Influenza A is a virus responsible for multiple pandemics over the last centuries, the respiratory disease has claimed millions of lives over the course of human history. Though other pandemics may come to mind in recent years, flu season is just starting up again now as the weather gets chillier. While we can fight back the virus on a yearly basis, more understanding is requited for a long-term victory. A team has been researching into the NS1 protein of the virus, the part responsible for downregulating the antiviral response of host cells to facilitate viral replication. They believe their work has revealed information on the vital role of 14-3-3γ in influenza A virus replication, where the isoform was found to interact with the protein.
Truncated N-Terminus interacts with 14-3-3γ
The group preformed much work such through immunoprecipitation to show the interactions between 14-3-3γ and the influenza A encoded NS1 protein. Some of their most compelling finds was the inhibition of 14-3-3γ expression in the host cells greatly reduced replication of the PR8 wild-type virus, but had no such effect on the R8-NS1/1-98 mutant virus, which lacks most of the effector domain of NS1. LifeTein was able to provide the group with anti β-tubulin antibodies, which assisted in their immunoprecipitation methods.
The team insists that the evidence points directly towards the vital role of 14-3-3γ in influenza A virus replication thanks to the NS1 protein. While they are still unclear on the precise mechanisms of these interactions, they are certain the findings have laid out the groundwork for future pivotal studies involving influenza A and the role of 14-3-3γ in infection.
Kuo, R.-L.; Tam, E.-H.; Woung, C.-H.; Hung, C.-M.; Liu, H.-P.; Liu, H.M.; Wu, C.-C. Interactome Profiling of N-Terminus-Truncated NS1 Protein of Influenza A Virus Reveals Role of 14-3-3γ in Virus Replication. Pathogens 2022, 11, 733. https://doi.org/10.3390/pathogens11070733
The concept of self-assembling peptides is a promising front where construction of devices can be achieved through a single molecule. While the outcome is enticing, the means to reach a consistent outcome are complex to say the least. Dozens of factors go into how a peptide may self-assemble and fold, with the most important being the sequence itself. While this can be handled by careful screening and simulations, the interface at which this folding occurs becomes more important to consider at well. Researchers looked to test how specific peptides fold and self-assemble on graphite-water interfaces, where a number of factors give this method the advantage over doing so in free solution.
Graphite helps peptides self fold into conformations
The group studying this phenomenon claimed that the folded conformations of the peptides were stable over a variety of temperatures when observed over graphite. They point out that it is due to the peptide backbone aligning with the zigzag directions of the graphite plane, thus allowing the conformations to occur more favorably from the intermolecular hydrogen bonds of the molecule. Atomic force microscopy revealed these theories to be true beyond initial simulations as well.
The team believes the design principles displayed in these experiments could be of great use in future iterations of self-assembling peptide engineering. The thermodynamically favored self-assembly with the use of a graphite-water interface shows promise as a medium for even more complex molecular devices in the future, a future LifeTein is looking forward to being a part of.
Justin Legleiter, Ravindra Thakkar, Astrid Velásquez-Silva, Ingrid Miranda-Carvajal, Susan Whitaker, John Tomich, and Jeffrey Comer Journal of Chemical Information and Modeling 2022 62 (17), 4066-4082 DOI: 10.1021/acs.jcim.2c00419
The Nobel Prize in Chemistry 2022 awarded to Carolyn R. Bertozzi, Morten Meldal, and K. Barry Sharpless for their outstanding work with click chemistry, a well-deserved honor for developing a vital and straightforward technique in modern chemistry. Barry Sharpless, with this as his second Nobel Prize in Chemistry, and Morten Meldal independently presented the idea of click chemistry over twenty years ago. The reactions involved are highly versatile and can be performed under a multitude of conditions, making the method incredibly efficient and applicable to many fields. In a perfect example, Carolyn Bertozzi, who was jointly awarded this Nobel Prize, utilized the principles of click chemistry to present bioorthogonal chemistry, click reactions that take place within living organisms without disrupting the normal chemistry of the cell. Since its inception, click chemistry has had its influence explored across many other facets of chemistry, including very useful applications in peptide synthesis.
LifeTein frequently uses this CuAAC reaction in its oligonucleotide-peptide conjugation service. Such reactions would not be nearly as feasible without the simple answer of click chemistry, as linking large and functionalized molecules like peptides and oligonucleotides is a very challenging task otherwise. With this, LifeTein is able to provide DNA-peptide conjugates and RNA-peptide conjugates for cell screening and in vivo studies with ease.
Congratulations again to Carolyn R. Bertozzi, Morten Meldal, and K. Barry Sharpless on their joint award for The Nobel Prize in Chemistry 2022, the field wouldn’t be anywhere near where it is today without click chemistry.
Lyme disease is an abundantly present vector-born disease, with nearly 400,000 new cases in the U.S. diagnosed each year. While treatment with antibiotics is effective, if the disease goes unnoticed and unchecked it can lead to lifelong damage to the nervous and musculoskeletal system. Hence, it is critical to detect the disease as early as possible, however this becomes a complex issue since not every case results in erythema migrans (EM), the characteristic skin lesion of Lyme disease. This issue is further complicated since current serodiagnostics lack sensitivity in early Lyme disease detection, when treatment would be the most effective. One group sought to solve this issue by developing a method more sensitive and more specific than the current ones, ultimately using linear peptide epitomes to better diagnose Lyme disease.
Linear peptide epitomes lead to higher specificity and sensitivity in Lyme disease assays
LifeTein synthesized peptides from prominent B. burgdorferi antigens expressed during human infection of Lyme disease for the group to utilize. Their idea is to use synthetic peptides that contain the linear epitomes necessary, rather than protein antigens that often have cross-reactive epitomes. Eliminating the cross-reactive epitomes leads to more specificity within the tests, and more sensitivity as well. While the results for the single peptide epitomes were less than anticipated, the group found that using the epitome peptides in pairs resulted in the specificity and sensitivity they had hypothesized.
Diagnostic assessment of Lyme disease is in dire need of an improvement to efficiently catch it in the early stages, and these linear peptide epitomes are shaping to be a key part of the solution. The group hopes that their research will allow future works to improve upon their studies and one day include the linear peptide epitomes as part of a potential multi-peptide-based assay for the laboratory diagnosis of Lyme disease.
Arnaboldi PM, Katseff AS, Sambir M, Dattwyler RJ. Linear Peptide Epitopes Derived from ErpP, p35, and FlaB in the Serodiagnosis of Lyme Disease. Pathogens. 2022; 11(8):944. https://doi.org/10.3390/pathogens11080944
As the world moves on through the ongoing pandemic that is COVID-19, great minds across every field and corner of the world are doing their part to further our collective understanding of the virus. A recent study specifically took greater notice in the population of antibodies increasing in more sever cases of COVID-19 over mild ones. Specifically, there was a study conducted on the higher HERV-W and IFN-I antibody presence detected in intensive care COVID-19 patients, utilizing peptides for the experiment.
HERV-W and IFN-I antibody presence higher in severe COVID-19 cases
LifeTein supplied the group with the HERV-W-env(248–262), IFN-α, and IFN-ω peptides necessary for the report. Not only did the studies prove higher levels of anti-IFN-I autoantibodies and HERV-W antibodies are much more prevalent in severe COVID-19 cases than in mild ones, but it opened up a new perspective on how the humoral responses against HERV-W-env(248–262) and IFN-α are correlated across ICU patients. Hopefully, this research leads to more beneficial breakthroughs over time, for COVID-19 cases and potentially other life-threatening conditions as well.
Simula, E. R., Manca, M. A., Noli, M., Jasemi, S., Ruberto, S., Uzzau, S., Rubino, S., Manca, P., & Sechi, L. A. (2022). Increased Presence of Antibodies against Type I Interferons and Human Endogenous Retrovirus W in Intensive Care Unit COVID-19 Patients. In H. H. Mostafa (Ed.), Microbiology Spectrum. American Society for Microbiology. https://doi.org/10.1128/spectrum.01280-22
Analyzing cell interactions was always vital for biological studies, but a simple approach from microscopy fails to provide any information on receptors and ligands involved in these interactions. Scientists have developed a method of bacterial sortase labeling involving a fluorescent LPXTG peptide motif and Staphylococcus aureus transpeptidase Sortase A (SrtA) that can be readily detected using flow cytometry. The group coined this approach as Labeling Immune Partnerships by SorTagging Intercellular Contacts, or LIPSTIC for short. LIPSTIC is even more useful in the fact that the LPETG peptide and SrtA reaction allows analysis of cell-cell interactions both in vitro and in vivo.
LPETG peptide and SrtA reaction to label receptor and ligand interactions.
LifeTein supplied the group with the necessary Biotin-ahx-LPETG peptide, where in the LIPSTIC method a ligand or receptor of note that is fused with a tag consisting of five N-terminal glycine residues (G5) has the fluorescent peptide donated to it by the SrtA. The acceptor cell can then be monitored via the label after separation. The group is confident that LIPSTIC is an efficient method to label receptor-ligand interactions both in vitro and in vivo, even able to detect rare or low-intensity interactions.
Pasqual G, Chudnovskiy A, Tas JMJ, Agudelo M, Schweitzer LD, Cui A, Hacohen N, Victora GD. Monitoring T cell-dendritic cell interactions in vivo by intercellular enzymatic labelling. Nature. 2018 Jan 25;553(7689):496-500. doi: 10.1038/nature25442. Epub 2018 Jan 17. PMID: 29342141; PMCID: PMC5853129.
Platinum based anticancer drugs generally go hand-in-hand with DNA, however their interactions with proteins are important to understand as well. A group focused their work on discovering and further exploring binding sites of cisplatin onto both an oligonucleotide and two peptides corresponding to segments of H2A and H2B histone proteins via mass spectrometry. The study revealed key interactions and the mechanism of cisplatin binding with oligonucleotides and peptides, and eventually DNA as well.
Peptide and oligonucleotide competitive binding with platinum
LifeTein supplied the group with two peptides for the project; P1, from the acidic region of H2a, and P2, from the α2-helix of H2B human histone protein. These peptides and an oligonucleotide model of DNA were analyzed using electrospray ionization high-resolution mass spectrometry and tested with substantial theoretical figures to match the fragments. Here the group found the preferred binding sites on both of the peptides and the oligonucleotide, of relevance are the multiple histidine and methionine residues on P2 that saw the most binding to cisplatin over P1.
The adducts formed on platinated P2 were tested and incubated solely with the oligonucleotide, where after two days the group found that a portion of the platinum fragments had migrated from the peptide to the oligonucleotide. This observation not only showed that the oligonucleotide was perhaps the more thermodynamically favored product, but also gave insight into how the cisplatin drug takes to DNA during chemotherapy, by binding to the proteins first and then reversing the reaction and migrating. The long-term implications of this mechanism will surely be researched and explored in the future of platinum drug delivery and cancer treatment.
Mansouri, F., Patiny, L., Ortiz, D. et al. Simultaneous mass spectrometry analysis of cisplatin with oligonucleotide-peptide mixtures: implications for the mechanism of action. J Biol Inorg Chem 27, 239–248 (2022). https://doi.org/10.1007/s00775-022-01924-9
Glioblastoma (GBM) is the most commonly occurring terminal brain cancer. Due to complications in the brain like the blood brain barrier, methods of treating GBM are few and far between. Therefore, treatment in the region is generally left to specific chemotherapeutics like temozolomide (TMZ), which has the unique capability to bypass the brain blood barrier. However, matters become more complicated as many subpopulations of GBM, namely the glioma stem cell populations, are resistant to TMZ. Researchers are looking into ways to bypass this resilience, namely connexin 43 (Cx43) hemichannels that when inhibited by mimetic peptides allow the glioma stem cell populations to be treated significantly more effectively by TMZ
Cx43 mimetic peptides weaken cancer’s resistance to TMZ
Researchers used LifeTein’s peptide synthesis service to create two mimetic peptides of Cx43, αCT11 and αCT1, to inhibit Cx43 hemichannels and then sensitize the glioma cells and other GBM cell populations to TMZ in a 3D hyaluronic acid and collagen hydrogel-based tumor organoid system. After testing this model extensively, the group found that only the αCT1 peptide in combination with TMZ proved effective in treating the cell lines. It is believed that the αCT1 is more successful due to its cell penetrating sequence when compared to αCT11.
Overall, the group emphasizes that the model used does not accurately mimic the cellular heterogeneity of GBM, but the results are a fantastic start and can be used as a tool to further study treatment of this aggressive brain cancer. Further work can optimize this treatment and can hopefully provide a chance for those who have to go against this fatal ailment.
Jingru Che, Thomas J. DePalma, Hemamylammal Sivakumar, et al. αCT1 Peptide Sensitizes Glioma Cells to Temozolomide in a Glioblastoma Organoid Platform. Authorea. April 29, 2022.
After the gut, the mouth is most important microbiome in the human body, with the inhabitants ranging from bacteria and fungi to viruses and protozoa. If this careful balance of microorganisms is thrown off even by a little, certain pathogens could propagate and cause serious periodontal diseases. One such pathogen is Porphyromonas gingivalis (P. gingivalis), that degrades the components of the specialized basal lamina that protects supporting tissues in the teeth. However, one component of this specialized basal lamina, the secretory calcium-binding phosphoprotein proline-glutamine rich 1 (SCPPPQ1) protein, had shown to be not only resistant to P. gingivalis, but to also affect the cell membrane of P. gingivalis itself. A group of researchers then decided to explore these antimicrobial properties of the SCPPPQ1 protein and its peptide derivatives.
SCPPPQ1 protein and peptide derivatives as antibacterial agents
Using the SCPPPQ1 protein itself and derived peptides synthesized by LifeTein, the group sought to test how they fared against P. gingivalis in isolated conditions. After incubating the two together, results showed rapid and significant decrease of P. gingivalis population. The means of which were narrowed down to aggregation of bacteria and membrane disruption.
The group went further and tested the antibacterial properties against other pathogens, and though there were results, none were as significant as those against P. gingivalis. The results point towards a more honed treatment against P. gingivalis in the future using this knowledge of the SCPPPQ1 protein and its peptide derivatives. Since the protein itself is native in the human mouth, further application to treat periodontal pathogens with its antibacterial properties is not out of the question.
Mary, C., Fouillen, A., Moffatt, P. et al. Effect of human secretory calcium-binding phosphoprotein proline-glutamine rich 1 protein on Porphyromonas gingivalis and identification of its active portions. Sci Rep 11, 23724 (2021). https://doi.org/10.1038/s41598-021-02661-w
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.
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.