Cosmic Peptides research library

Tesamorelin

The full 44-residue growth hormone–releasing hormone sequence as its C-terminal amide, with a trans-3-hexenoyl group on the N-terminus.

Last reviewed · Editorial policy

The full 44-residue growth hormone–releasing hormone sequence as its C-terminal amide, with a trans-3-hexenoyl group on the N-terminus. Every value on this page is calculated from the structure shown, by the method and constants in the sources below; measured values for a particular lot are on its certificate of analysis.

Structure

Three-letter code: Hexenoyl-Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg-Gln-Gln-Gly-Glu-Ser-Asn-Gln-Glu-Arg-Gly-Ala-Arg-Ala-Arg-Leu-NH2

One-letter code: YADAIFTNSY RKVLGQLSAR KLLQDIMSRQ QGESNQERGA RARL

  • 44 residues
  • N-terminus: N-(trans-3-hexenoyl)
  • C-terminus: amide

Calculated properties

Calculated from the structure
PropertyValue
Molecular formulaC221H366N72O67S
CAS Registry Number218949-48-5
Average molecular weight5,135.86 g/mol
Monoisotopic mass5,132.7166 Da
Net charge at pH 74.0
Isoelectric point11.43
Molar absorption coefficient, 280 nm2,980 M−1 cm−1
Hydropathy (GRAVY)-0.80
Net charge across the pH range
pH 2pH 4pH 6pH 7pH 8pH 10pH 12
8.06.04.04.04.02.8-1.3

Composition: Arg 6, Ala 5, Gln 5, Leu 5, Ser 4, Gly 3, Asn 2, Asp 2, Glu 2, Ile 2, Lys 2, Tyr 2, Met 1, Phe 1, Thr 1, Val 1.

Expected mass spectrometry ions

The protonated ions expected in positive-mode electrospray, from the monoisotopic mass, and the common sodium and potassium adducts. MALDI spectra show mainly [M+H]+.

Expected ions (monoisotopic)
Ionm/z
[M+H]+5,133.7239
[M+2H]2+2,567.3656
[M+3H]3+1,711.9128
[M+4H]4+1,284.1864
[M+5H]5+1,027.5506
[M+6H]6+856.4600
[M+Na]+5,155.7059
[M+K]+5,171.6798

Isotope pattern

Natural carbon-13, nitrogen-15, oxygen-18, sulfur-34 and deuterium spread each ion over a cluster of peaks about 1 Da apart (1/z on the m/z scale). For a molecule this size the monoisotopic peak is not the tallest: the most abundant is M+2. A spectrum read at its tallest peak, or a deconvoluted mass from it, sits about 2.01 Da above the monoisotopic mass.

050100MM+1M+2M+3M+4M+5M+6M+7M+8M+9M+10
Calculated isotope pattern of the neutral molecule, from IUPAC isotopic abundances.
Isotope peaks (relative abundance, most abundant = 100)
PeakAbundanceNeutral mass[M+H]+[M+2H]2+[M+3H]3+[M+4H]4+[M+5H]5+[M+6H]6+
M (monoisotopic)25.75,132.71665,133.72392,567.36561,711.91281,284.18641,027.5506856.4600
M+170.15,133.71945,134.72672,567.86701,712.24711,284.43711,027.7512856.6272
M+2100.05,134.72215,135.72932,568.36831,712.58131,284.68781,027.9517856.7943
M+398.95,135.72465,136.73182,568.86961,712.91551,284.93841,028.1522856.9614
M+475.85,136.72705,137.73422,569.37081,713.24961,285.18901,028.3527857.1284
M+548.05,137.72935,138.73662,569.87191,713.58371,285.43961,028.5531857.2955
M+626.05,138.73165,139.73892,570.37311,713.91781,285.69021,028.7536857.4625
M+712.45,139.73395,140.74122,570.87421,714.25191,285.94071,028.9541857.6296
M+85.35,140.73615,141.74342,571.37531,714.58601,286.19131,029.1545857.7966
M+92.05,141.73845,142.74562,571.87651,714.92011,286.44191,029.3549857.9637
M+100.75,142.74065,143.74782,572.37761,715.25411,286.69241,029.5554858.1307

Fragment ions (MS/MS)

Collision-induced fragmentation breaks peptide bonds along the backbone. Fragments that keep the N-terminus are b ions; those that keep the C-terminus are y ions. Reading the ladder confirms the sequence residue by residue. Singly charged monoisotopic values, with doubly charged values beside them. The b ion containing every residue is rarely seen and the y ion containing every residue is the precursor itself, so neither is listed.

b and y ions
b#b+b2+Residuey+y2+y#
1260.1281130.5677Tyr——44
2331.1652166.0863Ala4,874.60312,437.805243
3446.1922223.5997Asp4,803.56602,402.286642
4517.2293259.1183Ala4,688.53902,344.773141
5630.3134315.6603Ile4,617.50192,309.254640
6777.3818389.1945Phe4,504.41782,252.712639
7878.4294439.7184Thr4,357.34942,179.178438
8992.4724496.7398Asn4,256.30172,128.654537
91,079.5044540.2558Ser4,142.25882,071.633036
101,242.5677621.7875Tyr4,055.22682,028.117035
111,398.6688699.8381Arg3,892.16351,946.585434
121,526.7638763.8855Lys3,736.06241,868.534833
131,625.8322813.4197Val3,607.96741,804.487332
141,738.9163869.9618Leu3,508.89901,754.953131
151,795.9377898.4725Gly3,395.81491,698.411130
161,923.9963962.5018Gln3,338.79341,669.900429
172,037.08041,019.0438Leu3,210.73491,605.871128
182,124.11241,062.5598Ser3,097.65081,549.329027
192,195.14951,098.0784Ala3,010.61881,505.813026
202,351.25061,176.1290Arg2,939.58171,470.294525
212,479.34561,240.1764Lys2,783.48061,392.243924
222,592.42971,296.7185Leu2,655.38561,328.196423
232,705.51371,353.2605Leu2,542.30151,271.654422
242,833.57231,417.2898Gln2,429.21751,215.112421
252,948.59931,474.8033Asp2,301.15891,151.083120
263,061.68331,531.3453Ile2,186.13191,093.569619
273,192.72381,596.8655Met2,073.04791,037.027618
283,279.75581,640.3816Ser1,942.0074971.507317
293,435.85691,718.4321Arg1,854.9754927.991316
303,563.91551,782.4614Gln1,698.8743849.940815
313,691.97411,846.4907Gln1,570.8157785.911514
323,748.99561,875.0014Gly1,442.7571721.882213
333,878.03821,939.5227Glu1,385.7356693.371512
343,965.07021,983.0387Ser1,256.6930628.850211
354,079.11312,040.0602Asn1,169.6610585.334110
364,207.17172,104.0895Gln1,055.6181528.31279
374,336.21432,168.6108Glu927.5595464.28348
384,492.31542,246.6613Arg798.5169399.76217
394,549.33692,275.1721Gly642.4158321.71156
404,620.37402,310.6906Ala585.3943293.20085
414,776.47512,388.7412Arg514.3572257.68234
424,847.51222,424.2597Ala358.2561179.63173
435,003.61332,502.3103Arg287.2190144.11312
44——Leu131.117966.06261

Immonium ions (low-mass markers of the residues present): Gly 30.0338, Ala 44.0495, Ser 60.0444, Val 72.0808, Thr 74.0600, Ile 86.0964, Leu 86.0964, Asn 87.0553, Asp 88.0393, Gln 101.0709, Lys 101.1073, Glu 102.0550, Met 104.0528, Phe 120.0808, Arg 129.1135, Tyr 136.0757.

What to watch for analytically

Variants this sequence can give, from its chemistry. They are what an HPLC or mass spectrometry result for this peptide is read against; none is a statement about a particular lot. Where synthesis variants come from is explained in How synthetic peptides are made.

Sequence-specific variants
VariantMass changeWhy
Methionine oxidation+15.995 Da per oxidized residueMethionine at position 27 can oxidize to the sulfoxide, which usually elutes slightly earlier in reversed-phase HPLC.
Asparagine deamidation+0.984 DaAsparagine at positions 8 and 35 can deamidate to aspartic or isoaspartic acid through a succinimide intermediate. Moisture, higher pH and warmth speed it up.
Glutamine deamidation+0.984 DaGlutamine at positions 16, 24, 30, 31 and 36 can also deamidate, much more slowly than asparagine.
C-terminal amidefree-acid variant +0.984 DaThe C-terminus is an amide. The corresponding free acid, from synthesis or hydrolysis, differs by +0.984 Da, close to the isotope spacing, so it needs a resolved spectrum to tell apart.
Synthesis-related variantse.g. +252.082 Da (Pbf), minus a residue (deletion)As for any synthetic peptide, deletion sequences and incompletely deprotected forms can occur; on arginine, a residual Pbf protecting group adds 252.082 Da.

Sources & Further Reading

  1. Prohaska T, Irrgeher J, Benefield J, Böhlke JK, Chesson LA, Coplen TB, et al. Standard atomic weights of the elements 2021 (IUPAC Technical Report). Pure and Applied Chemistry 2022;94(5):573–600. doi:10.1515/pac-2019-0603
  2. Wang M, Huang WJ, Kondev FG, Audi G, Naimi S. The AME 2020 atomic mass evaluation (II). Tables, graphs and references. Chinese Physics C 2021;45(3):030003. doi:10.1088/1674-1137/abddaf
  3. Rice P, Longden I, Bleasby A. EMBOSS: the European Molecular Biology Open Software Suite. Trends in Genetics 2000;16(6):276–277. doi:10.1016/S0168-9525(00)02024-2
  4. Pace CN, Vajdos F, Fee L, Grimsley G, Gray T. How to measure and predict the molar absorption coefficient of a protein. Protein Science 1995;4(11):2411–2423. doi:10.1002/pro.5560041120
  5. Kyte J, Doolittle RF. A simple method for displaying the hydropathic character of a protein. Journal of Molecular Biology 1982;157(1):105–132. doi:10.1016/0022-2836(82)90515-0
  6. Meija J, Coplen TB, Berglund M, Brand WA, De Bièvre P, Gröning M, et al. Isotopic compositions of the elements 2013 (IUPAC Technical Report). Pure and Applied Chemistry 2016;88(3):293–306. doi:10.1515/pac-2015-0503
  7. Roepstorff P, Fohlman J. Letter to the editors: proposal for a common nomenclature for sequence ions in mass spectra of peptides. Biomedical Mass Spectrometry 1984;11(11):601. doi:10.1002/bms.1200111109
  8. Biemann K. Contributions of mass spectrometry to peptide and protein structure. Biomedical and Environmental Mass Spectrometry 1988;16(1–12):99–111. doi:10.1002/bms.1200160119
  9. Geiger T, Clarke S. Deamidation, isomerization, and racemization at asparaginyl and aspartyl residues in peptides. Succinimide-linked reactions that contribute to protein degradation. Journal of Biological Chemistry 1987;262(2):785–794. doi:10.1016/S0021-9258(19)75855-4
  10. Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharmaceutical Research 2010;27(4):544–575. doi:10.1007/s11095-009-0045-6
  11. D'Hondt M, Bracke N, Taevernier L, Gevaert B, Verbeke F, Wynendaele E, et al. Related impurities in peptide medicines. Journal of Pharmaceutical and Biomedical Analysis 2014;101:2–30. doi:10.1016/j.jpba.2014.06.012

See also

Cite this page

Text

Cosmic Peptides. (2026, October 25). Tesamorelin: peptide reference entry. Cosmic Peptides Research Library. Retrieved October 26, 2026, from https://cosmicpeptides.com/research/peptides/tesamorelin

BibTeX

@misc{cosmicpeptides_research_peptides_tesamorelin,
  author       = {{Cosmic Peptides}},
  title        = {Tesamorelin: peptide reference entry},
  howpublished = {Cosmic Peptides Research Library},
  year         = {2026},
  month        = oct,
  url          = {https://cosmicpeptides.com/research/peptides/tesamorelin},
  urldate      = {2026-10-26},
  note         = {Last reviewed 2026-10-25}
}

RIS

TY  - ELEC
AU  - Cosmic Peptides
TI  - Tesamorelin: peptide reference entry
T2  - Cosmic Peptides Research Library
PB  - Cosmic Peptides
PY  - 2026
DA  - 2026/10/25
UR  - https://cosmicpeptides.com/research/peptides/tesamorelin
Y2  - 2026/10/26
LA  - en
ER  -

Cite the date the page was last reviewed, October 25, 2026, as its version. Reference managers such as Zotero can save this page directly.

Changes to this page

  1. Updated Peptide mass match, isotope patterns and fragment ions

    Check the masses from a spectrum or a certificate against a sequence; every reference entry and calculation now shows its isotope pattern and its b- and y-ion ladder.

  2. Published Peptide reference: 24 entries and a property table

    Identity, calculated properties, expected mass spectrometry ions and analytical notes for 24 research peptides, all calculated from the structure, with the full table as CSV and JSON.

Changes of substance are listed here; wording changes are not. Every correction is also on the corrections log.

For in vitro laboratory research only. Not for human or veterinary use. This library describes chemistry, analytical methods and published laboratory research; it gives no guidance on use in people or animals.