PNC-27 Molecular Weight, Sequence & CAS Reference
This reference sheet outlines the analytical specifications, primary amino acid sequence, molecular weight, and structural dynamics of the research peptide PNC-27. Designed for laboratory investigators, this document details chemical parameters, salt counterion impacts, and molecular mechanisms derived from preclinical research models.
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This reference sheet outlines the analytical specifications, primary amino acid sequence, molecular weight, and structural dynamics of the research peptide PNC-27. Designed for laboratory investigators, this document details chemical parameters, salt counterion impacts, and molecular mechanisms derived from preclinical research models.
Key takeaways
- PNC-27 is a synthetic chimeric research peptide designed to combine a p53-derived binding domain with a cell-penetrating transmembrane signal.
- The standard Chemical Abstracts Service (CAS) registry number commonly associated with PNC-27 in empirical chemical databases is 1380313-20-9.
- The primary structure of PNC-27 consists of a 32-amino-acid chimeric sequence.
- The chemical molecular formula of the unprotonated free-base PNC-27 peptide is C188H283N53O44S, assuming a non-oxidized methionine residue and unmodified N- and C-termini.
Chemical Overview & Primary Identification
PNC-27 is a synthetic chimeric research peptide designed to combine a p53-derived binding domain with a cell-penetrating transmembrane signal. In preclinical literature, the compound is characterized as a membrane-active agent that targets specific cell-surface markers expressed in transformed cell lines. Because synthesized peptides require precise chemical verification prior to analytical assaying, establishing the verified molecular mass, primary sequence integrity, and salt formulation is foundational for laboratory reproducibility.
Researchers evaluating PNC-27 research peptide across structural biology or membrane dynamics assays must account for its exact sequence composition and mass spectrometry profile. PX1 Research synthesizes PNC-27 under strict quality control standards within United States facilities, verifying molecular weight and primary sequence purity for non-clinical, academic, and industrial research settings.
CAS Registry Number & Salt Form Identifiers
The standard Chemical Abstracts Service (CAS) registry number commonly associated with PNC-27 in empirical chemical databases is 1380313-20-9. However, primary investigators should note that synthetic peptide CAS assignments often refer specifically to the unprotonated free base sequence, whereas commercial research preparations are standardly supplied as trifluoroacetate (TFA) or acetate salt formulations.
Because salt form directly alters raw chemical mass, analytical assays such as high-performance liquid chromatography (HPLC) and mass spectrometry (MS) must differentiate between the theoretical net peptide mass and the total bulk conjugate mass. For precise chemical matching across our catalog of research peptides, lot-specific specifications should always be confirmed against the physical documentation provided with the peptide vial.
Amino Acid Sequence and Domain Architecture
The primary structure of PNC-27 consists of a 32-amino-acid chimeric sequence. The peptide is engineered by fusing an N-terminal residue segment corresponding to the HDM-2 (human double minute 2) binding domain of human p53 (residues 12–26) to a C-terminal transmembrane-penetrating domain derived from the Antennapedia homeodomain (penetratin signal sequence).
The published single-letter amino acid sequence for PNC-27 is formatted as follows: `PPLSQETFSDLWKLLRQIKIWFQNRRMKWKK` In three-letter code notation, the sequence is represented as: H-Pro-Pro-Leu-Ser-Gln-Glu-Thr-Phe-Ser-Asp-Leu-Trp-Lys-Leu-Leu-Arg-Gln-Ile-Lys-Ile-Trp-Phe-Gln-Asn-Arg-Arg-Met-Lys-Trp-Lys-Lys-OH. The hydrophobic N-terminal motif (`PPLSQETFSDLWKLL`) enables high-affinity binding to HDM-2, while the cationic C-terminal domain (`RQIKIWFQNRRMKWKK`) facilitates cell-membrane interaction and lipid bilayer translocation.
Molecular Formula, Exact Mass, and Mass Spectrometry
The chemical molecular formula of the unprotonated free-base PNC-27 peptide is C188H283N53O44S, assuming a non-oxidized methionine residue and unmodified N- and C-termini. Based on standard atomic weight averages, the theoretical monoisotopic mass is approximately 4338.16 Da, with an average calculated molecular weight of 4341.07 g/mol (4.34 kDa).
During mass spectrometry characterization via Electrospray Ionization (ESI-MS) or Matrix-Assisted Laser Desorption/Ionization (MALDI-TOF), PNC-27 routinely exhibits multiple charge states (such as [M+3H]3+, [M+4H]4+, and [M+5H]5+) due to the abundance of basic lysine and arginine residues in its C-terminal penetratin domain. Every batch produced for PX1 Research undergoes rigorous ESI-MS verification to ensure the observed mass-to-charge (m/z) ratios strictly match theoretical spectra without significant adduct formation or truncations.
Impact of Salt Content (TFA vs. Acetate) on Net Peptide Content
During solid-phase peptide synthesis (SPPS), cleavage and HPLC purification procedures traditionally utilize trifluoroacetic acid (TFA). Consequently, lyophilized PNC-27 is typically isolated as a TFA salt, where basic amino acid side chains (Lys, Arg) and the N-terminus associate with trifluoroacetate counterions. These counterions, alongside residual bound moisture, account for a portion of the total lyophilized mass.
Net peptide content (NPC) represents the actual percentage of peptide molecules relative to total powder weight, typically ranging between 70% and 85% for standard TFA salts. When executing molar calculations or quantitative in vitro assays, researchers must adjust reconstituted liquid volume according to the net peptide purity documented on the batch-specific lot-specific Certificate of Analysis, rather than assuming 100% mass equivalence from bulk powder weights.
Preclinical Mechanism: HDM-2 Binding & Membrane Pore Formation
Preclinical studies suggest that PNC-27 exerts its cytotoxic effects on cancer cells via a distinct, non-apoptotic membrane-disruptive pathway. In vitro assays demonstrate that PNC-27 selectively binds to HDM-2 proteins overexpressed on the plasma membranes of transformed cancer cells, while non-transformed normal somatic cells express negligible membrane-bound HDM-2.
Upon target engagement with membrane-bound HDM-2, preclinical data indicate that the amphipathic alpha-helical C-terminal domain inserts directly into the lipid bilayer. This interaction induces rapid transmembrane pore formation, leading to membrane lysis, loss of osmotic integrity, and subsequent cell necrosis within minutes. Importantly, animal models and cell line experiments reveal that this pore-forming mechanism acts independently of the intracellular p53 signaling pathway, allowing PNC-27 to target p53-mutated or p53-null cancer lines in cell culture environments.
Comparative Analysis: PNC-27 vs. PNC-28 and Related Cytolytic Peptides
PNC-27 belongs to a specialized class of membrane-active, target-directed cytolytic peptides. To assist researchers in contextualizing structural variations within this research domain, the table below compares PNC-27 against closely related preclinical compounds.
In direct comparison, PNC-28 research peptide shares an identical transmembrane domain but incorporates a slightly altered N-terminal p53 sequence (residues 17–26), resulting in a lower molecular weight while maintaining HDM-2 affinity. Conversely, broad-spectrum pore-forming peptides like Melittin research peptide or human antimicrobial defense peptides like LL-37 research peptide act via non-specific lipid bilayer disruption without requiring membrane-bound protein receptor targets such as HDM-2. Researchers studying membrane dynamics can review comparative data across our broader PX1 research portal.
Handling, Storage, and Laboratory Reconstitution
Lyophilized PNC-27 should be stored at -20°C or -80°C in a desiccated environment to prevent premature hydrolysis or oxidation of the single methionine (Met27) residue. Prior to opening, vials should be allowed to equilibrate to room temperature to minimize condensation onto the dried cake.
When preparing stock solutions for cell culture or enzymatic assays, rehydrate the lyophilized powder using sterile bacteriostatic water or laboratory-grade PBS (pH 7.4). Due to the cationic nature of the penetratin domain, gentle swirling is recommended; avoid vigorous vortexing to prevent peptide aggregation or surface denaturation. To determine precise molar concentration adjustments based on salt weight and net peptide content, scientists are encouraged to utilize our interactive reconstitution calculator. Laboratories interested in bulk quantities for structural studies can set up institutional wholesale accounts for consistent batch sizing.
PX1 Research Quality Control & Manufacturing Standards
PX1 Research enforces stringent analytical testing protocols to guarantee that every batch of PNC-27 meets exact chemical specifications. Synthesized in state-of-the-art USA facilities compliant with GMP guidelines, our compounds undergo rigorous analytical verification inside an ISO 17025 accredited laboratory.
Quality assurance procedures include reverse-phase HPLC to verify chemical purity (>98%), electrospray ionization mass spectrometry (ESI-MS) to confirm exact molecular weight, and chromogenic LAL assays to ensure strict endotoxin limits (<0.01 EU/mg). This multi-layered analytical rigor ensures that laboratory investigators receive stable, reproducible research materials designed exclusively for in vitro and preclinical research applications.
Frequently Asked Questions
What is the exact molecular weight of PNC-27?
The theoretical molecular weight of the unprotonated free-base PNC-27 sequence (32 amino acids) is approximately 4341.07 g/mol (4.34 kDa). Actual lot molecular weight determined by mass spectrometry is detailed on each lot-specific COA.
What is the published amino acid sequence of PNC-27?
The published single-letter amino acid sequence of PNC-27 is PPLSQETFSDLWKLLRQIKIWFQNRRMKWKK. It combines a 15-residue N-terminal p53 binding domain with a 17-residue C-terminal penetratin signal domain.
What CAS registry number corresponds to PNC-27?
The CAS registry number assigned to PNC-27 free peptide is 1380313-20-9. Researchers should verify whether empirical data refers to the unprotonated sequence or a specific salt formulation.
How does TFA salt content affect PNC-27 net peptide mass?
Peptides synthesized via SPPS typically carry trifluoroacetate (TFA) counterions bound to basic residues. As a result, net peptide content (NPC) generally accounts for 70–85% of total lyophilized powder weight. Quantitative assays should adjust for net peptide purity.
How should PNC-27 be reconstituted for laboratory use?
Reconstitution should be performed using sterile laboratory-grade water or buffered saline (PBS, pH 7.4). Dissolve the lyophilized cake with gentle agitation, avoiding excessive vortexing to prevent peptide shearing or aggregation.
What is the primary mechanism of action investigated for PNC-27?
Preclinical studies demonstrate that PNC-27 selectively targets membrane-bound HDM-2 proteins expressed on cancer cells, inducing membrane insertion, transmembrane pore formation, and rapid cell necrosis independent of p53 pathway status.
What storage conditions maintain PNC-27 stability?
Lyophilized PNC-27 should be stored at -20°C or -80°C in a dry environment. Reconstituted aqueous aliquots should be frozen immediately to prevent degradation or oxidation of methionine residues.
How does PX1 Research verify PNC-27 purity and quality?
Every lot manufactured by PX1 Research undergoes reverse-phase HPLC purity testing (>98%), ESI-MS mass identification, endotoxin testing (<0.01 EU/mg), and third-party ISO 17025 lab verification prior to release.
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