Tesamorelin

Tesamorelin is a synthetic 44-residue peptide of molecular formula C₂₂₁H₃₆₆N₇₂O₆₇S, with an average molecular mass of 5135.86 Da and a monoisotopic mass of 5132.7166 Da. Its peptide portion reproduces the 44-residue mature sequence of human somatoliberin, beginning Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr and ending Gly-Ala-Arg-Ala-Arg-Leu; that segment is carried within the 108-residue precursor recorded under UniProt P01286.

Two synthetic modifications separate the molecule from the native sequence. The alpha-amine of Tyr1 is acylated with a trans-3-hexenoyl group, an unsaturated six-carbon acyl unit contributing C₆H₈O to the composition, and the C-terminus is presented as an amide rather than a free acid. Building the formula from the native 44-residue chain and applying both modifications reproduces the deposited composition exactly, which confirms the substitution pattern independently of the sequence assignment.

The single sulfur atom in the molecular formula corresponds to the lone methionine at position 27, and it is the residue that dominates the oxidative impurity profile: conversion to the sulfoxide adds 15.995 Da and is resolved as a distinct early-eluting peak in reversed-phase gradients. Three aromatic residues, Tyr1, Phe6 and Tyr10, give the molecule measurable absorbance near 280 nm alongside the 214 nm amide band. Eight basic residues (Arg11, Lys12, Arg20, Lys21, Arg29, Arg38, Arg41, Arg43) against three acidic ones place the isoelectric point in the basic range and produce a densely charged envelope of multiply protonated ions under electrospray conditions.

The compound is named in ChEMBL and UniProt against a single receptor entry, the growth hormone-releasing hormone receptor (UniProt Q02643). It is distinguished from the unmodified native 44-residue sequence by the hexenoyl cap and the C-terminal amide, and from the 29-residue N-terminal analogues of the same hormone family by length, by a mass difference in excess of 1700 Da, and by the presence of the acyl group, which those shorter sequences lack entirely.

This material is supplied strictly for in-vitro laboratory research. It is not a drug, food or supplement, and is not for human or veterinary use, diagnosis, or consumption.