Heat–alkali treatment of synthetic α- and β-melanocyte-stimulating hormones (MSH), known to cause racemization of amino acids within the peptides, results in prolongation of the darkening (melanophore dispersion) effect of these hormones on frog and lizard skins in vitro. Skins remain darkened for hours or even days if supramaximal concentrations of the racemized hormones are used. This response can be partially reversed by melatonin or noradrenaline. Heat–alkali treatment of α-MSH at either 60 or 97 °C results in a retardation of the response of the skins to the racemized peptides. In contrast, the response of frog skins to heat–alkali-treated β-MSH is immediately enhanced and potentiated. Heat–alkali treatment also prolongs and potentiates the activity of synthetic [des-acetyl]-α-MSH (in contrast to the retardation effect on the natural acetylated peptide). These data suggest a role for the N-acetyl group in the retardation phenomenon. The activity of synthetic [2-d-tyrosine]-α-MSH is much lower than that of α-MSH itself, indicating that heat–alkali treatment of the hormone may produce either potentiation or partial inactivation of the peptide, depending on the site of racemization.
Journal of Endocrinology is committed to supporting researchers in demonstrating the impact of their articles published in the journal.
The two types of article metrics we measure are (i) more traditional full-text views and pdf downloads, and (ii) Altmetric data, which shows the wider impact of articles in a range of non-traditional sources, such as social media.
More information is on the Reasons to publish page.
| Sept 2018 onwards | Past Year | Past 30 Days | |
|---|---|---|---|
| Full Text Views | 5 | 2 | 0 |
| PDF Downloads | 4 | 0 | 0 |
Online ISSN: 1479-6805
Print ISSN: 0022-0795
Strengthening biomedical communities
to advance science and health
CONTACT US
Bioscientifica Ltd | Starling House | 1600 Bristol Parkway North | Bristol BS34 8YU | UK
Bioscientifica Ltd | Registered in England no 3190519
