P21 (P021)

P21 (P021) is supplied as a laboratory research reference material for in-vitro and laboratory research use only. This synthetic small peptide carries the catalog identifier P021 and is provided as a white to off-white lyophilized powder for use as an analytical reference and characterization standard in benchtop workflows.

At the molecular level, P21 (P021) is defined by the empirical formula C21H28N6O6 and a monoisotopic-consistent average molecular weight of approximately 464.5 g/mol. The active core is the tetrapeptide sequence Ac-DGGL-amide, that is, an N-terminal acetyl-capped aspartate followed by two glycine residues and a C-terminal leucine presented as the primary amide. The N-terminal acetylation (Ac-) and C-terminal amidation (-NH2) are both classic capping strategies used in solid-phase peptide chemistry to neutralize the terminal charges, reduce exopeptidase susceptibility in reference solutions, and afford a more chemically defined analyte for chromatographic and spectrometric work. The aspartate side chain contributes a single ionizable carboxyl, while the leucine residue provides a hydrophobic anchor that gives the molecule useful retention behavior on standard C18 reversed-phase columns.

Because the working sequence is short and free of cysteine, methionine, or tryptophan, P21 (P021) reference solutions are not subject to the disulfide scrambling or oxidative side reactions that complicate larger peptides; the main degradation vectors of analytical interest are aspartate-linked isomerization (Asp/isoAsp) and diketopiperazine formation at the N-terminal dipeptide junction, both of which are readily resolved by high-resolution HPLC. Purity is established at not less than 98% by HPLC, with each lot supported by a lot-specific Certificate of Analysis documenting identity (typically by mass spectrometry consistent with the ~464.5 g/mol target) and chromatographic purity.

The item is listed in-house as SKU P021 and is drawn from synthetic origin, with no animal- or human-derived starting materials. For laboratory handling and stock preparation, the lyophilized powder is generally reconstituted in an appropriate aqueous or aqueous-organic solvent system chosen by the investigator; the acetyl/amide-capped, low-molecular-weight structure of P21 (P021) makes it convenient to bracket into LC-MS method development, calibration curves, system suitability checks, and comparative peptide identity studies.

Published scientific literature has examined P21 (P021) in preclinical research; PEPTIDE.Power makes no therapeutic, diagnostic, or efficacy claims regarding this material and provides no administration or dosing guidance. This material is not a drug, supplement, cosmetic, or food, and is not for human or veterinary use, injection, or ingestion. Identity and purity are documented on the lot-specific Certificate of Analysis, available on request.

Supplied as a lyophilized (freeze-dried) powder in a sealed vial. A research reference material - not a finished product and not a delivery device. Net contents per unit are shown in the product options.

Store the sealed lyophilized powder at -20 C, protected from light and moisture. After reconstitution for laboratory use, keep cold and use promptly. Handle per standard laboratory practice; a Safety Data Sheet (SDS) is available on request.

This material is sold to qualified laboratory and research buyers for lawful research use only. It is not a drug, supplement, cosmetic, or food, and is not for human or veterinary use, injection, or ingestion. By purchasing, you confirm you are 21 or older and will use this material only for lawful laboratory research.