01 / Molecular architecture
A closer look at the chain.
RT has a 39-residue backbone with nonstandard residues, a lysine-linked side chain and an amidated end. These features belong to its chemical identity, rather than being separate ingredients. [1][4]
- 1Y
- 2Aib
- 3Q
- 4G
- 5T
- 6F
- 7T
- 8S
- 9D
- 10Y
- 11S
- 12I
- 13α-MeLeu
- 14L
- 15D
- 16K
- 17K*
- 18A
- 19Q
- 20Aib
- 21A
- 22F
- 23I
- 24E
- 25Y
- 26L
- 27L
- 28E
- 29G
- 30G
- 31P
- 32S
- 33S
- 34G
- 35A
- 36P
- 37P
- 38P
- 39S
Read the modifications
2 & 20 · Aibα-aminoisobutyric acid.
13 · α-MeLeuα-methylleucine.
17 · K*Lysine bearing an AEEA–γ-Glu–C20 diacid side chain.
39 · Ser–NH₂Amidated C-terminal serine.
The cited sequence record is for a sodium salt. Confirm the supplied form separately; this diagram does not establish Pioneer lot identity. [1]
02 / Laboratory evidence
Three targets. Separate measurements.
Triple agonism describes activity at three receptor targets. It does not imply equal activity or a mixture of three peptides. Each target must be evaluated in its own assay context. [2]
Where the molecule fits
Li and colleagues resolved three receptor complexes bound to RT using cryo-electron microscopy. Their structures show shared contacts alongside receptor-specific differences in how the peptide is accommodated.
Scope: the prepared receptor complexes, not the composition of a commercial vial. [2]
What changes the signal
The same study altered selected receptor residues and measured changes in cAMP signaling. This connects proposed molecular contacts with a measurable response in a cell-based assay.
Scope: the tested constructs and readout; one signaling endpoint is not a complete activity profile. [2]
Binding, signaling and potency: the difference
A structure describes molecular arrangement. A signaling assay measures a response. EC₅₀ describes the concentration associated with half of the fitted maximum response in a particular assay; it is not a purity percentage.
When comparing results, keep the receptor construct, readout, reference control and experimental conditions together. A value without its method is an incomplete comparison.
03 / Analytical documentation
A result needs a method.
Start with the question the test answers. Identity, purity and quantitative content are distinct analytical purposes. Method suitability depends on what is being measured and what could interfere. [3]
- Identity
- What material does the evidence support? Read the identification method, reference and chemical form.
- Purity & impurities
- What does the method separate or detect? Keep the reported percentage with its method and calculation basis.
- Content
- How much analyte was measured? Look for units, calibration, sample basis and the reported result.
ICH Q2(R2) discusses specificity, accuracy, precision and other characteristics used to evaluate analytical procedures. It is a method-validation reference, not a certificate for this catalog. [3]
What a reference cannot tell you
A published sequence, receptor study or supplier listing cannot fill a missing result on your batch certificate. A result is only traceable when the material, lot and report can be matched.
Read a lot record in four steps
- Match the material name and batch identifier to the vial.
- Check the laboratory, report date and original document.
- Read each method, result, unit and stated acceptance criterion.
- Ask for clarification where identity, chemical form or a requested measurement is missing.
Handling & storage notes
Lyophilized material: Store at −20°C; protect from light and moisture.
Follow the material-specific label and supporting storage documentation. These temperatures do not establish a shelf life.
How to store lyophilized peptides04 / Reference questions
A few details, clarified.
Are RT and LY3437943 the same material?
RT is the catalog name used here, and LY3437943 is the research identifier used in the literature. A name match is the starting point for checking documentation; it does not replace confirmation of the supplied chemical form.
Is a triple agonist a three-component blend?
No. Here, triple describes the receptor profile of one modified peptide. A blend contains separate molecular components and needs a composition record for each.
Does the chain diagram show the whole chemical structure?
It shows residue order and marked modifications. The legend records the side-chain attachment and terminal amide. It is not a three-dimensional model, and it does not specify the counterion or water content of a supplied lot.
Does a purity percentage tell me the amount in the vial?
Not by itself. Read what was measured, the method, units and reporting basis. A reported chromatographic percentage and a quantitative content result answer different questions; a label claim needs its own supporting measurement.
Can another supplier’s storage specification be used for this material?
Use documentation for the actual supplied formulation. Record the lot and consult its label and any storage or stability information supplied with it. A shared name or lyophilized appearance is not enough to transfer a shelf-life claim.
05 / Source notes
Go to the source.
References support the statements identified above. External publications have a broader scope than the molecular and analytical topics summarized here.
- Cayman Chemical · RT (LY3437943) sodium-salt referenceSupplier reference · Read source (opens a new tab)
Sequence and chemical modifications. Supplier reference specifications are not Pioneer lot results.
- Li et al. · Cell Discovery, 2024Published research · Read source (opens a new tab)
Receptor-complex structures and cell-based signaling experiments. This guide discusses the molecular and in-vitro findings only.
- ICH Q2(R2) · Analytical procedure validationStandard or guideline · Read source (opens a new tab)
Analytical terminology and method-validation principles. Referencing this guidance does not certify a Pioneer method or product.
- FDA GSRS · RT substance record, UNII NOP2Y096GVPublic record · Read source (opens a new tab)
Substance identity and registry identifiers, including the 39-residue chain length. A public record is not a Pioneer lot result.