2023.08.03.61
Files > Volume 8 > Vol 8 No 3 2023

Structural analysis and cytotoxic evaluation of
kisspeptin10 and analogs in types of cancer

1 Programa de Medicina, Facultad de Ciencias
de la Salud, Universidad Autonoma de Bucaramanga; [email protected]
2 Instituto de Investigación Masira, Facultad
de Ciencias Médicas y de la Salud, Universidad de Santander; [email protected]
* Correspondence: [email protected]
Available
from: http://dx.doi.org/10.21931/RB/2023.08.03.61
ABSTRACT
The Kisspeptin system is a peptidergic system that plays a crucial role
in regulating of reproduction and
hormonal function. Kisspeptin is a peptide synthesized from the KiSS-1 gene and
has been identified as the endogenous ligand of the kisspeptin receptor (KISS1R
or GPR54 receptor). This system plays a key role in activating sex hormone secretion and puberty.
In addition to its function in the regulation of reproduction, the Kisspeptin
system has been found to play a role in other physiological processes, such as
the regulation of appetite, energy metabolism, cardiovascular function, and
cancer. In this study, several Kisspeptin analogs with structural modifications
were designed and synthesized. The Kisspeptin analogs were evaluated by in vitro cytotoxicity tests on cancer
cells of different cancer types. Cell viability assays were performed, and the
concentrations that inhibited cell growth by a significant percentage were
determined. The results showed that certain Kisspeptin analogs exhibited
increased selective cytotoxicity in cancer cells compared to healthy cells.
In conclusion, this study demonstrates that
structurally modified Kisspeptin analogs have the potential to be therapeutic
agents against some types of cancer. Understanding the structure-activity
relationship of these analogs and their evaluation of their selective toxicity
on cancer cells will be of great importance.
Keywords: Kisspeptins
Analogs, GPR54, Cancer, Cytotoxicity, Molecular Docking, Structure-activity
relationship, Anticancer therapy, Drug Design.
INTRODUCTION
The
Kiss1R receptor, or GPR54, was discovered and cloned from the rat brain in 19991. In humans, it was mapped
on chromosome 19p13.3, encoding a protein of 396 amino acids (75 kDa)2,3. It is widely distributed
throughout the central nervous system3 High levels of Kiss1R have
been observed in the cerebral cortex, cerebellum, thalamus, and medulla3 Peripherally has been
detected in the heart, skeletal muscle, kidney, liver, and placenta2-4 Kisspeptins (KPs), the
physiological ligand for the Kiss1R receptor was identified by several groups
in 20011,3,4. KPs are several
structurally related amidated peptides derived from the differential
proteolytic processing of a common precursor of 145 amino acids encoded by the
KISS1 gene. The Kiss1R activation leads to regulate the gonadotropin-releasing
hormone (GnRH) secretion5, leading to the regulation
of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the
pituitary gland6-8.
Emerging
evidence suggests that Kisspeptin plays a crucial role in the development of
suppression of metastasis. The metastatic suppressor activity of the kisspeptin
system was first observed in melanoma9, where the low levels of
KissR expression lead to increased metastasis risks. It has been shown that the
role of the KP system is not only limited to this type of cancer but has
expanded to other cancers as well. Martin et al.,10 conclude that KP may be
directly associated with the aggressiveness of breast cancer and may be
pro-invasive in breast tumors. In pancreatic cancer, several authors11-13 suggest that the most
damaging aspect of the disease can be predicted and, in some cases, prevented
by the KP system, as they observed significant differences in the expression of
KISS1 and Kiss1R in healthy and pancreatic cancer cells. Concerning ovarian and
endometrial cancer, the KP system improves the prognosis of these patients due
to its metastasis suppressor activity14-16. Another interesting
approach is in gastric cancer, where high blood levels of kp54 in early-stage
gastric cancer patients suggest a possibility that kp54 may function as a
marker for diagnosis of this disease17, as well as overexpression
of the KiSS-1 inhibits cell growth, proliferation, and invasion in gastric
carcinoma cells, proving the antimetastatic potential of kisspeptin17-19. Finally, in prostate
cancer, KiSS-1 expression levels were significantly higher in benign prostate
cells compared with primary and metastatic prostate cancer cells. Therefore, it
is speculated that KiSS-1 may be used as an essential prostate cancer marker
since it can be used to monitor the transformation of benign disease to
malignancy20-22.
This
paper will study the structure-activity relationship of Kisspeptin-10 analogs
and evaluate their cytotoxicity, specifically in cancer cells. It seeks to
understand how structural modifications in Kisspeptin-10 analogs may influence
their antitumor activity and their ability to induce cell death in cancer cell
lines. Through in vitro cytotoxicity
tests, the viability and response of cancer cells to these analogs were
evaluated, which will allow the identification of those with the most
significant therapeutic potential.
MATERIALS AND METHODS
AlaScan with Molecular
Docking
The 3D structure of the
KissR receptor was predicted using AlphaFold2 of ColabFold23, and the quality of the
best-predicted model was checked with ProSA-web online tool 24. The design of the
Kisspeptin peptide was expected with the PEP-FOLD3 online tool 25, and the top model of
the best cluster was selected as the initial model. The kisspeptin peptide was
located in the outer membrane domain of the KissR receptor, and each residue of
the peptide was mutated to Alanine by using the mutagenesis option of the Pymol
tool26. In total, 11 molecular
docking simulations were performed, i.e., one with the native peptide and one
for each mutated residue. The molecular docking simulations were performed with
the FlexPepDock server 27, allowing the peptide's
flexibility during the simulations. The possible molecular interactions of the
top 3 models for each docking simulation were analyzed with Prodigy online tool28 and BIOVIA Discovery
Studio Software29.
Synthesis and chemical
characterization of peptides
Each KP10 analog (See Table
1.) was manually assembled on 100 mg of Rink resin using the HBTU/HOBt
activation protocol for Fmoc solid-phase peptide synthesis30. In summary, the
N-terminal protecting group was removed with 20% piperidine. Previously, the
amino acids were activated with HOBt/HBTU 0.45M, and couplings were carried out
in the presence of DIPEA 1.2M and microwave irradiation. The 1% TNBS test monitored
the correct coupling and deprotection. Finally, the peptide was cleaved from
the resin with 90%TFA, and Sep Pak C18 reverse phase columns purified peptides.
The peptide identification was performed on a Bruker ultra extreme mass
spectrometer with 40,000 FWHM resolution, 1 ppm accuracy, 337 nm laser, and a
mass range of 500 to 3000 Da in positive mode using SCiLs Lab for MS Imaging
software. A supersaturated 2,5-dihydroxybenzoic acid (DHB) solution in ACN/H2O
30:70 with 0.1% TFA was used as a matrix.
Cell Culture
The Universidad
Industrial de Santander kindly donated Cervical Adenocarcinoma (HeLa) and
Prostate Adenocarcinoma (PC3) cells. HEK293T was provided by Biopetrolabs
(ECACC 12022001, Culture Collection). HeLa and HEK293 cells were grown in
Dulbecco's Modified Eagle Medium (DMEM – Invitrogen) with 10% fetal bovine
serum (FBS – Invitrogen), 100 U/ml penicillin and 100 mg streptomycin at 37ºC
in a humidified atmosphere (95% air and 5% CO2). PC3 cells were cultured in
Roswell Park Memorial Institute (RPMI) medium with 10% fetal bovine serum (FBS
– Invitrogen), 100 U/ml penicillin, and 100 mg streptomycin at 37ºC in a
humidified atmosphere (95% air and 5% CO2).
Cytotoxicity MTT assay
In 96-well culture
plates (Greiner, Fisher Scientific), 15000 cells/well were seeded in a fully
supplemented medium according to the manufacturer protocol (Abcam) and kept at
37°C. After 24 hours, cells were serum starved and then stimulated with 10,
100, 250 and 500 nM KP10 and analogs for 48 hours. MTT solution (100 uL, 0.5
mg/ml) was added to each well, and the plate was incubated at 37°C for 3h,
followed by the addition of MTT solvent, then the plate for 15 minutes. The
product was quantified by measuring absorbance at 590 nm using a microplate
reader RT-2100C from BioTech. The data were analyzed with the GraphPad Prism 8.0
software.
RESULTS
Structure-activity
relationship assessment of kisspeptin10 analogs and evaluation of cytotoxicity
in cancers is an important research topic in pharmacology and oncology.
Structure-activity relationship assessment is an approach used to understand
how modifications in the chemical structure of a molecule affect its biological
activity. In the case of kisspeptin10 analogs, we seek to determine how this
molecule's structure affects its ability to inhibit cancer cell growth.
Evaluating cytotoxicity in cancer
types is another crucial aspect of this research. Cytotoxicity refers to the
ability of a substance to damage or destroy cells. In the context of cancer,
cytotoxicity assessment involves determining whether kisspeptin10 analogs can
selectively kill cancer cells without harming healthy cells.
Synthesis and chemical characterization of Kisspeptin 10 analogs.
Eleven kisspeptin10 analogs were
initially synthesized, where the amino acid alanine substitution was performed
for each amino acid present. This allowed us to perform a screening on the
different properties provided by the side chain of the other amino acids and
how they can contribute to the interaction with the receptor.

Table 1. Sequences of peptides synthesized and used

Table 2. Mass spectrometry data.
mass-to-charge ratio (m/z) of the [M+H]+ ions of each synthesized peptide.
For all peptides, the molecular weight observed by MS analysis was consistent
with the theoretical value (Table 2.)
Evaluation of structure-activity relationships through molecular
docking
Evaluating the structure-activity
of kisspeptin analogs by molecular docking has proven a powerful tool in
pharmacological research. Molecular docking is a computational method that
predicts the interaction between a small molecule (ligand) and a macromolecule
(receptor) at the molecular level. In the case of kisspeptin analogs, molecular
docking is used to predict how these compounds bind and match their target
receptor, providing information about their biological activity and potential
as therapeutic agents.
Values such as the interface score, which indicates the sum
of the energy of the interface residues between kisspeptin analogs and Kiss1R, help
select those models with a more extensive interface of interaction, i.e., those
models with a more negative value. Moreover, matters such as the predicted
binding affinity ΔG, the dissociation constant (Kd), and the percentage of
non-interacting surfaces (NIS) charged and apolar also give valuable
information about the critical strength between the two molecules in the
complexes. Hence, Table 3 shows the values obtained for the top 3 models
predicted by the FlexPepDock server. In the case of the interface score, the
best deal was acquired by an Ala8-KP10 model (–17.686). The best
values were obtained by Ala1-KP10 and Ala3-KP10 models for the predicted
binding affinity and the dissociation constant. Finally, the values of the
non-interacting surfaces were very similar for all kisspeptin analogs.

Table 3. Results of the top 3 models according to the interface score (I_sc)
predicted by FlexPepDock.
Cytotoxicity Evaluation
All the
peptides were subjected to toxicity assay via concentration-response assays on
cervix and prostate cancer cell lines. Among these peptides, Ala3-KP10
and Ala4-KP10 demonstrated maximum efficacy against HeLa cells
(cervix cancer) with IC50 values of 0.24 ± 0,08 and 0.35 ± 0,08 nM,
respectively (as presented in Table 4). Meanwhile, the peptide Ala2-KP10
significantly affected HeLa cells with an IC50 of 3.7 ± 1,25 nM.
Conversely, the analogs Ala5-KP10 through Ala10-KP10 only
exhibited cytotoxic activity at 500 nM concentrations, limiting their viability
under normal physiological conditions (See Figure 1.). The IC50
values for these analogs ranged between 0.27 to 0.41.
In the case of prostate cancer,
it can be observed that analogs Ala5-KP10, Ala8-KP10, and
Ala10-KP10 achieve high cytotoxicity (IC50 0,16 ± 0,08,
0,14 ± 0,05, 0,05 ± 0,02 respectively). The other analogs show cytotoxicity
only at the highest concentration (500 nM). The control of healthy cells was
performed in HEK293 (human embryonal kidney) cells, where no traces of
cytotoxicity were found with KP10 or any of the tested peptides.

Figure 1. Viability of HeLa cells after stimulation with KP10 and analogs at concentrations
of 10, 100, 250 and 500 nM. Viability was measured after 48 hours of incubation
with the peptides.

Figure 2. Viability of PC3 cells after stimulation with KP10 and analogs at
concentrations of 10, 100, 250 and 500 nM. Viability was measured after 48
hours of incubation with the peptides.

Table 4. The IC50 values of
KP10 and analogs on human cancer cell lines and a healthy cell line.
DISCUSSION
Cytotoxicity assays and molecular
docking analyses of a series of kisspeptin analogs were performed to evaluate
their potential as anticancer therapeutics. The results of the cytotoxicity
assays indicate that several analogs have a significant effect on tumor cells,
reducing their viability to a variable degree. In cervical cancer, it can be
observed that analogs Ala2-KP10, Ala3-KP10, and Ala4-KP10
showed a higher cytotoxic response, which leads to an essential result in
cancer research. Evidence indicates that Kisspeptin can increase cell
proliferation and invasion of cervical cancer cells31. In addition, Kisspeptin and its receptor are
overexpressed in cervical cancer cells31. This suggests that analogs Ala2-KP10, Ala3-KP10,
and Ala4-KP10 may behave antagonistically at the Kiss1R receptor
expressed on cervical cancer cells. In the docking analyses, analogs Ala3-KP10
and Ala8-KP10 show a higher generation of hydrogen bonds than native Kisspeptin.
Figure 4 and the following table illustrate the interactions observed between
the respective analogs and the KissR receptor for the best model.

Table 5. Chemical interactions between
kisspeptin analogs and the Kiss1R receptor in the best model
A relevant direct Ala3-Trp12
interaction is observed in Ala3-KP10, which allows a possible
formation of hydrogen bonds. Tryptophan molecules contain functional groups
such as indole and amino groups, which can form hydrogen bonds with the
carboxyl group of Alanine. This interaction can stabilize the three-dimensional
structure of the proteins in which they are found. In addition, Alanine and
tryptophan can interact through dispersion forces, which are weak interactions
between non-polar atoms. These forces can contribute to the stability of the
protein structure. It is important to note that the interaction between Alanine
and tryptophan can vary depending on their position in the amino acid sequence
of a protein and the environment in which they are found. The unique properties
of each amino acid can influence how they interact.
In Ala8-KP10, when it
changed a leucine by Alanine, it is observed that the glycine in position 7 leads
in the non-covalent interactions with the receptor. By changing Leu8
to Ala8, two relevant interactions between Gly7 with Arg187
and Tyr189 occur. The new peptide conformation allows a better
interaction between these amino acids. As for molecular docking analysis,
several significant interactions between kisspeptin analogs and cell
proliferation-associated proteins have been identified. In particular, it has
been found that the analogs with the highest affinity for these proteins also
have the most significant cytotoxic effect.
Other interesting interactions
observed with KP10 and analogs and Kiss1R: Interaction between Asn2 of KP10
and Arg197: This interaction involves the formation of a hydrogen bond
between the amino group of asparagine (Asn2) in the KP10 peptide and the
carboxyl group of arginine (Arg197). This interaction may be necessary for
stabilizing the peptide structure and binding to the Kiss1R receptor. Interaction
between Trp3 of Ala8-KP10 and Trp12: Here, the tryptophan (Trp3)
of KP10 interacts with glutamic acid (Trp12) via hydrogen bonds and possible
hydrophobic interactions. These interactions may be crucial for recognition and
binding to the Kiss1R receptor. Interestingly, native Kisspeptin also contains
a tryptophan at position 3, suggesting a conservation of this interaction in
KP10 analogs. Interaction between Ser5 of Ala4-KP10 and Glu200:
The serine (Ser5) of Ala4-KP10 forms hydrogen bonds with glutamic
acid (Glu200). These interactions may be important in stabilizing the peptide
conformation and promoting receptor binding. In native Kisspeptin, the serine
is also found at position 5, indicating the conservation of this interaction in
KP10 analogs. Interaction between Arg9 of KP10 and Ser6: In this case,
the arginine residue (Arg9) of KP10 interacts with the adjacent serine (Ser6).
This interaction may play a role in stabilizing the peptide structure and
binding to the Kiss1R receptor. This interaction in KP10 analogs suggests a
conservation of the interaction between Arg9 and nearby residues in native Kisspeptin.
These differences in
ligand-receptor chemical interactions seen by molecular docking simulations do
not allow us to deduce the behavior observed in cytotoxicity assays. High
cytotoxicity can be observed in cervical cancer cells, medium cytotoxicity in
prostate cancer cells, and none in healthy cells (Figure 3). We allude to these
different responses between cervical and prostate cancer to the different
cellular membranes each of these cells has; we believe that each cell's lipid
composition and membrane components make the receptor act differently in each
type of cancer studied.
Discussion surrounding these results should focus on how these findings
can be used to further the development of kisspeptin analogs as an anticancer
therapy. There is a need to examine further the molecular interactions
identified and to determine which specific features of the analogs result in
the observed cytotoxicity. It is also essential to consider the possibility
that these analogs may affect normal cells in the body and how this might be
mitigated in clinical use. In addition, it is essential to perform studies on
the lipid composition of the membranes of different cells in different types of
cancer. It may be relevant to observe the different responses that the
kisspeptin system can provide.

Figure
3. Comparison of analogs Ala3-KP10 and Ala4-KP10 concerning
cytotoxicity between healthy cells (HEK293) and cervical (HeLa) and prostate
(PC3) cancer cells.

Figure
4. Interesting interactions between KissR receptor and A) KP10, B) Ala3-KP10
and C) Ala4-KP10.
CONCLUSIONS
This study investigated
the interactions between kisspeptin10 analogs and the Kiss1R receptor and the
cytotoxic effects on cervical and prostate cancer cells. Our results
demonstrate that kisspeptin10 analogs can interact successfully with the Kiss1R
receptor, suggesting their potential as therapeutic tools in treating these
cancers. Furthermore, cytotoxicity assays revealed that kisspeptin10 analogs
exhibited significant cytotoxic activity against cervical and prostate cancer
cells. These findings further support the therapeutic potential of kisspeptin10
analogs and suggest their possible application in targeted cancer therapy. Importantly,
further studies are required to fully understand these interactions' underlying
mechanisms and evaluate the efficacy and safety of kisspeptin10 analogs in in vivo models and clinical trials.
Nevertheless, our promising results suggest that kisspeptin10 analogs represent
an exciting direction in searching for new cervical cancer therapies.
In conclusion, this
study provides initial evidence of the interactions between kisspeptin10
analogs and the Kiss1R receptor and their cytotoxic activity in cervical and
prostate cancer cells. These findings support the need for future research to
fully explore the therapeutic potential of kisspeptin10 analogs in treating
these cancers, providing renewed hope for improving patients' quality of life.
Author
Contributions:
A short paragraph specifying their individual contributions must be provided
for research articles with several authors. The following statements should be
used “Conceptualization, D.Y.R.S.; methodology, D.J.T.S.; software, P.R.V.;
investigation, D.Y.R.S.; writing—original draft preparation, D.Y.R.S.;
writing—review and editing, D.Y.R.S, P.R.V.; project administration, D.Y.R.S.;
funding acquisition, D.Y.R.S.
Funding: This research was
funded by MINCIENCIAS, Government of Colombia. Grant 808-2017.
Conflicts
of Interest:
The authors declare no conflict of interest.
REFERENCES
1 Lee, D. K. et al. Discovery
of a receptor related to the galanin receptors. FEBS Lett 446, 103-107,
doi:10.1016/s0014-5793(99)00009-5 (1999).
2 Kotani,
M. et al. The metastasis suppressor
gene KiSS-1 encodes kisspeptins, the natural ligands of the orphan G
protein-coupled receptor GPR54. J Biol
Chem 276, 34631-34636,
doi:10.1074/jbc.M104847200 (2001).
3 Muir,
A. I. et al. AXOR12, a novel human G
protein-coupled receptor, activated by the peptide KiSS-1. J Biol Chem 276,
28969-28975, doi:10.1074/jbc.M102743200 (2001).
4 Ohtaki,
T. et al. Metastasis suppressor gene
KiSS-1 encodes peptide ligand of a G-protein-coupled receptor. Nature 411, 613-617, doi:10.1038/35079135 (2001).
5 Dhillo,
W. S. et al. Kisspeptin-54 stimulates
the hypothalamic-pituitary gonadal axis in human males. J Clin Endocrinol Metab 90,
6609-6615, doi:10.1210/jc.2005-1468 (2005).
6 Dungan,
H. M. et al. The role of
kisspeptin-GPR54 signaling in the tonic regulation and surge release of
gonadotropin-releasing hormone/luteinizing hormone. J Neurosci 27,
12088-12095, doi:10.1523/JNEUROSCI.2748-07.2007 (2007).
7 Lapatto,
R. et al. Kiss1-/- mice exhibit more
variable hypogonadism than Gpr54-/- mice. Endocrinology
148, 4927-4936,
doi:10.1210/en.2007-0078 (2007).
8 Seminara,
S. B. et al. The GPR54 gene as a
regulator of puberty. N Engl J Med 349, 1614-1627,
doi:10.1056/NEJMoa035322 (2003).
9 Lee,
J. H. & Welch, D. R. Suppression of metastasis in human breast carcinoma
MDA-MB-435 cells after transfection with the metastasis suppressor gene,
KiSS-1. Cancer Res 57, 2384-2387 (1997).
10 Martin,
T. A., Watkins, G. & Jiang, W. G. KiSS-1 expression in human breast cancer.
Clin Exp Metastasis 22, 503-511,
doi:10.1007/s10585-005-4180-0 (2005).
11 McNally,
L. R. et al. KISS1 over-expression
suppresses metastasis of pancreatic adenocarcinoma in a xenograft mouse model. Clin Exp Metastasis 27, 591-600, doi:10.1007/s10585-010-9349-5 (2010).
12 Nagai,
K. et al. Prognostic value of
metastin expression in human pancreatic cancer. J Exp Clin Cancer Res 28,
9, doi:10.1186/1756-9966-28-9 (2009).
13 Wang,
C. H., Qiao, C., Wang, R. C. & Zhou, W. P. KiSS‑1‑mediated suppression of
the invasive ability of human pancreatic carcinoma cells is not dependent on
the level of KiSS‑1 receptor GPR54. Mol
Med Rep 13, 123-129,
doi:10.3892/mmr.2015.4535 (2016).
14 Jayasena,
C. N. et al. Plasma kisspeptin: a
potential biomarker of tumor metastasis in patients with ovarian carcinoma. Clin Chem 58, 1061-1063, doi:10.1373/clinchem.2011.177667 (2012).
15 Kang,
H. S. et al. GPR54 is a target for
suppression of metastasis in endometrial cancer. Mol Cancer Ther 10,
580-590, doi:10.1158/1535-7163.MCT-10-0763 (2011).
16 Makri,
A. et al. KISS1/KISS1R expression in
eutopic and ectopic endometrium of women suffering from endometriosis. In Vivo 26, 119-127 (2012).
17 Ergen,
A. et al. Plasma Kisspeptin-54 levels
in gastric cancer patients. Int J Surg
10, 551-554,
doi:10.1016/j.ijsu.2012.08.014 (2012).
18 Kostakis,
I. D. et al. KISS1 and KISS1R
expression in gastric cancer. J BUON 23, 79-84 (2018).
19 Li,
N., Wang, H. X., Zhang, J., Ye, Y. P. & He, G. Y. KISS-1 inhibits the
proliferation and invasion of gastric carcinoma cells. World J Gastroenterol 18,
1827-1833, doi:10.3748/wjg.v18.i15.1827 (2012).
20 Cho,
S. G. et al. Kisspeptin-10, a
KISS1-derived decapeptide, inhibits tumor angiogenesis by suppressing
Sp1-mediated VEGF expression and FAK/Rho GTPase activation. Cancer Res 69, 7062-7070, doi:10.1158/0008-5472.CAN-09-0476 (2009).
21 Curtis,
A. E. et al. Kisspeptin is released
from human prostate cancer cell lines but plasma kisspeptin is not elevated in
patients with prostate cancer. Oncol Rep
23, 1729-1734,
doi:10.3892/or_00000818 (2010).
22 Wang,
H. et al. Clinical and biological
significance of KISS1 expression in prostate cancer. Am J Pathol 180,
1170-1178, doi:10.1016/j.ajpath.2011.11.020 (2012).
23 Mirdita,
M. et al. ColabFold: making protein
folding accessible to all. Nat Methods
19, 679-682,
doi:10.1038/s41592-022-01488-1 (2022).
24 Wiederstein,
M. & Sippl, M. J. ProSA-web: interactive web service for the recognition of
errors in three-dimensional structures of proteins. Nucleic Acids Res 35,
W407-410, doi:10.1093/nar/gkm290 (2007).
25 Lamiable,
A. et al. PEP-FOLD3: faster de novo
structure prediction for linear peptides in solution and in complex. Nucleic Acids Res 44, W449-454, doi:10.1093/nar/gkw329 (2016).
26 Schrödinger,
L., & DeLano, W., . PyMOL, <www.pymol.org/pymol>
(2020).
27 Bloodworth,
N., Barbaro, N. R., Moretti, R., Harrison, D. G. & Meiler, J. Rosetta
FlexPepDock to predict peptide-MHC binding: An approach for non-canonical amino
acids. PLoS One 17, e0275759, doi:10.1371/journal.pone.0275759 (2022).
28 PRODIGY: a web server for predicting the
binding affinity of protein-protein complexes, <https://wenmr.science.uu.nl/prodigy/>
(2020).
29 Systemes,
D. BIOVIA Discovery Studio v21.1.0.20298,
, <https://www.3ds.com/es/productos-y-servicios/biovia/>
(2020).
30 Merrifield,
R. B. Solid Phase Peptide Synthesis .1. Synthesis of a Tetrapeptide. Journal of the American Chemical Society
85, 2149-&, doi:https://doi.org/10.1021/ja00897a025
(1963).
31 Taniguchi-Ponciano, K. et al. The
KISS1 gene overexpression as a potential molecular marker for cervical cancer
cells. Cancer Biomark 22, 709-719, doi:10.3233/CBM-181215
(2018).
Received: 25 June 2023/ Accepted: 26 August 2023 /
Published:15 September 2023
Citation: Rodríguez
Sarmiento D Y, Toloza Sandoval D J, Rondón-Villarreal P. Structural analysis and cytotoxic evaluation of
kisspeptin10 and analogs in types of cancer. Revis Bionatura
2023;8 (3) 61. http://dx.doi.org/10.21931/RB/2023.08.03.61