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A kisspeptin-10 analog with greater in vivo bioactivity than kisspeptin-10.

Curtis AE, Cooke JH, Baxter JE, Parkinson JR, Bataveljic A, Ghatei MA, Bloom SR, Murphy KG - Am. J. Physiol. Endocrinol. Metab. (2009)

Bottom Line: The smallest endogenous kisspeptin, kisspeptin-10 (KP-10), binds to the receptor KISS1R with a similar affinity to the full-length peptide, kisspeptin-54 (KP-54), but is less effective in vivo, possibly because of increased enzymatic breakdown or clearance.In addition, 60 min postinjection, 0.15 nmol [dY](1)KP-10 significantly increased total testosterone levels in mice whereas the same dose of KP-10 had no significant effect.Should manipulation of the kisspeptin/KISS1R signaling system prove therapeutically useful, long-lasting analogs such as [dY](1)KP-10 may have greater therapeutic potential than endogenous forms of kisspeptin.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Investigative Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Rd., London W12 0NN, UK.

ABSTRACT
The kisspeptins are neuropeptides that stimulate the hypothalamo-pituitary-gonadal (HPG) axis. The smallest endogenous kisspeptin, kisspeptin-10 (KP-10), binds to the receptor KISS1R with a similar affinity to the full-length peptide, kisspeptin-54 (KP-54), but is less effective in vivo, possibly because of increased enzymatic breakdown or clearance. The kisspeptin system may have therapeutic potential in the treatment of reproductive disorders and endocrine cancers. We have rationally modified the structure of KP-10 and tested the binding affinity of these analogs for the KISS1R. Those analogs that bound with relatively high affinity to KISS1R were tested for ability to stimulate ERK1/2 phosphorylation in vitro and for their ability to stimulate the HPG axis in vivo. One analog, [dY](1)KP-10, bound to KISS1R with lower affinity to KP-10 and exhibited similar bioactivity in vitro. However, in vivo peripheral administration of [dY](1)KP-10 increased plasma LH and testosterone more potently than KP-10 itself at 20 min postinjection in mice. In addition, 60 min postinjection, 0.15 nmol [dY](1)KP-10 significantly increased total testosterone levels in mice whereas the same dose of KP-10 had no significant effect. Should manipulation of the kisspeptin/KISS1R signaling system prove therapeutically useful, long-lasting analogs such as [dY](1)KP-10 may have greater therapeutic potential than endogenous forms of kisspeptin.

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Competition binding curves for kisspeptin-10 (KP-10) and [dY]1KP-10 against [125I]KP-54 to the receptor KISS1R in Chinese hamster ovary (CHO) cells that had been stably transfected with the human KISS1R (CHO-KISS1R cells) cell membrane preparations. Binding assays were carried out in triplicate and repeated 3–5 times.
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Figure 1: Competition binding curves for kisspeptin-10 (KP-10) and [dY]1KP-10 against [125I]KP-54 to the receptor KISS1R in Chinese hamster ovary (CHO) cells that had been stably transfected with the human KISS1R (CHO-KISS1R cells) cell membrane preparations. Binding assays were carried out in triplicate and repeated 3–5 times.

Mentions: Initial receptor binding studies were carried out on analogs using membranes prepared from CHO-KISS1R cells. Binding studies produced an IC50 of 1.00 ± 0.34 nmol for KP-10 (Fig. 1). Initial analog binding studies showed that only one analog, ANA5, had an IC50 lower than that of KP-10 itself. Other analogs had IC50s ranging from 3.2 to 447 nM, and ANA10 did not bind at concentrations up to 200 nM. Subsequent studies suggested that ANA19 ([dY]1KP-10) was a KISS1R super agonist, and the receptor binding curve for [dY]1KP-10 is thus shown (Fig. 1).


A kisspeptin-10 analog with greater in vivo bioactivity than kisspeptin-10.

Curtis AE, Cooke JH, Baxter JE, Parkinson JR, Bataveljic A, Ghatei MA, Bloom SR, Murphy KG - Am. J. Physiol. Endocrinol. Metab. (2009)

Competition binding curves for kisspeptin-10 (KP-10) and [dY]1KP-10 against [125I]KP-54 to the receptor KISS1R in Chinese hamster ovary (CHO) cells that had been stably transfected with the human KISS1R (CHO-KISS1R cells) cell membrane preparations. Binding assays were carried out in triplicate and repeated 3–5 times.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2822479&req=5

Figure 1: Competition binding curves for kisspeptin-10 (KP-10) and [dY]1KP-10 against [125I]KP-54 to the receptor KISS1R in Chinese hamster ovary (CHO) cells that had been stably transfected with the human KISS1R (CHO-KISS1R cells) cell membrane preparations. Binding assays were carried out in triplicate and repeated 3–5 times.
Mentions: Initial receptor binding studies were carried out on analogs using membranes prepared from CHO-KISS1R cells. Binding studies produced an IC50 of 1.00 ± 0.34 nmol for KP-10 (Fig. 1). Initial analog binding studies showed that only one analog, ANA5, had an IC50 lower than that of KP-10 itself. Other analogs had IC50s ranging from 3.2 to 447 nM, and ANA10 did not bind at concentrations up to 200 nM. Subsequent studies suggested that ANA19 ([dY]1KP-10) was a KISS1R super agonist, and the receptor binding curve for [dY]1KP-10 is thus shown (Fig. 1).

Bottom Line: The smallest endogenous kisspeptin, kisspeptin-10 (KP-10), binds to the receptor KISS1R with a similar affinity to the full-length peptide, kisspeptin-54 (KP-54), but is less effective in vivo, possibly because of increased enzymatic breakdown or clearance.In addition, 60 min postinjection, 0.15 nmol [dY](1)KP-10 significantly increased total testosterone levels in mice whereas the same dose of KP-10 had no significant effect.Should manipulation of the kisspeptin/KISS1R signaling system prove therapeutically useful, long-lasting analogs such as [dY](1)KP-10 may have greater therapeutic potential than endogenous forms of kisspeptin.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Investigative Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Rd., London W12 0NN, UK.

ABSTRACT
The kisspeptins are neuropeptides that stimulate the hypothalamo-pituitary-gonadal (HPG) axis. The smallest endogenous kisspeptin, kisspeptin-10 (KP-10), binds to the receptor KISS1R with a similar affinity to the full-length peptide, kisspeptin-54 (KP-54), but is less effective in vivo, possibly because of increased enzymatic breakdown or clearance. The kisspeptin system may have therapeutic potential in the treatment of reproductive disorders and endocrine cancers. We have rationally modified the structure of KP-10 and tested the binding affinity of these analogs for the KISS1R. Those analogs that bound with relatively high affinity to KISS1R were tested for ability to stimulate ERK1/2 phosphorylation in vitro and for their ability to stimulate the HPG axis in vivo. One analog, [dY](1)KP-10, bound to KISS1R with lower affinity to KP-10 and exhibited similar bioactivity in vitro. However, in vivo peripheral administration of [dY](1)KP-10 increased plasma LH and testosterone more potently than KP-10 itself at 20 min postinjection in mice. In addition, 60 min postinjection, 0.15 nmol [dY](1)KP-10 significantly increased total testosterone levels in mice whereas the same dose of KP-10 had no significant effect. Should manipulation of the kisspeptin/KISS1R signaling system prove therapeutically useful, long-lasting analogs such as [dY](1)KP-10 may have greater therapeutic potential than endogenous forms of kisspeptin.

Show MeSH
Related in: MedlinePlus