A SARS-CoV-2-specific serological assay is necessary as the global pandemic persists. The ability of such an assay 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.

LifeTein’s cysteine-containing peptides helped researchers better understand the effect peptide physicochemical properties have on the pharmacokinetic profiles of the nanoparticles they are attached to. Better understanding and control of these effects is invaluable for future engineering design of many types of therapeutic nanomaterials, including for treatment of traumatic brain injuries (TBI).

Nanoparticles’ Physicochemical Properties Influenced by Peptides

Scientists at the University of California were keen on finding out what exact physicochemical properties in peptides affect the pharmacokinetics of nanoparticles designed for treating TBI. Nanoparticles are a convenient means of therapeutic drug delivery, as they can exhibit different pharmacokinetic profiles from the drug cargo in their core. This experiment analyzed how functionalizing the nanoparticles with PEG and an array of peptides with varying physicochemical properties, provided by LifeTein, contribute to the biodistribution in vivo, using a mouse model of TBI.

Results showed that the biodistribution of the modified nanoparticles varied mainly as a result of the charge of the peptides attached; basic peptides resulted in restricted distributions in the brain via convection-enhanced delivery (CED), as well as elevated off-target organ accumulation resulting in a decrease in brain accumulation when using systemic administration. In comparison, nanoparticles modified with acidic, zwitterionic, or neutral peptides demonstrated less restricted distribution in the brain via CED, and increased accumulation in injured vs. uninjured brain tissue after systemic administration.

This study suggests that the charge of peptides should be greatly taken into account when designing nanoparticles with peptide-modified surfaces. Peptides offer a great way to influence the biological interactions of nanoparticles, and understanding what physicochemical properties contribute to said influence will further advance the use of therapeutic nanoparticles in treatments like TBI.

Reference: Waggoner, L.E., Madias, M.I., Hurtado, A.A. et al. Pharmacokinetic Analysis of Peptide-Modified Nanoparticles with Engineered Physicochemical Properties in a Mouse Model of Traumatic Brain Injury. AAPS J 23, 100 (2021). https://doi.org/10.1208/s12248-021-00626-5

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The use of mobile microrobots offers a promising solution for targeted medical theranostic applications at normally inaccessible regions of the human body. Namely, the circulatory system is an ideal region for said applications, but blood flow can complicate both navigation inside the body and preservation of the microrobots.

Researchers have designed microrollers able to be controlled via magnetic propulsion and steering, able to maneuver against physiologically relevant blood flow effectively. The rollers are composed of a magnetically responsive half-side and a silica half-side for cargo loading and biochemical functionalities. Once navigated to cancerous cell monolayers, the rollers utilize surface-functionalized cell-specific antibodies as well as photocleavable linkers to release doxorubicin (DOX), and anticancer drug molecule, onto the target area.

Both the azide-DOX and o-nitrobenzyl photocleavable linker used by the team were provided by LifeTein, allowing the mircorollers to release the drug on demand via UV light exposure. This method of on demand delivery of the drug molecules combined with maneuverability of the microrollers designed by the researchers opens the door for development of next-generation microrobots for controlled navigation and cargo delivery in the circulatory system.

Reference: Alapan et al., Sci. Robot. 5, eaba5726 (2020) 20 May 2020

Phosphorylation plays a vital role in the regulation of cellular processes. Each phosphorylation pattern leads to different interactions and could result in distinct biological outcomes.

Single phosphorylated peptides are frequently used for research. However, multi-site phosphorylations play a more important role in protein-protein interaction, nuclear import and export, and many other functions.

The monophosphorylated peptides are much easier to synthesize than multiphosphorylated peptides using traditional methods. There are many reasons for the difficulties. First of all, the steric hindrance of the protected phosphorylated amino acids would decrease the coupling yield. In addition, the protecting group and cleavage conditions are very harsh for conventional methods.

LifeTein adapted the microwave-assisted heating technology for multiphosphorylated peptide synthesis. Our method increases the coupling efficiency with good yields. In our study, we utilized the optimized conditions for synthesizing peptides containing six phosphorylated amino acids.