PHG · REV 2026.10 For laboratory research use only. Not medical or dosing guidance.
Peptide Handling Guide Storage, handling and documentation for research peptides
Document
CS-MOTSC
Type
Compound handling sheet
Revised
Sources checked
Bands
−20 °C−80 °C

MOTS-c Handling Sheet

Also known as Mitochondrial open reading frame of the 12S rRNA type-c

A 16-residue mitochondrial-derived peptide with two methionines, a tryptophan and two tyrosines. It is the most oxidation- and light-sensitive peptide in this collection.

2 min read

Identity

Sequence
MRWQEMGYIFYPRKLR
Formula
C101H152N28O22S2
Molecular weight
2174.6 g/mol (average)
Usual supplied form
Lyophilized powder
Record
PubChem

M oxidation-prone N deamidation-prone D Asp-Gly / Asp-Ser site

Formula and weight are for the free peptide. Salt forms (acetate, TFA) weigh more; use the figure on the lot's COA.

Storage & sensitivity

Lyophilized−20 °C
In solution−80 °C
Oxidation
High
Light
High
Moisture
Moderate
Inferred from structure

Little compound-specific stability data is published. Guidance follows from the sequence and general peptide chemistry.

Bench card

  • Two Met and one Trp make oxidation the main risk; Trp also absorbs UV.
  • Protect from light at every step: amber tubes, opaque boxes, short bench time.
  • Use degassed solvent and an inert-gas overlay; store solutions at −80 °C.
  • Basic and partly hydrophobic: low-binding tubes for dilute solutions.
  • Watch for +16 and +32 Da peaks on mass spectra.

Handling-relevant features

FeatureWhy it matters for handling
Met1, Met6Each can oxidize to the sulfoxide (+16 Da per Met)
Trp3Strong UV absorber and oxidation site; can generate photosensitized damage
Tyr8, Tyr11, Phe10Aromatic UV absorbers
Gln4Slow deamidation site
Arg2, Lys14, Arg13, Arg16Net positive charge; adsorbs to glass at low concentration

What it is

MOTS-c is a 16-amino-acid peptide encoded in the mitochondrial 12S rRNA gene, first reported by Lee and colleagues in 2015.

Stability profile

Of the compounds covered here, MOTS-c carries the most oxidation-prone residues: two methionines and a tryptophan, plus two tyrosines. Tryptophan is also the strongest UV absorber among the amino acids, so light can both damage it directly and generate reactive species that attack the methionines. These risks are well documented for these residues in general, as reviewed by Li, Schöneich and Borchardt and by Kerwin and Remmele.

Storage

Form Recommended Notes
Sealed powder −20 °C Opaque box, desiccant, inert-gas overlay after opening
Solution, same day On ice Amber tube; degassed solvent
Solution, longer −80 °C Single-use aliquots

Analytical notes

Expected average mass is about 2174.6 Da; in electrospray, expect several charge states (for example 3+ near m/z 726). Peaks at +16 and +32 Da indicate oxidation of one or both methionines; tryptophan oxidation products also add oxygen (+16 or +32 Da).

References

  1. Lee C, Zeng J, Drew BG, et al. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metab. 2015;21(3):443–454. DOI
  2. Li S, Schöneich C, Borchardt RT. Chemical instability of protein pharmaceuticals: mechanisms of oxidation and strategies for stabilization. Biotechnol Bioeng. 1995;48(5):490–500. DOI
  3. Kerwin BA, Remmele RL Jr. Protect from light: photodegradation and protein biologics. J Pharm Sci. 2007;96(6):1468–1479. DOI
  4. Stadtman ER. Oxidation of free amino acids and amino acid residues in proteins by radiolysis and by metal-catalyzed reactions. Annu Rev Biochem. 1993;62:797–821. DOI
  5. Kristensen K, Henriksen JR, Andresen TL. Adsorption of cationic peptides to solid surfaces of glass and plastic. PLoS One. 2015;10(5):e0122419. DOI

This sheet covers laboratory storage and handling of research material only. It does not describe use in humans or animals, and the supplier's datasheet for your lot takes priority.