Sermorelin

Sermorelin is the amidated 1-29 fragment of growth hormone-releasing hormone, the shortest N-terminal segment of the native 44-residue releasing factor that retains its full activity. It carries CAS 114466-38-5, a molecular weight of about 3,358 g/mol and the formula C149H246N44O42S. Its target, the GHRH receptor, is a seven-transmembrane G protein-coupled receptor related to the secretin and vasoactive intestinal peptide receptors, expressed predominantly in the anterior pituitary gland.

Sermorelin in the research literature

The GHRH receptor was cloned from rat pituitary mRNA; membranes from cells transfected with the corresponding cDNA bound GHRH with high affinity and specificity, and the peptide raised intracellular cAMP in those cells, establishing the signalling mechanism sermorelin engages.

GRF(1-29)-NH2 prepared by enzymatic amidation of a glycine-extended precursor was characterised as equipotent with GRF(1-44)-NH2, showing full potency in a rat pituitary bioassay and full receptor-binding affinity; the same work characterised the substituted analog [Ala15]-GRF(1-29)-NH2, described as superactive in that assay. The 1-29 fragment has also served as the scaffold for longer-acting derivatives: maleimido derivatives of it were conjugated to serum albumin, and the conjugates showed greater in vitro stability against dipeptidylpeptidase-IV while remaining active in a growth hormone secretion assay on cultured rat anterior pituitary cells.