Definition is Sex Peptide: according to ( 7. https://pubmed.ncbi.nlm.nih.gov/1365892/ ; https://link.springer.com/article/10.1007/s00018-003-3052Sex-peptides: seminal peptides of the Drosophila male | SpringerLink ), the sex-peptide, therefore, can be considered as a pheromone, that is synthesized by the male and transferred into the female during copulation.
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” NMR studies of the solution conformation of the sex peptide from Drosophila melanogaster. ” by Moehle, K., Freund, A., Kubli, E., Robinson, J.A.https://www.sciencedirect.com/science/article/pii/S0014579311002067
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- Abstract:
The insect sex peptide (SP) elicits a variety of biological responses upon transfer to the mated female. SP contains 36 amino acids, including a tryptophan-rich N-terminal region, a central region containing five hydroxyproline (Hyp) residues, and a C-terminal region enclosed by a disulfide bridge. The solution structure of SP, studied here using NMR spectroscopy, includes a motif WPWN that adopts a type I β-turn in the N-terminal Trp-rich region. This turn region is connected to the central Hyp-rich region, which adopts extended and/or PPII-like conformations. The C-terminal disulfide-bonded loop populates helical turns or nascent helical structure. Overall, the results reveal a rather flexible peptide that lacks a compact folded structure in solution.
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Seminal fluid proteins and chemistries, known as sex peptide, can alter female behaviour and physiology and can mediate sexual conflict. triggers remarkable post-mating responses in females, including altered fecundity, feeding, immunity and sexual receptivity. These effects can favour the evolutionary interests of males while generating costs in females.
During sexual arousal, the female also releases sex peptides in the vaginal lubricant / fluid and saliva to stimulation the male partner. Some females can release the vaginal fluid with a high level of prostaglandiin E2 and histamine to stimulate the urethra and prostate for instantaneous semen ejaculation (extraction) in few seconds.
Ref:
2. https://royalsociety.org/news/2012/semen-controls-female-genes/
3. https://www.sciencedirect.com/science/article/abs/pii/S0022191015000608
4. https://www.sciencedirect.com/science/article/pii/S0960982212004782
5. https://www.sciencedirect.com/science/article/pii/S0960982212005180
6. https://www.nature.com/articles/s41559-017-0154
7. https://pubmed.ncbi.nlm.nih.gov/1365892/
8. https://www.sciencedirect.com/science/article/pii/S0014579311002067
9. https://www.sciencedirect.com/science/article/pii/B9780128010280000787