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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
9
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pubmed:dateCreated |
1984-10-3
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pubmed:abstractText |
In previous work we reported that [Cys4,Cys10]-alpha-MSH (II) and Ac-[Cys4,Cys10]-alpha-MSH4-13-NH2 (III) were superpotent melanotropins. Ac-[Cys4,Cys10]-alpha-MSH4-10-NH2 (VI), which constitutes the cyclic analogue of the putative active site sequence -Met4-Glu5-His6-Phe7-Arg8-Trp9-Gly10- of alpha-MSH, was much less active. In the present investigation the contribution of the Lys11 and Pro12 residues of the C-terminal carboxamide tripeptide -Lys11-Pro12-Val13-NH2 to the potency of Cys4,Cys10 containing cyclic melanotropins was studied. Ac-[Cys4,Cys10]-alpha-MSH4-11-NH2 (V) was less potent than alpha-MSH in the frog and lizard skin bioassays and the mouse S-91 (Cloudman) melanoma adenylate cyclase assay but more potent than Ac-[Cys4,Cys10]-alpha-MSH4-10-NH2 in the three assays studied. Ac-[Cys4,Cys10]-alpha-MSH4-12-NH2 (IV) was considerably more potent than the cyclic 4-11 melanotropin and was, in fact, equipotent or even slightly more potent than [Cys4,Cys10]-alpha-MSH and Ac-[Cys4,Cys10]-alpha-MSH4-13-NH2 over the linear portion of the dose-response in all three bioassays. These results demonstrate that Lys11 and Pro12 but to a lesser extent Val13 of the C-terminal tripeptide sequence contributes to the potency of the cyclic melanotropins. The further substitution of a D-Phe7 for the L-Phe7 residue into the cyclic 4-12 analogue resulted in a highly potent compound Ac-[Cys4,D-Phe7,Cys10]-alpha-MSH4-12-NH2 (VII) that exhibited highly prolonged biological activity.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0022-2623
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
27
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1186-90
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:6332195-Adenylate Cyclase,
pubmed-meshheading:6332195-Amino Acid Sequence,
pubmed-meshheading:6332195-Animals,
pubmed-meshheading:6332195-Hormones,
pubmed-meshheading:6332195-Lizards,
pubmed-meshheading:6332195-Melanocyte-Stimulating Hormones,
pubmed-meshheading:6332195-Peptides, Cyclic,
pubmed-meshheading:6332195-Rana pipiens,
pubmed-meshheading:6332195-Structure-Activity Relationship
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pubmed:year |
1984
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pubmed:articleTitle |
Cyclic melanotropins. 5. Importance of the C-terminal tripeptide (Lys-Pro-Val).
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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