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Melanocortin & Copper Peptides

MT2

Also written Melanotan II · Melanotan 2 · MT-II

MT2 is a synthetic cyclic heptapeptide. Supplied as a lyophilised powder in a sealed vial for laboratory research. Available in a 10 mg presentation.

In stock
10 mg vial£30.00

£3.00 per mg

≥99% purity (HPLC) · Independent third-party testing by PeptideVerify · COA Library

Order before 3pm for same-day dispatch.

Cut-off 3pm, Mon–Sat

Free next-day tracked delivery on every order · Royal Mail Tracked 24

10 mg · £30.00 · £3.00/mg

At a glance

Research area
Melanocortin & Copper Peptides · Explore the research area
Presentations
10 mg
Form
Lyophilised powder in a sealed vial
Purity
≥99% (HPLC)
CAS number
121062-08-6
Molecular formula
C50H69N15O9
Molecular weight
1024.18 g/mol
Residues
7
Monoisotopic mass
1023.5403 Da
Dispatch
Order by 3pm Mon–Sat for same-day dispatch

About MT2

MT2 is a synthetic cyclic heptapeptide, Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2. A lactam bond between the side chains of aspartic acid and lysine closes a ring of six residues, leaving N-acetyl-norleucine outside the ring at the N-terminus; norleucine is a non-proteinogenic isomer of leucine with an unbranched side chain. The ring holds one D-configured residue, D-phenylalanine, and the C-terminal lysine ends in an amide.

The catalogue lists CAS number 121062-08-6, the molecular formula C50H69N15O9 and a molecular weight of 1024.18 g/mol. Mass spectrometry confirms identity and cyclisation together, since the cyclic form is 18 Da lighter than its open-chain precursor, and tryptophan gives the peptide a useful ultraviolet absorbance at 280 nm for HPLC. Each presentation is supplied as a lyophilised powder in a sealed vial.

Further reading

MT2 structure and analytical profile

Numbered from the N-terminus, the seven residues are Nle1, Asp2, His3, D-Phe4, Arg5, Trp6 and Lys7, written compactly as Ac-[Nle]DHfRWK-NH2, where the lower-case f marks the D-residue. The ring is closed by an amide bond between the side-chain carboxyl of Asp2 and the side-chain amine of Lys7, so it spans six residues, Asp2 to Lys7, and Nle1 sits outside it.

That side-chain lactam is a second amide bond in the molecule, separate from the backbone. Forming it eliminates one molecule of water, which is why the cyclic peptide is 18 Da lighter than the same chain left open, and why mass spectrometry confirms the ring and the sequence in a single measurement.

Trp6, D-Phe4 and His3 give the ring three aromatic side chains and Arg5 its one guanidine; all four sit inside the lactam ring, with norleucine the only residue outside it.

Both ends are capped. The N-terminal norleucine carries an acetyl group, so there is no free amine at the start of the chain, and the C-terminal lysine ends in an amide, so there is no free carboxylic acid. With the side chains of Asp2 and Lys7 joined in the lactam, the remaining ionisable groups are the arginine guanidine and the histidine imidazole.

The calculated net charge near pH 7 is about +1.2, set mainly by Arg5. Norleucine, an unbranched isomer of leucine, adds a short hydrocarbon side chain to the N-terminal cap, and Trp6 is the chain's one strong ultraviolet chromophore.

The monoisotopic mass is 1023.5403 Da, so the [M+H]+ ion is expected at m/z 1024.5475 and the [M+2H]2+ ion at m/z 512.7774. An open-chain form would sit 18 Da higher, and the free-acid C-terminus would sit about 0.98 Da higher, so the measured mass checks ring closure and the amide end together.

Tandem mass spectrometry needs two backbone cleavages to free a fragment from inside the ring, so the cyclic heptapeptide gives a fragment pattern unlike a linear chain of the same residues, which confirms that the lactam is closed.

Reversed-phase HPLC with detection at 280 nm, where Trp6 absorbs, or around 214 nm gives purity as the main peak's share of total peak area. The material is a white to off-white lyophilised solid in a sealed vial. The sealed vial is stored at 2–8 °C short term, or at −20 °C and below for long-term storage, protected from light and away from repeated freeze-thaw cycles.

Buying MT2 in the UK

Order MT2 directly from British Peptide Labs, a UK-registered company, as a sealed vial in 10 mg presentation, from £30. Every size is listed below with its vial price and its price per mg, so the presentations compare at a glance.

MT2 price (UK)
PresentationPrice£/mg
MT2 10 mg£30.00£3.00

Choose a presentation in the buy box, add it to your basket and check out. Orders placed before 3pm Mon–Sat are packed the same working day and handed to Royal Mail Tracked 24, and your tracking number is emailed as soon as the parcel leaves us. Larger orders are welcome: add as many vials as your laboratory needs in a single basket.

For what other UK suppliers charge, see our UK price per mg data, updated every month.

Product information

Synonym
Melanotan II, Melanotan 2, MT-II
CAS number
121062-08-6
Molecular formula
C50H69N15O9
Molecular weight
1024.18 g/mol
Sequence
Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2
Appearance
White to off-white lyophilised powder
Purity
≥99% (HPLC)
Net content
10 mg per vial
Storage (sealed vial)
Store at 2–8 °C short term, or at −20 °C and below for long-term storage. Protect from light and avoid repeated freeze-thaw cycles
Residues
7
One-letter sequence
Ac-[Nle]DHfRWK-NH2
Monoisotopic mass
1023.5403 Da
Expected [M+H]+
m/z 1024.5475
Net charge near pH 7
+1.2
Research use
For laboratory research use only. Not for human or veterinary use.

MT2 is a synthetic cyclic heptapeptide. Supplied as a lyophilised powder in a sealed vial for laboratory research. Available in a 10 mg presentation. Store the sealed vial at 2–8 °C for short-term storage, or at −20 °C and below for long term. Protect from light and avoid repeated freeze-thaw cycles. For research use only. Not for human or veterinary use. Sold strictly for in-vitro laboratory research; not for diagnosis or treatment.

Packing
Each sealed vial travels in protective packing.
Dispatch
Orders placed before 3pm Mon–Sat leave the same day.
Delivery
Next-day tracked delivery with Royal Mail Tracked 24.
Tracking
Your tracking number is emailed as soon as the order is dispatched.
Delivery cost
Delivery is free on every order.
Shipping details

Questions about MT2

MT2 is a synthetic cyclic heptapeptide. It is supplied in a sealed vial as a white to off-white lyophilised powder, in a 10 mg presentation.

Read the Learn article

Yes. Melanotan II, also written Melanotan 2 or MT-II, names the same molecule as MT2: the cyclic heptapeptide Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, CAS 121062-08-6, with the molecular formula C50H69N15O9 and a molecular weight of 1024.18 g/mol.

Yes. A lactam bond between the side chains of Asp2 and Lys7 closes a six-residue ring, with N-acetyl-norleucine outside it at the N-terminus. The full structure is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2. The ring holds His3, D-Phe4, Arg5 and Trp6 between the two bridged residues.

1024.18 g/mol for the formula C50H69N15O9. The monoisotopic mass is 1023.5403 Da, so the [M+H]+ ion is expected at m/z 1024.5475 and the [M+2H]2+ ion at m/z 512.7774.

Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2 in three-letter code, or Ac-[Nle]DHfRWK-NH2 in compact one-letter form, where the lower-case f marks D-phenylalanine and the square brackets hold norleucine, which has no one-letter code.

Norleucine is 2-aminohexanoic acid, an isomer of leucine with a straight four-carbon side chain instead of a branched one. It is not one of the twenty coded amino acids, and in MT2 it carries the N-terminal acetyl group.

121062-08-6, with the molecular formula C50H69N15O9 and a molecular weight of 1024.18 g/mol. The same values appear in the specifications on this page. It identifies the amide-terminated cyclic heptapeptide described on this page.

In an amide. The C-terminal lysine is amidated, -NH2, and the N-terminus is acetylated, so neither end carries a free charge. The free-acid form would weigh about 0.98 Da more.

Because forming the lactam bond between Asp2 and Lys7 eliminates one molecule of water, 18.01 Da. Mass spectrometry therefore confirms cyclisation and sequence together.

Order MT2 directly from British Peptide Labs, a UK-registered company. It is supplied in a sealed 10 mg vial at £30.00 (£3.00 per mg). The 10 mg vial is in stock. Every vial is ≥99% purity (HPLC), with independent third-party testing by PeptideVerify. Orders placed before 3pm Mon–Sat leave the same day by Royal Mail Tracked 24 for next-day tracked delivery.

MT2 comes in one sealed vial: 10 mg at £30.00 (£3.00 per mg). Delivery is free on every order.

MT2 is catalogued in the Melanocortin & Copper Peptides research area, where compounds are grouped by molecular class. The research area page lists each of them with its identifiers.

Melanocortin & Copper Peptides research area

MT2 has independent third-party testing by PeptideVerify: reversed-phase HPLC measures purity, at ≥99% (HPLC), and LC-MS confirms identity against the expected mass.

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