Part:BBa_K200014
Opiorphin + EK cleavage site + His Tag
This part codes for the pentapeptide opiorphin. An enterokinase cleavage site and HIS tag have been included for purification purposes.
Usage and Biology
Background
Opiorphin is a pentapeptide (five amino acids long) that was isolated from human saliva in 1996. Opiorphin acts as a pain killing agent. The amino acid sequence for opiorphin is Glutamine-Arginine-Phenylalanine-Serine-Arginine.
A combination of opiorphin's potency and natural presence in saliva have sparked a great deal of interest from a number of philosophical movements most notably from [http://en.wikipedia.org/wiki/David_Pearce_(philosopher) David Pearce] who belongs to the [http://en.wikipedia.org/wiki/Utilitarianism#Negative negative utilitarian] school of ethics.
Mechanism of Action
Preliminary rat studies indicate that opiorphin has a pain killing effect six times stronger than that of morphine. Enkephalins which are natural pain-killing opioids, opiorphin inhibits two enkephalin-catabolizing ectoenzymes, human neutral ecto-endopeptidase, hNEP ([http://www.ebi.ac.uk/thornton-srv/databases/cgi-bin/enzymes/GetPage.pl?ec_number=3.4.24.11 EC 3.4.24.11]), and human ecto-aminopeptidase, hAP-N ([http://www.ebi.ac.uk/thornton-srv/databases/cgi-bin/enzymes/GetPage.pl?ec_number=3.4.11.2 EC 3.4.11.2]). This results in accumulated levels of enkephalins which results in a drop in pain perception 3.
EK Cleavage
See Design Notes for our rationale behind incorporating an EK cleavage sequence and HIS tag onto the N terminus of the opiorphin pentapeptide.
Other Side Effects
Priapism:
A recent study involved genetically engineering retired breeder rats to constitutively express opiorphin. Interestingly, this resulted in the development of a priapic-like condition. It is thought that this condition resulted from the upregulation of the ornithine decarboxylase gene (ODC) by opiorphin 1.
Antidiarrheal:
In an in-vitro bioassay it was shown that opiorphin (in concentarions 10−6 to 10−4 M) caused colonic contraction in a concentration-dependent manner 2. Based on this evidence, opiorphin could have potential as an antidiarrheal agent.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
References
<biblio>
- 1 pmid=19657052
- 2 pmid=19442408
- 3 pmid=17101991
</biblio>
None |