Peptide nucleic acids (PNAs) are synthetic mimics of DNA.  The deoxyribose phosphate backbone of PNAs is replaced by a pseudo-peptide polymer. These specific physicochemical properties are exploited to develop a wide range of powerful biomolecular tools, including molecular probes, biosensors, and antigene agents. The PNA molecules can routinely be labeled with biotin, azido, cell penetration peptide fragments, or fluorophores such as FITC, Cy3, Cy5, Cy7, Alexa Dyes, and pyrene.

The uncharged synthetic backbone provides PNA with unique hybridization characteristics. It gives higher stability, or a higher thermal melting temperature (Tm) to the PNA–DNA or PNA–RNA duplexes than the natural homo- or heteroduplexes. In addition, the unnatural backbone of PNAs is not degraded by nucleases or proteases.

It was shown that the binding of PNA to complementary DNA can efficiently block transcriptional elongation and inhibit the binding of transcriptional factors. Thus, the PNAs can be used as antisense or antigene therapeutic agents. PNAs can be used as adapters to link peptides, drugs, or molecular tracers to plasmid vectors. One concept is to form the duplexes of PNAs – cell penetration peptides. The duplexes can penetrate into cells and be used in anticancer applications. The nuclear localization signal (NLS) peptide-PNAs duplexes gave a much higher nuclear localization of a coupled nuclear localization signal than did the free oligonucleotide.

The strategy of PNA-directed PCR clamping is used to inhibit the amplification of a specific target. This PNA–DNA complex formed at one of the primer sites effectively blocks the formation of the PCR product. The procedure can be used to detect single base-pair gene variants for mutation screening and gene isolation. The biotinylated short PNA probes can be used as generic capture probes for the purification of nucleic acids via streptavidin beads. Other applications could be solid-phase hybridization, and fluorescence in situ hybridization (PNA-FISH).

PNA-based applications benefit from the unique Physico-chemical properties of PNA molecules, enabling the development of cell penetration peptide-PNA assays in molecular genetics. 

Reference

Adult type 2 diabetics are at very high risk of obesity-associated hypertension, where the end result can be as grave as heart failure. The systems involved in the human body regarding these conditions can be complex, but scientists have identified cases of stroke and refractory hypertension that harbored increased plasma IgG, 5-hydroxytryptamine 2A receptor (5-HT2AR)-targeting autoantibodies.

Serotonin 2A-Receptor Decoy Peptide Lowers Blood Pressure

The goal was to test whether a decoy receptor peptide could lower blood pressure in an animal model of obesity-associated hypertension. The team developed the decoy receptor peptide, SCLLADDN (Sertuercept), and LifeTein synthesized it successfully for the project. Using Zucker hypertensive diabetic fatty rats as the model, the team proved their theory.

Results showed after implementing the decoy receptor peptide, acute and long-lasting significant systolic and diastolic blood pressure-lowering occurred within the rat models. This followed through without any long-term side effects after chronic administration. Hopefully, these results are fruitful in later applications and the same peptide can be used to help significantly lower blood pressure in humans afflicted with type 2 diabetes as well.


Zimering MB. A Serotonin 2A-Receptor Decoy Peptide Potently Lowers Blood Pressure in Male Zucker Diabetic, Fatty, Hypertensive Rats. Endocrinology, Diabetes and Metabolism Journal. 2021 Aug;5(2). DOI: 10.31038/edmj.2021523. PMID: 35035793; PMCID: PMC8759716.

A linear synthetic peptide, SCLLADDN (SN..8 or P4) having a sequence
identical to that of a fragment of the second extracellular loop region of the human 5-
hydroxytryptamine 2A receptor was synthesized at Lifetein, Inc (Hillsborough, NJ) and
had > 95% purity. Substitutions of SCLLADDN containing a single alanine amino acid
replacement, e.g. SALLADDN, SCLLADAN were synthesized at Lifetein, Inc (Hillsborough,
NJ) and had purity of > 95%.

Grinberg, M.; Burton, J.; Pang, K.C.; Zimering, M.B. Neuroprotective Effects of a Serotonin Receptor Peptide Follow-ing Sham vs. Mild Traumatic Brain Injury in the Zucker Rat. Preprints 2023, 2023050004. https://doi.org/10.20944/preprints202305.0004.v1

Alzheimer’s disease as we know it today is a horrible and currently incurable neurodegenerative disorder characterized by neuronal loss, memory impairment, and cognitive decline. Ongoing research is always looking for ways to combat or slow down this disorder, and one such area of interest is the related formation of senile amyloid plaques mainly composed of amyloid β (Aβ) peptides, whose aggregation is thought to be responsible for Alzheimer’s disease pathology. Researchers are implementing gallium nitride nanoparticles as a means to inhibit the formation of the Aβ40 amyloid peptides.


Gallium nanoparticles inhibit amyloid β peptide formation

LifeTein supplied the scientists with the Aβ40 peptide necessary for this research, where they would synthesize their nanoparticle with gallium nitrate and observe its inhibition on the peptide in vitro. Gallium nitrate in particular is of interest due to its biocompatibility and aqueous stability, allowing the substance to be useful in numerous biological applications.

After observing their interactions together using the likes of ThT fluorescence, CR absorbance, turbidity, and SEM imaging, the group concluded that the nanoparticle did in fact inhibit the crucial oligomeric nucleus formation of the amyloid β peptide. The group believes a key factor in this is the polarization characteristic of the nanoparticle, where even more polarization could mean more interaction between the nanoparticle and the peptide, and thus less intermolecular interactions among the Aβ40 peptide monomers to form amyloids. Hopefully the future sees more studies on these gallium nitrate nanoparticles, and how further modifications could benefit the fight against Alzheimer’s through these critical Aβ40 peptides.

Torres, K. M., Delgado, A. S., Serrano, E. R., Falcón-Cruz, N. V., Meléndez, A., Ramos, I., Du, D., & Oyola, R. (2021). Gallium nanoparticles as novel inhibitors of Aβ40 aggregation. In Materials Advances (Vol. 2, Issue 16, pp. 5471–5478). Royal Society of Chemistry (RSC). https://doi.org/10.1039/d1ma00461a

A SARS-CoV-2-specific serological assay is necessary as the global pandemic persists. The ability of such an assay and synthetic spike protein to quantify virus antibodies in high and low COVID-19 incidence communities has a multitude of benefits. These include assessment of exposure rates to the virus, the immune responses to vaccination, and the longevity of antibodies from either infection or vaccination.

Spike Protein Peptide Helps Develop Multiplex Assay

Scientists used multiple resources to develop their SARS-CoV-2 specific serological assay, including a synthetic peptide of the RBD region of the Spike protein (synthetic RBD) by LifeTein. Overall, the assay proved highly sensitive and specific in monitoring the immune response and antibodies in both individuals and communities.

Some innate limitations to this kind of assay would be cross-reactivity with other human coronaviruses, though this was not an issue in the small control group used in Ithaca. The amount of information attainable from the assay will help immensely in the future of this pandemic, as being able to assess infection risks in the population will save countless through precautions.

Guarino C, Larson E, Babasyan S, Rollins A, Joshi LR, Laverack M, et al. (2022) Development of a quantitative COVID-19 multiplex assay and its use for serological surveillance in a low SARS-CoV-2 incidence community. PLoS ONE 17(1): e0262868. https://doi.org/10.1371/journal.pone.0262868

A common strategy for nanomaterials to enter the cell has always been covalent coupling with cell-penetrating peptides (CPPs). While effective, it is not always desirable to make chemical modifications to the nanoparticles. Recently, cationic CPPs have been shown to stimulate cellular uptake of nanoparticles via co-administration. This effect, labeled the bystander manner, allows for nanoparticles to enter the cell with CPPs without chemical modification.

CPPs facilitate Nanoparticle entry into cells

Using CPPs synthesized by LifeTein, scientists wanted to explore if amphiphilic and hydrophobic CPPs were as effective as cationic CPPs at facilitating nanoparticles into the cell via the bystander manner. After testing the peptides used in the table above on mice, they found the amphiphilic Transportation Peptide (TP) was a very effective CPP for increasing the cellular uptake of nanoparticles in this fashion.

Though more research needs to be completed down the line to fully understand all of the components of TP-mediated bystander uptake, this stands as a new and effective method to increase the intracellular delivery efficiency of nanoparticles.


Li, Y.-X.; Wei, Y.; Zhong, R.; Li, L.; Pang, H.-B. Transportan Peptide Stimulates the Nanomaterial Internalization into Mammalian Cells in the Bystander Manner through Macropinocytosis. Pharmaceutics 2021, 13, 552. https://doi.org/10.3390/pharmaceutics13040552

Expression of human endogenous retroviruses (HERVs) shows potential for peptide derivatives to be used as biomarkers for prostate cancer. Specifically, peptides from HERV-K and HERV-H Proteins show association in prostate cancer pathogenesis.

HERV Peptides as Biomarkers for Prostate Cancer

With prostate cancer being the most common cause of death by cancer in males, there is a need to identify aggressive tumors that current diagnostic tests do not measure up to. Scientists looked toward the envelope protein of HERV family viruses, well known for its immunosuppressive properties and role in modulating transcription factors of cancer-associated pathways. LifeTein synthesized the peptide derivatives of this protein, where HERV-K and HERV-H especially showed promise as prostate cancer biomarkers.

The findings suggest these HERV peptides have capabilities for their serum autoantibodies to further investigate the expression levels of the envelope protein of HERV-K and HERV-H in biopsy samples. It remains ever exciting to watch the continuously-growing usefulness of peptides expand into more and more fields, and hopefully use as Biomarkers is far from the last.

Manca, M.A.; Solinas, T.; Simula, E.R.; Noli, M.; Ruberto, S.; Madonia, M.; Sechi, L.A. HERV-K and HERV-H Env Proteins Induce a Humoral Response in Prostate Cancer Patients. Pathogens 2022, 11, 95. https://doi.org/10.3390/pathogens11010095

LifeTein was awarded the fastest peptide synthesis service in 2021 by New World Report, thanks to our speedy custom protein, antibody, and chemical services for biotech, pharma, academia, government customers, and diagnostics.

New World Report is an informative business news platform that covers businesses all throughout the Americas. Each year they honor the best of the best in their North America Business Elite awards, acknowledging the talent and accomplishments in businesses from any scale or field. Being recognized as the Fastest Peptide Synthesis Service is a tremendous honor for LifeTein.

LifeTein provides the fastest turnaround time and most reliable quality in the industry,
using our proprietary microwave-assisted heating technology for peptide synthesis. The
microwave can instantly heat any solvent or amino acids in solution through dipolar rotation or ionic conduction, resulting in a more efficient, more precise, and safer heating mode for peptide synthesis.

With LifeTein leading the way within this industry, you can expect us to continue the
path of innovation at the same high quality we have always given.

Methicillin-resistant Staphylococcus pseudintermedius (MRSP), a zoonotic pathogen causing severe skin infection, has been shown to be combated by peptides with antimicrobial and anti-inflammatory properties. The phenol-soluble modulin beta (PSMβ) peptides that succeed where conventional drugs fall short are isolated from a unique strain (S. felis C4) found in feline skin.

Antimicrobial Peptides from Feline Skin

Once the PSMβ peptides were identified from the S. felis strain, LifeTein helped the scientists by synthesizing batches of the peptides to be tested against MRSP in mice. Results showed a significant reduction in necrotic skin injury from MRSP in mice treated with the S. felis extract. This was due to the antimicrobial peptides inhibiting translation and disrupting bacterial cell membranes, greatly reducing skin colonization of MRSP.

The group believes this study can re-establish the community of microbes on the skin that promote health. The results proved effective in vitro and in vivo when combatting MRSP. Overall, the discovery serves to represent a potential bacteriotherapeutic for both human and animal skin diseases like MRSP colonization and infection.

In a new study, Williams shows that the skin microbe Staphylococcus epidermidis can produce phenol-soluble modulins (PSMs) that will induce skin inflammation. These PSMs combine with cysteine proteases to promote skin disease.

1. SE PSMa:fMADVIAKIVEIVKGLIDQFTQK.
2. SE PSMd:fMSIVSTIIEVVKTIVDIVKKFKK.
3. SE PSMε:fMFIINLVKKVISFIKGLFGNNENE.
4. SE d-toxin:fMAADIISTIGDLVKWIIDTVNKFKK.
5. S.aureus PSMa3:fMEFVAKLFKFFKDLLGKFLGNN.
   f = N-terminal formylation

Williams metal., 2023, Cell Reports 42,113024 September 26, 2023 https://doi.org/10.1016/j.celrep.2023.113024

O’Neill AM, Worthing KA, Kulkarni N, et al. Antimicrobials from a feline commensal bacterium inhibit skin infection by drug-resistant S. pseudintermedius. Elife. 2021;10:e66793. Published 2021 Oct 19. doi:10.7554/eLife.66793

Nephrilin peptides have proven to have several beneficial systemic effects in rodent models of stress, burn, and sepsis by reducing present pro-inflammatory factors. Scientists in Sunnyvale, CA were keen on testing these nephrilin-class peptides on models of respiratory distress, applying their beneficial properties to rat scald-endotoxemia models. LifeTein synthesized specially designed peptides with Valproic acid covalently attached to the N-terminus to be tested on the scald-endotoxemia models.

Valporic Acid Enhances Nephrilin Peptides

Three peptides in total were synthesized for the group by LifeTein, Nmod3sN1v, Nmod3N1vA, and Nmod3N1vAS3, whose sequences can be seen in the figure. The latter two peptides differ from Nmod3sN1v in that they contain the tripeptide sequence d(AVD), since the tripeptide has shown to dramatically improve iron-binding in vitro. Nmod3N1vAS3 differs from Nmod3N1vA in that it contains a Y*LK motif (where Y* is phosphotyrosine). This motif was previously shown to inhibit STAT3 activation, a suspected role in lung inflammation pathology.

After treating the rat scald-endotoxemia models with the peptides, the group concluded that the Nmod3N1vA and Nmod3N1vAS3 peptides were superior than the Nmod3sN1v sequence in the following readings: protease-stability, biodistribution to lung tissue, amelioration of catabolism, early inflammation and insulin-resistance, activated lymph node dendritic / T-cells, breathing difficulty (by oximetry), lung edema, granulocyte count and IL1-beta in BAL fluid, systemic oxidative stress and kidney function. The group concluded that when compared to the original nephrilin peptide, these designs are at least ten times more potent by weight. The study showcases the potential these peptide designs hold for future drug development, especially in respiratory models and burn damage.

References: Desmond D. Mascarenhas, Puja Ravikumar, Edward P. Amento, N-modulin peptides attenuate respiratory distress in a scald-endotoxemia model, Burns Open, Volume 6, Issue 1, 2022, Pages 1-6, ISSN 2468-9122, https://doi.org/10.1016/j.burnso.2021.09.001.

Neurodegeneration in postmortem patients of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) has been correlated to distribution of dipeptide repeat proteins in the form of poly-GR. Scientists at the Erasmus University Medical Center Rotterdam have assessed the toxicity of poly-GR and found a possible suppression with the help of zebrafish, Trolox, and LifeTein’s own GR peptides and antibodies.

Trolox Suppresses Poly-GR Toxicity Identified by Antibodies

Using zebrafish as a model for C9FTD/ALS cases, scientists injected the embryos with RNA encoding ATG mediated codon-optimized 100xGR. These peptides provided by LifeTein were able to simulate the apoptosis in the brain and caused aberrant motor neuron morphology in the zebrafish embryos. Using LifeTein’s monoclonal antibody against poly-GR, the group was able to detect the poly-GR specifically in the brain.

The researchers’ study suggested inhibition of oxidative stress held the potential to suppress the poly-GR toxicity in these models. To apply this knowledge, the embryos were treated with Trolox, a known inhibitor of oxidative stress. Not only did this rescue the poly-GR toxicity, but it did so in vivo. This holds a promising future in treatment of C9FTD/ALS patients, indicating the possible role of oxidative stress implies the possible treatment by inhibiting the said stress.

References: Riemslagh FW, Verhagen RFM, van der Toorn EC, Smits DJ, Quint WH, van der Linde HC, van Ham TJ, Willemsen R. Reduction of oxidative stress suppresses poly-GR mediated toxicity in zebrafish embryos. Dis Model Mech. 2021 Oct 25:dmm.049092. doi: 10.1242/dmm.049092. Epub ahead of print. PMID: 34693978.