced an increase in total lipids, cholesterol and free fatty acids after 1 h and a decrease in plasma calcium and phosphate after 2 h. No significant modification in the amount of creatinine, uric acid, urea, total proteins, CO2, Cl-, K+ or Na+ was observed.

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“…A double coupling protocol was used (NMP-HOBT) with a capping step following the recoupling as part of the protocol. To protect against undesired acid-catalyzed oxidations of cysteine and methionine (30) during trifluoroacetic acid deblocking, 1.0% (w/v) dithioerythritol was added to the trifluoroacetic acid as a scavenger. Introduction of the NH 2 -terminal acetyl group was carried out by coupling acetic acid (2 mmol).…”

Section: Materials-[␥-mentioning

confidence: 99%

Biochemical and Biophysical Comparison of Native and Chemically Synthesized Phospholamban and a Monomeric Phospholamban Analog

Mayer

McKenna

Garsky

et al. 1996

Journal of Biological Chemistry

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Phospholamban (PLB) was rapidly isolated from canine cardiac sarcoplasmic reticulum using immunoaffinity chromatography and prepared by solid phase peptide synthesis. The two proteins are indistinguishable when analyzed by SDS-polyacrylamide gel electrophoresis and exhibit pentameric oligomeric states. They are similarly detected on Western blots, are phosphorylation substrates, have identical amino acid compositions that directly reflect their predicted values, yield the same internal amino acid sequences upon CNBr digestion, and have molecular mass values agreeing with the expected value (ϳ6123 Da). Native and synthetic PLB reduced the calcium sensitivity of Ca 2؉ATPase, which is reversed by anti-PLB antibody. A Cys-to-Ser PLB analog, where the cysteines (36, 41, and 46) were substituted by serines, is monomeric on SDS-polyacrylamide gel electrophoresis, can be phosphorylated, and is recognized by polyclonal antisera. PLB migrates with a sedimentation coefficient of 4.8 S in sedimentation velocity ultracentrifugation experiments, whereas Cys-toSer PLB does not sediment, consistent with a monomeric state. Circular dichroism spectral analysis of PLB indicates about 70% ␣-helical structure, whereas Cys-toSer PLB manifests only about 30%. Because the physiochemical properties of native and synthetic PLB appear identical, the more readily available synthetic protein should be suitable for more extensive structural studies. Phospholamban (PLB)1 is an oligomeric membrane protein present in stoichiometric amounts associated with the Ca 2ϩ ATPase of cardiac sarcoplasmic reticulum (SR). PLB in its unphosphorylated state attenuates the catalytic activity of the Ca 2ϩ ATPase by reducing its apparent calcium sensitivity. Phosphorylation of PLB (1-3), treatment with antibodies directed against PLB (4 -7), or mild trypsin proteolysis of PLB (8) ATPase activity. Data supporting reversible and direct regulation of the calcium pump by PLB are abundant, yet the detailed mechanistic and structural requirements for PLB inhibition remain to be described.The primary structure of PLB has been deduced from its cDNA (15). It is highly conserved among species, has an acetylated amino terminus, and consists of 52 amino acids with a predicted molecular mass of 6123 Da. Several secondary structure models (an example is shown in Fig. 1) have been proposed (13,14,16) with the following general features: (i) PLB is an amphipathic peptide with a hydrophilic NH 2 terminus, part of which is predicted to form an ␣-helix whose exact length and position are uncertain, (ii) serine 16 and threonine 17 are the sites for protein phosphorylation by cAMP-dependent protein kinase (PKA) and calcium-calmodulin-dependent protein kinase, respectively, and (iii) the hydrophobic COOH-terminal amino acids (31-52) form a transmembrane ␣-helical segment and are involved in protein oligomerization. The quaternary structure of PLB under nondenaturing conditions is assumed to be pentameric. PLB migrates as a homopentamer with an apparent M r of 28,000 in SDS-PAGE, w...

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Lipolytic activity of Met-Arg-His-Phe-Arg-Trp-Gly, a synthetic analog of the ACTH (4-10) core sequence

Abstract: Ein neues ACTH‐(4 ‐ 10)‐Heptapeptid‐Analogon der Struktur (I) wird unter Anwe dung der Festkörpermethode hergestellt.

Cited by 19 publications

References 14 publications

Opposing Actions of Adrenocorticotropic Hormone and Glucocorticoids on UCP1-Mediated Respiration in Brown Adipocytes

Opposing Actions of Adrenocorticotropic Hormone and Glucocorticoids on UCP1-Mediated Respiration in Brown Adipocytes

In-vivo hypocalcaemic, hypophosphataemic and hyperlipaemic activities in the common peptide sequence of adrenocorticotrophin, melanocyte-stimulating hormone and lipotrophin

Biochemical and Biophysical Comparison of Native and Chemically Synthesized Phospholamban and a Monomeric Phospholamban Analog

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