MOTS-C 40mg

What is MOTS-C ?

This is the largest MOTS-C vial stocked, four times the mass of the standard 10mg vial. Few UK suppliers sell a 40mg format at all.

The compound is the same in both sizes: sequence MRWQEMGYIFYPRKLR, 2174.5 g/mol, CAS 1627580-64-6. Lee et al. (Cell Metab, 2015) identified it in a short open reading frame within the mitochondrial 12S rRNA and named it MOTS-c. In their work its main target organ appeared to be skeletal muscle, where it inhibited the folate cycle and de novo purine biosynthesis, leading to AMPK activation. The mechanism and the wider mitochondrial-derived peptide literature are covered on the main MOTS-C page. This page covers the 40mg format.

MOTS-C Research Applications

• Metabolic research : MOTS-c prevented age-dependent and high-fat-diet-induced insulin resistance in mice, and diet-induced obesity (Lee et al., 2015).
• Retrograde signalling : under metabolic stress MOTS-c moves into the nucleus and regulates nuclear genes in an AMPK-dependent way, interacting with NRF2 (Kim et al., Cell Metab, 2018).
• Exercise and ageing : exercise induced endogenous MOTS-c in human skeletal muscle and in circulation. The peptide improved physical performance in young, middle-aged and old mice (Reynolds et al., 2021).

Applications match the standard vial, because the compound is the same. Vial size affects study logistics, not endpoints. Higher-throughput designs, dose-response matrices across many plates and long time-course work all consume material faster than a 10mg vial supports, and running one design against one batch removes inter-batch variance. Analytical method development is the other common case, where repeated standard preparations from a single batch stay more consistent.

The 40mg Vial vs the 10mg Vial: Oxidative Exposure Over Working Life

Both vials hold the same peptide, so the comparison is about handling. The sequence carries two methionines, one tryptophan and two tyrosines, all oxidation-labile. A vial with four times the mass is usually used over a longer period and across more stopper punctures. One reconstituted stock therefore picks up more air contact, light and freeze-thaw cycles. The 10mg vial limits that simply by finishing sooner.

The 40mg vial answers with batch continuity, one certificate across four times as much work, and a lower cost per milligram. Aliquoting at the point of reconstitution settles the argument: drawn into single-use volumes, a 40mg vial behaves like a set of small ones.

Research Overview

This page covers the 40mg presentation. The compound is the same 16-residue mitochondrial-derived peptide supplied in the standard vial, sequence MRWQEMGYIFYPRKLR, molecular formula C₁₀₁H₁₅₂N₂₈O₂₂S₂, molecular weight 2174.5 g/mol, CAS 1627580-64-6, and its mechanism, the folate-methionine cycle route to AICAR accumulation and AMPK activation, together with the retrograde mitochondrial-to-nuclear signalling literature, is documented in full on the main MOTS-C page. What is specific to the 40mg vial is handling. Forty milligrams is four times the content of the standard vial in the same glass format, so at a fixed fill volume the reconstituted stock is four times more concentrated. Fill volume is therefore scaled to the target concentration rather than carried over from work done on smaller vials, and the resulting concentration should be recorded against the batch. The more consequential point at this size is oxidative exposure across the vial's working life. The sequence carries two methionine residues, one tryptophan and two tyrosines, all oxidation-labile side chains. A vial holding four times the mass is typically accessed over a longer period and across more stopper penetrations, which increases cumulative headspace air exposure, light exposure and freeze-thaw opportunities on a single reconstituted stock. Aliquoting into single-use volumes immediately after reconstitution therefore matters more here than on a small vial, and is the reason to select this format only where throughput genuinely justifies it. The offsetting advantages are batch continuity under one certificate of analysis and a lower cost per milligram, since vial, stopper, lyophilisation and assay costs are incurred per vial.

Storage and Reconstitution

Store the sealed 40mg vial at -20°C, dry and away from light. Once reconstituted, hold the solution at 2-8°C and freeze single-use aliquots for anything beyond short-term use. On a 40mg vial that is the main defence of the material, because a stock meant to last a long protocol gains oxidative exposure with every re-entry. Minimise headspace air, keep vials and aliquots dark, and label every aliquot with the reconstitution date.

Vials are sold on their own, without bacteriostatic water for mixing or other supplies.

How to reconstitute and handle

To mix MOTS-C powder, let the vial and the bacteriostatic water reach room temperature, then swab both stoppers with alcohol. Run the water slowly down the inside glass wall, not onto the cake, and swirl gently until dissolved. Do not shake. Set the fill volume from your target concentration: 40mg in 4mL gives 10mg/mL, and 40mg in 2mL gives 20mg/mL. We specify no fill volume, since that is a protocol decision. Aliquot into single-use volumes at the point of reconstitution, not later.

• Scale the bacteriostatic water fill volume to your target concentration. A 40mg vial reaches four times the concentration of a 10mg vial at the same fill volume, so a volume carried across from smaller-vial work will not reproduce the same stock.
• Aliquot into single-use volumes immediately after reconstitution and hold them at -20°C. This matters more on a 40mg vial than a small one, because four times the mass in one vial means a longer working life and more accumulated stopper penetrations on a single stock.
• Minimise headspace air exposure and protect from light at every step. The two methionines, tryptophan and two tyrosines in the sequence are oxidation-sensitive side chains, and a vial with a long in-use window accumulates more oxidative exposure than a small one.
• Do not leave dilute solution standing at room temperature. Return aliquots to cold storage promptly after each withdrawal rather than working from a stock left out across a session.
• Introduce the diluent slowly down the inner glass wall, never onto the lyophilised cake, and swirl gently until fully dissolved. Allow the vial to reach room temperature before opening.

For the full method, see the peptide reconstitution guide and the reconstitution calculator.

Research References

• The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance (Cell Metab, 2015)
• The mitochondrial-encoded peptide MOTS-c translocates to the nucleus to regulate nuclear gene expression in response to metabolic stress (Cell Metab, 2018)
• MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis (Nat Commun, 2021)

Published research on MOTS-C is indexed on PubMed. See our full UK buyer's guide for MOTS-C, UK buyer's guide for MOTS-c 40mg and UK buyer's guide for MOTS-c CoA.