MOTS-C Molecular Weight, Sequence & CAS Reference
This comprehensive reference sheet provides verified biochemical data, amino acid sequencing, molecular weight determinations, and CAS registration details for the mitochondrial-derived peptide MOTS-c. Designed exclusively for laboratory researchers and analytical personnel, this technical guide outlines structural metrics, salt counterion impacts, and quality assurance protocols for in vitro and preclinical experimentation.
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This comprehensive reference sheet provides verified biochemical data, amino acid sequencing, molecular weight determinations, and CAS registration details for the mitochondrial-derived peptide MOTS-c. Designed exclusively for laboratory researchers and analytical personnel, this technical guide outlines structural metrics, salt counterion impacts, and quality assurance protocols for in vitro and preclinical experimentation.
Key takeaways
- [MOTS-c](/research-peptides/mots-c) (Mitochondrial Open Reading Frame of the 12S rRNA Type-c) is a 16-amino-acid peptide encoded within the mitochondrial genome.
- The linear amino acid sequence of [MOTS-c](/research-peptides/mots-c) consists of 16 residues arranged in a specific primary structure.
- The molecular formula of free-base [MOTS-c](/research-peptides/mots-c) is C101H152N28O22S2.
- [MOTS-c](/research-peptides/mots-c) is indexed under the Chemical Abstracts Service (CAS) registry number 1627580-64-6.
Primary Technical Specifications of MOTS-c
MOTS-c (Mitochondrial Open Reading Frame of the 12S rRNA Type-c) is a 16-amino-acid peptide encoded within the mitochondrial genome. Unlike nuclear-encoded peptides, MOTS-c originates directly from the 12S ribosomal RNA gene of the mitochondria, representing a distinct class of signaling molecules known as mitochondrial-derived peptides (MDPs). In laboratory settings, understanding its exact structural parameters is vital for concentration calculations, mass spectrometry verification, and assay design.
Researchers evaluating high-purity MOTS-c research peptide must account for its precise molecular mass, sequence order, and counterion content. High-performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS) rely on these exact biochemical parameters to confirm sequence identity, verify post-synthetic purity, and monitor lot-to-lot consistency.
Amino Acid Sequence and Secondary Structure Characteristics
The linear amino acid sequence of MOTS-c consists of 16 residues arranged in a specific primary structure. In standard single-letter code, the sequence is rendered as: MRWQEMGYIFYPRKLR. In three-letter amino acid notation, the primary sequence is expressed as: H-Met-Arg-Trp-Gln-Glu-Met-Gly-Tyr-Ile-Phe-Tyr-Pro-Arg-Lys-Leu-Arg-OH.
The sequence exhibits an amphipathic alpha-helical tendency under specific hydrophobic solvent conditions, containing a balanced mixture of basic, hydrophobic, and uncharged polar residues. The presence of two methionine residues (positions 1 and 6) makes the peptide susceptible to atmospheric oxidation under improper storage conditions, requiring stringent handling protocols in analytical environments. The full sequence breakdown is cataloged across our complete catalog of research peptides for comparative structural analysis.
Molecular Formula, Exact Mass, and Mass Spectrometry Profile
The molecular formula of free-base MOTS-c is C101H152N28O22S2. Based on standard atomic weights, the calculated monoisotopic mass is 2173.11 Da, while the nominal molecular weight is approximately 2174.62 g/mol. In mass spectrometry evaluation, researchers frequently observe multi-charged ionic species due to the multiple basic residues (Arg-2, Arg-13, Lys-14, Arg-16).
During mass spectrometric analysis via ESI-MS or MALDI-TOF, primary observed signals typically correspond to [M+2H]2+, [M+3H]3+, and [M+4H]4+ ion states. Accurate determination of these mass-to-charge ratios (m/z) is essential for validating peptide integrity prior to initiating in vitro or cellular experiments. Researchers cross-referencing spectral data can access sample verification reports via the official PX1 certificate of analysis (COA) portal.
CAS Registry Number and Nomenclature Standards
MOTS-c is indexed under the Chemical Abstracts Service (CAS) registry number 1627580-64-6. Systematic chemical nomenclature lists the compound as Mitochondrial Open Reading Frame of the 12S rRNA Type-c peptide. In literature and scientific databases, it may also be referenced under regional registry aliases or manufacturer internal identifiers, though CAS 1627580-64-6 remains the global standard for chemical identification.
When procuring or indexing reference standards for preclinical studies, laboratory managers should ensure the CAS number corresponds exactly with the sequence MRWQEMGYIFYPRKLR. Discrepancies in CAS registry indexing often point to altered sequences, truncated variants, or non-standard terminal modifications that could alter experimental outcomes.
Salt Forms, Counterion Dynamics, and Net Peptide Content
Solid-phase peptide synthesis (SPPS) of MOTS-c typically yields a trifluoroacetate (TFA) salt form due to the final cleavage process involving trifluoroacetic acid. Because MOTS-c possesses multiple basic side chains (three arginine residues and one lysine residue), a single MOTS-c molecule can bind multiple TFA counterion molecules. Consequently, the total mass of lyophilisate comprises the pure peptide, bound counterions, and residual moisture.
Net peptide content (NPC) for MOTS-c TFA salt usually ranges between 70% and 85%. For example, a vial containing 5.0 mg of gross lyophilized powder at an 80% net peptide content contains 4.0 mg of actual active MOTS-c peptide. Alternatively, acetate salt conversions may be prepared for specialized assays where TFA ions interfere with cellular parameters. Laboratory personnel calculating precise molar concentrations should utilize our specialized peptide reconstitution calculator to adjust for salt factor variations.
Preclinical Mechanisms and Mitochondrial Research Roles
Preclinical studies indicate that MOTS-c acts as a nuclear-translocating signaling peptide involved in metabolic homeostasis and stress responses. In rodent models and isolated cell lines, research demonstrates that MOTS-c translocates to the nucleus under metabolic stress conditions, where it interacts with transcription factors such as NRF2 to regulate adaptive gene expression.
Furthermore, in vitro assays suggest that MOTS-c regulates the folate-purine synthesis pathway, leading to the activation of AMP-activated protein kinase (AMPK). Investigated primarily for its role in mitochondrial function, metabolic regulation, and exercise-capacity research, MOTS-c serves as a fundamental model for understanding retrograde signaling between mitochondria and the nuclear genome in cellular physiology.
Comparative Analysis: MOTS-c vs. Related Mitochondrial Compounds
MOTS-c belongs to a broader class of metabolic and mitochondrial-targeted research compounds. When structuring comparative preclinical studies, researchers frequently evaluate MOTS-c alongside other established signaling molecules within the mitochondrial pathway.
Compared to Humanin—the first discovered mitochondrial-derived peptide containing 24 amino acids—MOTS-c is shorter (16 residues) and exhibits distinct target specificity toward metabolic stress pathways rather than cytoprotective anti-apoptotic pathways. Additionally, synthetic cell-permeable peptides like SS-31 (Elamipretide) target cardiolipin within the inner mitochondrial membrane to optimize electron transport efficiency, whereas MOTS-c operates primarily as a nuclear signaling mediator. Exploring the broader mitochondrial-derived peptides class allows investigators to delineate direct membrane-stabilizing effects from gene-regulatory signaling pathways.
Reconstitution, Handling, and Storage Protocols for Laboratory Use
Lyophilized MOTS-c should be stored at -20°C or -80°C in a desiccated environment to maintain long-term stability and prevent premature oxidation of its methionine residues. Upon receipt, vials should be allowed to equilibrate to room temperature before opening to minimize condensation uptake.
Reconstitution should be performed using sterile bacteriostatic water or sterile phosphate-buffered saline (PBS, pH 7.4). For sensitive analytical assays requiring strict ion control, sterile deionized water may be substituted. Once reconstituted, stock solutions should be aliquoted into single-use polypropylene tubes and stored at -80°C to avoid repeated freeze-thaw cycles. Detailed guidelines on handling research compounds are hosted within our technical peptide research hub.
Analytical Quality Control: HPLC, MS, and Endotoxin Standards
PX1 Research enforces rigorous quality control protocols for all manufactured lots of MOTS-c. Purity is validated using Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC), ensuring a minimum purity threshold of 98.0%. Mass identity is verified via ESI-MS to ensure the observed molecular weight matches the theoretical value of 2174.62 g/mol within strict tolerance limits.
In addition to sequence and purity testing, every lot undergoes chromogenic LAL (Limulus Amebocyte Lysate) endotoxin testing to guarantee levels remain well below standard limits (<0.01 EU/μg). Facilities maintaining wholesale laboratory accounts receive full batch records, including raw HPLC chromatograms and mass spectra, ensuring full regulatory and analytical compliance.
Frequently Asked Questions
What is the exact sequence of MOTS-c?
The primary amino acid sequence of MOTS-c is Met-Arg-Trp-Gln-Glu-Met-Gly-Tyr-Ile-Phe-Tyr-Pro-Arg-Lys-Leu-Arg (Single-letter code: MRWQEMGYIFYPRKLR).
What is the molecular weight and formula of MOTS-c?
MOTS-c has a chemical formula of C101H152N28O22S2 and a nominal molecular weight of approximately 2174.62 g/mol (monoisotopic mass: 2173.11 Da).
What is the CAS registry number for MOTS-c?
MOTS-c is officially registered under CAS number 1627580-64-6.
How does counterion content affect MOTS-c mass calculations?
MOTS-c synthesized as a TFA salt contains trifluoroacetate counterions bound to basic residues. Net peptide content typically ranges from 70% to 85%, meaning researchers must adjust gross weight measurements to reflect actual active peptide concentration.
How should MOTS-c be stored in the laboratory?
Lyophilized MOTS-c powder should be stored at -20°C or -80°C protected from moisture and light. Reconstituted stock solutions should be aliquoted and frozen at -80°C to prevent degradation and repeated freeze-thaw cycles.
What analytical tests are provided with PX1 Research MOTS-c?
Every lot of PX1 Research MOTS-c includes a lot-specific Certificate of Analysis detailing RP-HPLC purity (≥98%), ESI-MS mass verification, and chromogenic endotoxin assay results.
What is the primary biological classification of MOTS-c?
MOTS-c is classified as a mitochondrial-derived peptide (MDP), originating from an open reading frame within the 12S rRNA region of mitochondrial DNA.
Is MOTS-c suitable for human or clinical application?
No. MOTS-c supplied by PX1 Research is strictly designated for laboratory research use, in vitro experimentation, and preclinical animal models. It is not intended for human or veterinary use.
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