hemorphin-4 hemorphin-4 hemorphin-4 is an endogenous opioid peptide of the hemorphin family which possesses antinociceptive properties and is derived from the β-chain of hemoglobin in the bloodstream. it is a tetrapeptide with the amino acid sequence tyr-pro-trp-thr. hemorphin-4 has affinities for the μ-, δ-, and κ-opioid receptors that are in the same range as the structurally related β-casomorphins, although affinity to the κ-opioid receptor is markedly higher in comparison. it acts as an agonist at these sites. hemorphin-4 also has inhibitory effects on angiotensin-converting enzyme (ace), and as a result, may play a role in the regulation of blood pressure. notably, inhibition of ace also reduces enkephalin catabolism. hemorphin-4 names iupac name (2s,3r)-2-pyrrolidine-2-carbonyl]amino]-3-(1h-indol-3-yl)propanoyl]amino]-3-hydroxybutanoic acid other names l-tyrosyl-l-prolyl-l-tryptophyl-l-threonine identifiers cas number 103930-64-9 3d model (jsmol) interactive image chemspider 16725618 pubchem cid 128444 comptox dashboard (epa) dtxsid20908670 inchi inchi=1s/c29h35n5o7/c1-16(35)25(29(40)41)33-26(37)23(14-18-15-31-22-6-3-2-5-20(18)22)32-27(38)24-7-4-12-34(24)28(39)21(30)13-17-8-10-19(36)11-9-17/h2-3,5-6,8-11,15-16,21,23-25,31,35-36h,4,7,12-14,30h2,1h3,(h,32,38)(h,33,37)(h,40,41)/t16-,21+,23+,24+,25+/m1/s1key: weggkzqijmqcgr-recquvtisa-n smiles c((c(=o)o)nc(=o)(cc1cc2c1cccc2)nc(=o)3cccn3c(=o)(cc4ccc(cc4)o)n)o properties chemical formula c29h35n5o7 molar mass 565.618 g/mol except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). infobox references