Difference between revisions of "Hemopressin"

'''Hemopressin''' (Hp) is an alpha [[hemoglobin]] fragment with the sequence PVNFKFLSH, originally identified in extracts of rat brain using an enzyme capture technique.<ref name="pmid12500972">{{cite journal |author=Rioli V, Gozzo FC, Heimann AS, ''et al.'' |title=Novel natural peptide substrates for endopeptidase 24.15, neurolysin, and angiotensin-converting enzyme |journal=J. Biol. Chem. |volume=278 |issue=10 |pages=8547-55 |year=2003 |month=March |pmid=12500972 |doi=10.1074/jbc.M212030200 |url=http://www.jbc.org/content/278/10/8547.long}}</ref> It binds [[cannabinoid receptors]], acting as an [[inverse agonist]] at [[Cannabinoid receptor 1|CB₁]] receptors.<ref name="pmid18077343">{{cite journal |author=Heimann AS, Gomes I, Dale CS, ''et al.'' |title=Hemopressin is an inverse agonist of CB1 cannabinoid receptors |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=104 |issue=51 |pages=20588–93 |year=2007 |month=December |pmid=18077343 |pmc=2154475 |doi=10.1073/pnas.0706980105 |url=http://www.pnas.org/cgi/pmidlookup?view=long&pmid=18077343}}</ref> Longer forms of hemopressin containing 2-3 additional amino acids on the N-terminus have been identified in extracts of mouse brain. These longer hemopressin peptides, named RVD-Hpα and VD-Hpα, bind to CB1 receptors and are [[agonist | agonists]].<ref name="pmid19380512">{{cite journal |author=Gomes I, Grushko JS, Golebiewska U, ''et al.'' |title=Novel endogenous peptide agonists of cannabinoid receptors |journal=FASEB J. |volume=23 |issue=9 |pages=3020-9 |year=2009 |month=September |pmid=19380512 |pmc=2735371 |doi=doi: 10.1096/fj.09-132142  |url=http://www.fasebj.org/cgi/content/short/fj.09-132142v1}}</ref> In addition to the Hp peptides from alpha hemoglobin, a related peptide from beta hemoglobin has been found in mouse brain extracts; this peptide, named VD-Hpβ, is also an agonist at CB1 cannabinoid receptors.<ref name="pmid19380512">{{cite journal |author=Gomes I, Grushko JS, Golebiewska U, ''et al.'' |title=Novel endogenous peptide agonists of cannabinoid receptors |journal=FASEB J. |volume=23 |issue=9 |pages=3020-9 |year=2009 |month=September |pmid=19380512 |pmc=2735371 |doi=doi: 10.1096/fj.09-132142  |url=http://www.fasebj.org/cgi/content/short/fj.09-132142v1}}</ref>

The original Hp peptide reduces sensitivity to painful stimuli in an experimental model of hyperalgesia.<ref name="pmid15652650">{{cite journal |author=Dale CS, Pagano Rde L, Rioli V, ''et al.'' |title=Antinociceptive action of hemopressin in experimental hyperalgesia  |journal=Peptides |volume=26 |issue=3 |pages=431-6 |year=2005 |month=March |pmid=15652650 |doi=10.1016/j.peptides.2004.10.026}}</ref> Hp also reduces food intake in mice.<ref name="pmid20505104">{{cite journal |author=Dodd GT, Mancini G, Lutz B, ''et al.'' |title=The peptide hemopressin acts through CB1 cannabinoid receptors to reduce food intake in rats and mice |journal=J Neurosci. |volume=30 |issue=21 |pages=7369-76 |year=2010 |month=May |pmid=20505104 |doi=10.1523/JNEUROSCI.5455-09.2010 |url=http://www.jneurosci.org/cgi/content/full/30/21/7369}}</ref> However, it remains to be shown if Hp is an endogenous brain peptide. The original purification used boiling acid to extract the peptide from rat brain, and hot acid can specifically cleave D-P bonds. The N-terminally-extended forms RVD-Hpα and VD-Hpα may represent the true endogenous forms.<ref name="pmid20202081">{{cite journal |author=Gelman JS, Sironi J, Castro LM, ''et al.'' |title=Hemopressins and other hemoglobin-derived peptides in mouse brain: comparison between brain, blood, and heart peptidome and regulation in Cpefat/fat mice |journal=J Neurochem. |volume=113 |issue=4 |pages=871-80 |year=2010 |month=May |pmid=20202081 |doi=10.1111/j.1471-4159.2010.06653.x |url=http://www3.interscience.wiley.com/cgi-bin/fulltext/123303445/HTMLSTART}}</ref>

Scientists at the [[University of Manchester]] have discovered that hemopressin could be used as an [[appetite suppressant]] without having the side effects of many other drugs that are used for this purpose. In laboratory test was administrated hemopressin to mice and rats, which reduced significantly food intake. Hemopressin works by affecting the reward centres of the brain which make us feel happy when we eat too much. A further research should be carried out in order to confirm these effects and the safety on people.<ref>http://uk.health.lifestyle.yahoo.net/hemopressin-naturally-supresses-appetite.htm</ref>