Hydrophobic Sequence Research Articles

A novel deep eutectic solvent-based green extraction and purification of DPP-IV inhibitory peptides from tilapia (Oreochromis niloticus) viscera hydrolysate

The use of green and low-cost techniques to produce bioactive peptides with anti-diabetic properties from protein-rich fish waste is a sustainable way to manage agro-fishery and food industrial waste. This study investigated a novel ultrasound (UL) assisted deep eutectic solvent (DES) based extraction approach to recover bioactive protein-rich extracts from tilapia fish viscera waste under optimized conditions (52.52% ultrasound amplitude, 1:4 DES molar ratio, 25 min extraction time). The aqueous two-phase system (ATPS) method successfully concentrated the crude proteins in the top phase and back-extracted proteins to the bottom phase with a high recovery yield. Hydrolysis by Alcalase produced tilapia viscera protein hydrolysate (TVPH) with low molecular weight (MW) peptides and low dipeptidyl peptidase (DPP)-IV half-maximal inhibitory concentration (IC50) value of 1.57 ±0.16 mg/mL. Notably, TVPH-3 fraction and TVPH-3-2 sub-fraction exhibited appreciable DPP-IV IC50 values of 1.36 ±0.08 mg/mL and 0.42 ±0.01 mg/mL, respectively. Ultrafiltration combined with RP-HPLC enriched the DPP-IV inhibitory concentration of the individual protein fractions. TVPH-3-2 sub-fraction contained hydrophobic amino acids and peptide sequences with typical DPP-IV inhibitory peptide sequence motifs. The results presented in this study indicate that tilapia viscera biomass is a potential source for protein recovery aided with a green extraction approach, and tilapia viscera protein-derived hydrolysates have potential applications as a potent functional food ingredient for the management of metabolic diseases like type-2 diabetes.

Modulating the self-assembly morphologies of bola peptides through strategic positional shifts of hydrophobic amino acids

In nature, the switching of two adjacent amino acids usually leads to the protein fold differently, thus affecting their biological functions. Previous studies mainly focus on the sequence effect of the hydrophilic amino acids, while the effect of the hydrophobic amino acids alternation has not been extensively investigated. Therefore, we report here the effect of the V position in the hydrophobic region on the self-assembly behavior of the four isomers with the same composition but different hydrophobic amino acid sequence. The results demonstrated that the shift of V residue from C-terminal to N-terminal had a great effect on the final self-assembling morphologies, monolayer nanotubes were dominant structures for Ac-KIIIVK-NH2 (KIIIVK) and Ac-KIIVIK-NH2 (KIIVIK). In contrast, Ac-KIVIIK-NH2 (KIVIIK) and Ac-KVIIIK-NH2 (KVIIIK) self-assembled into bilayer twist ribbons and monolayer helical ribbons, respectively. Furthermore, we found that the lateral association of β-sheets can be greatly promoted when the V residue was embedded between I residues. The results clearly demonstrated the significant role of the hydrophobic amino acids sequence in determining the final self-assembling nanostructures, providing a simple and effective way for the construction of self-assemblies with varied morphologies and functions.

Activity of Membrane-Permeabilizing Lpt Peptides.

Herein, we investigated the toxicity and membrane-permeabilizing capabilities of Lpt and Lpt-like peptides, belonging to type I toxin-antitoxin systems carried by plasmid DNA of Lacticaseibacillus strains. These 29 amino acid peptides are predicted to form α-helical structures with a conserved central hydrophobic sequence and differently charged hydrophilic termini. Like Lpt, the expression of Lpt-like in E. coli induced growth arrest, nucleoid condensation, and cell membrane damage, suggesting membrane interaction as the mode of action. The membrane permeabilization activity of both peptides was evaluated by using liposome leakage assays, dynamic light scattering, and CD spectroscopy. Lpt and Lpt-like showed liposome leakage activity, which did not lead to liposome disruption but depended on peptide concentration. Lpt was generally more effective than Lpt-like, probably due to different physical chemical properties. Leakage was significantly reduced in larger liposomes and increased with negatively charged PCPS liposomes, indicating that electrostatic interactions and membrane curvature influence peptide activity. Contrary to most membrane-active peptides, Lpt an Lpt-like progressively lost their α-helical structure upon interaction with liposomes. Our data are inconsistent with the formation of membrane-spanning peptide pores but support a mechanism relying on the transient failure of the membrane permeability barrier possibly through the formation of "lipid pores".

Uncovering a Latent Bioactive Interleukin-6 Glycoform.

A bioinspired semisynthesis of human-interleukin-6 bearing N-glycan at Asn143 (143glycosyl-IL-6) was performed by intentional glycosylation effects and protein folding chemistry for regioselective peptide-backbone activation. 143Glycosyl-IL-6 is a genetically coded cytokine, but isolation was difficult owing to a tiny amount. IL6-polypeptide (1-141-position) with an intentionally inserted cysteine at 142-position was expressed in E. coli. The expressed polypeptide was treated with a chemical folding process to make a specific helices bundle conformation through native two-disulfide bonds (43-49 and 72-82). Utilizing the successfully formed free-142-cysteine, sequential conversions using cyanylation of 142-cysteine, hydrazinolysis, and thioesterification created a long polypeptide (1-141)-thioester. However, the resultant polypeptide-thioester caused considerable aggregation owing to a highly hydrophobic peptide sequence. After the reduction of two-disulfide bonds of polypeptide (1-141)-thioester, an unprecedented hydrophilic N-glycan tag was inserted at the resultant cysteine thiols. The N-glycan tags greatly stabilized polypeptide-thioester. The subsequent native chemical ligation and desulfurization successfully gave a whole 143glycosyl-IL-6 polypeptide (183-amino acids). Removal of four N-glycan tags and immediate one-pot in vitro folding protocol efficiently produced the folded 143glycosyl-IL-6. The folded 143glycosyl-IL-6 exhibited potent cell proliferation activity. The combined studies with molecular dynamics simulation, semisynthesis, and bioassays predict the bioactive conformation of latent 143glycosyl-IL-6.

Uncovering a Latent Bioactive Interleukin‐6 Glycoform

A bioinspired semisynthesis of human‐interleukin‐6 bearing N‐glycan at Asn143 (143glycosyl‐IL‐6) was performed by intentional glycosylation effects and protein folding chemistry for regioselective peptide‐backbone activation. 143Glycosyl‐IL‐6 is a genetically coded cytokine, but isolation was difficult owing to a tiny amount. IL6‐polypeptide (1‐141‐position) with an intentionally inserted cysteine at 142‐position was expressed in E. coli. The expressed polypeptide was treated with a chemical folding process to make a specific helices bundle conformation through native two‐disulfide bonds (43–49 and 72–82). Utilizing the successfully formed free‐142‐cysteine, sequential conversions using cyanation of 142‐cysteine, hydrazinolysis, and thioesterification created a long polypeptide (1–141)‐thioester. However, the resultant polypeptide‐thioester caused considerable aggregation owing to a highly hydrophobic peptide sequence. After the reduction of two‐disulfide bonds of polypeptide (1–141)‐thioester, an unprecedented hydrophilic N‐glycan tag was inserted at the resultant cysteine thiols. The N‐glycan tags greatly stabilized polypeptide‐thioester. The subsequent native chemical ligation and desulfurization successfully gave a whole 143glycosyl‐IL‐6 polypeptide (183‐amino acids). Removal of four N‐glycan tags and immediate one‐pot in vitro folding protocol efficiently produced the folded 143glycosyl‐IL‐6. The folded 143glycosyl‐IL‐6 exhibited potent cell proliferation activity. The combined studies with molecular dynamics simulation, semisynthesis, and bioassays predict the bioactive conformation of latent 143glycosyl‐IL‐6.

AAV-aMTD-Parkin, a therapeutic gene delivery cargo, enhances motor and cognitive functions in Parkinson's and Alzheimer’s diseases

Neurodegenerative disorders, such as Parkinson's disease (PD) and Alzheimer's disease (AD), have a global prevalence and profoundly impact both motor and cognitive functions. Although adeno-associated virus (AAV)-based gene therapy has shown promise, its application for treating central nervous system (CNS) diseases faces several challenges, including effective delivery of AAV vectors across the blood-brain barrier, determining optimal dosages, and achieving targeted distribution. To address these challenges, we have developed a fusion delivery therapeutic cargo called AAV-aMTD-Parkin, which combines a hydrophobic cell-penetrating peptide sequence with the DNA sequences of AAV and Parkin. By employing this fusion delivery platform at lower dosages compared to zolgensma, we have achieved significant enhancements in cell and tissue permeability, while reducing the occurrence of common pathological protein aggregates. Consequently, motor and cognitive functions were restored in animal models of PD and AD. With its dual functionality in addressing PD and AD, AAV-aMTD-Parkin holds immense potential as a novel class of therapeutic biologics for prevalent CNS diseases.

The structural and biophysical basis of substrate binding to the hydrophobic groove in Ubiquilin Sti1 domains.

Ubiquilins are a family of cytosolic proteins that ferry ubiquitinated substrates to the proteasome for degradation. Recent work has demonstrated that Ubiquilins can also act as molecular chaperones, utilizing internal Sti1 domains to directly bind to hydrophobic sequences. Ubiquilins are associated with several neurodegenerative diseases with point mutations in UBQLN2 causing dominant, X-linked Amyotrophic Lateral Sclerosis (ALS). The molecular basis of Ubiquilin chaperone activity and how ALS mutations in the Sti1 domains affect Ubiquilin activity are poorly understood. This study presents the first crystal structure of the Sti1 domain from a fungal Ubiquilin homolog bound to a transmembrane domain (TMD). The structure reveals that two Sti1 domains form a head-to-head dimer, creating a hydrophobic cavity that accommodates two TMDs. Mapping the UBQLN2 sequence onto the structure shows that several ALS mutations are predicted to disrupt the hydrophobic groove. Using a newly developed competitive binding assay, we show that Ubiquilins preferentially bind to hydrophobic substrates with low helical propensity, motifs that are enriched in both substrates and in Ubiquilins. This study provides insights into the molecular and structural basis for Ubiquilin substrate binding, with broad implications for the role of the Sti1 domain in phase separation and ALS.

Potential Impact of Bioactive Peptides from Foods in the Treatment of Hypertension.

High blood pressure (BP) is the main preventable risk factor for cardiovascular diseases (CVDs). Much research is aimed at finding natural alternatives to control or prevent hypertension (HT), since some hypertensive patients do not respond to current pharmacological treatments or show undesirable side effects. Forty relevant articles have been selected from various scientific literature databases. The results reveal that angiotensin-converting enzyme (ACE) inhibition is the most reported mechanism of action of antihypertensive peptides. The active peptides have a great variety of origins. Biopeptides with a molecular weight of <3 kDa, short chain <20 amino acids, and a hydrophobic amino acid sequence at the C- and N-terminus exhibit higher antihypertensive activity. They also show good stability to enzymatic hydrolysis and gastrointestinal digestion, and no toxicity. To determine antihypertensive effectiveness, in vitro and in vivo animal studies are the most frequent developed, with few in silico studies and only one human clinical trial. There is interesting potential for antihypertensive peptides as promising natural candidates for the development of functional foods, nutraceuticals and drugs for preventive or therapeutic treatment of hypertension. The aim of this review is to study the role of food-derived bioactive peptides in HT.

PPIA dictates NRF2 stability to promote lung cancer progression

Nuclear factor erythroid 2-related factor 2 (NRF2) hyperactivation has been established as an oncogenic driver in a variety of human cancers, including non-small cell lung cancer (NSCLC). However, despite massive efforts, no specific therapy is currently available to target NRF2 hyperactivation. Here, we identify peptidylprolyl isomerase A (PPIA) is required for NRF2 protein stability. Ablation of PPIA promotes NRF2 protein degradation and blocks NRF2-driven growth in NSCLC cells. Mechanistically, PPIA physically binds to NRF2 and blocks the access of ubiquitin/Kelch Like ECH Associated Protein 1 (KEAP1) to NRF2, thus preventing ubiquitin-mediated degradation. Our X-ray co-crystal structure reveals that PPIA directly interacts with a NRF2 interdomain linker via a trans-proline 174-harboring hydrophobic sequence. We further demonstrate that an FDA-approved drug, cyclosporin A (CsA), impairs the interaction of NRF2 with PPIA, inducing NRF2 ubiquitination and degradation. Interestingly, CsA interrupts glutamine metabolism mediated by the NRF2/KLF5/SLC1A5 pathway, consequently suppressing the growth of NRF2-hyperactivated NSCLC cells. CsA and a glutaminase inhibitor combination therapy significantly retard tumor progression in NSCLC patient-derived xenograft (PDX) models with NRF2 hyperactivation. Our study demonstrates that targeting NRF2 protein stability is an actionable therapeutic approach to treat NRF2-hyperactivated NSCLC.

Exploring a Solvent Dependent Strategy to Control Self-Assembling Behavior and Cellular Interaction in Laminin-Mimetic Short Peptide based Supramolecular Hydrogels.

Self-assembled hydrogels, fabricated through diverse non-covalent interactions, have been extensively studied in regenerative medicines. Inspired from bioactive functional motifs of ECM protein, short peptide sequences have shown remarkable abilities to replicate the intrinsic features of the natural extracellular milieu. In this direction, we have fabricated two short hydrophobic bioactive sequences derived from the laminin protein i. e., IKVAV and YIGSR. Based on the substantial hydrophobicity of these peptides, we selected a co-solvent approach as a suitable gelation technique that included different concentrations of DMSO as an organic phase along with an aqueous solution containing 0.1 % TFA. These hydrophobic laminin-based bioactive peptides with limited solubility in aqueous physiological environment showed significantly enhanced solubility with higher DMSO content in water. The enhanced solubility resulted in extensive intermolecular interactions that led to the formation of hydrogels with a higher-order entangled network along with improved mechanical properties. Interestingly, by simply modulating DMSO content, highly tunable gels were accessed in the same gelator domain that displayed differential physicochemical properties. Further, the cellular studies substantiated the potential of these laminin-derived hydrogels in enhancing cell-matrix interactions, thereby reinforcing their applications in tissue engineering.

Substrate recognition mechanism of the endoplasmic reticulum-associated ubiquitin ligase Doa10

Doa10 (MARCHF6 in metazoans) is a large polytopic membrane-embedded E3 ubiquitin ligase in the endoplasmic reticulum (ER) that plays an important role in quality control of cytosolic and ER proteins. Although Doa10 is highly conserved across eukaryotes, it is not understood how Doa10 recognizes its substrates. Here, we define the substrate recognition mechanism of Doa10 by structural and functional analyses on Saccharomyces cerevisiae Doa10 and its model substrates. Cryo-EM analysis shows that Doa10 has unusual architecture with a large lipid-filled central cavity, and its conserved middle domain forms an additional water-filled lateral tunnel open to the cytosol. Our biochemical data and molecular dynamics simulations suggest that the entrance of the substrate’s degron peptide into the lateral tunnel is required for efficient polyubiquitination. The N- and C-terminal membrane domains of Doa10 seem to form fence-like features to restrict polyubiquitination to those proteins that can access the central cavity and lateral tunnel. Our study reveals how extended hydrophobic sequences at the termini of substrate proteins are recognized by Doa10 as a signal for quality control.

Effects of hydrophobic sequence patterns on disordered protein conformational ensembles

Effects of hydrophobic sequence patterns on disordered protein conformational ensembles

Unique Behavior of Bacterially Expressed Rat Carnitine Palmitoyltransferase 2 and Its Catalytic Activity.

Mammalian type 2 carnitine parmitoyltransferase (EC 2.3.1.21), abbreviated as CPT2, is an enzyme involved in the translocation of fatty acid into the mitochondrial matrix space, and catalyzes the reaction acylcarnitine + CoA = acyl-CoA + carnitine. When rat CPT2 was expressed in Escherichia coli, its behavior was dependent on the presence or absence of i) its mitochondrial localization sequence and ii) a short amino acid sequence thought to anchor it to the mitochondrial inner membrane: CPT2 containing both sequences behaved as a hydrophobic protein, while recombinant CPT2 lacking both regions behaved as a water soluble protein; if only one region was present, the resultant proteins were observed in both fractions. Because relatively few protein species could be obtained from bacterial lysates as insoluble pellets under the experimental conditions used, selective enrichment of recombinant CPT2 protein containing both hydrophobic sequences was easily achieved. Furthermore, when CPT2 enriched in insoluble fraction was resuspended in an appropriate medium, it showed catalytic activity typical of CPT2: it was completely suppressed by the CPT2 inhibitor, ST1326, but not by the CPT1 inhibitor, malonyl-CoA. Therefore, we conclude that the bacterial expression system is an effective tool for characterization studies of mammalian CPT2.

Drug Encapsulation via Peptide-Based Polyelectrolyte Complexes.

Peptide-based polyelectrolyte complexes are biocompatible materials that can encapsulate molecules with different polarities due to their ability to be precisely designed. Here we use UV-Vis spectroscopy, fluorescence microscopy, and infrared spectroscopy to investigate the encapsulation of model drugs, doxorubicin (DOX) and methylene blue (MB) using a series of rationally designed polypeptides. For both drugs, we find an overall higher encapsulation efficiency with sequences that have higher charge density, highlighting the importance of ionic interactions between the small molecules and the peptides. However, comparing molecules with the same charge density, illustrated that the most hydrophobic sequence pairs had the highest encapsulation of both DOX and MB molecules. The phase behavior and stability of DOX-containing complexes did not change compared to the complexes without drugs. However, MB encapsulation caused changes in the stabilities of the complexes. The sequence pair with the highest charge density and hydrophobicity had the most dramatic increase in stability, which coincided with a phase change from liquid to solid. This study illustrates how multiple types of molecular interactions are required for efficient encapsulation of poorly soluble drugs and provides insights into the molecular design of delivery carriers.

On the role of nucleotides and lipids in the polymerization of the actin homolog MreB from a Gram-positive bacterium.

In vivo, bacterial actin MreB assembles into dynamic membrane-associated filamentous structures that exhibit circumferential motion around the cell. Current knowledge of MreB biochemical and polymerization properties in vitro remains limited and is mostly based on MreB proteins from Gram-negative species. In this study, we report the first observation of organized protofilaments by electron microscopy and the first 3D-structure of MreB from a Gram-positive bacterium. We show that Geobacillus stearothermophilus MreB forms straight pairs of protofilaments on lipid surfaces in the presence of ATP or GTP, but not in the presence of ADP, GDP or non-hydrolysable ATP analogs. We demonstrate that membrane anchoring is mediated by two spatially close short hydrophobic sequences while electrostatic interactions also contribute to lipid binding, and show that the population of membrane-bound protofilament doublets is in steady-state. In solution, protofilament doublets were not detected in any condition tested. Instead, MreB formed large sheets regardless of the bound nucleotide, albeit at a higher critical concentration. Altogether, our results indicate that both lipids and ATP are facilitators of MreB polymerization, and are consistent with a dual effect of ATP hydrolysis, in promoting both membrane binding and filaments assembly/disassembly.

Masking the transmembrane region of the amyloid β precursor protein as a safe means to lower amyloid β production.

Reducing brain levels of both soluble and insoluble forms of amyloid beta (Aβ) remains the primary goal of most therapies that target Alzheimer's disease (AD). However, no treatment has so far resulted in patient benefit, and clinical trials of the most promising drug candidates have generally failed due to significant adverse effects. This highlights the need for safer and more selective ways to target and modulate Aβ biogenesis. Peptide technology has advanced to allow reliable synthesis, purification, and delivery of once-challenging hydrophobic sequences. This is opening up new routes to target membrane processes associated with disease. Here we deploy a combination of atomic detail molecular dynamics (MD) simulations, living-cell Förster resonance energy transfer (FRET), and in vitro assays to elucidate the atomic-detail dynamics, molecular mechanisms, and cellular activity and selectivity of a membrane-active peptide that targets the Aβ precursor protein (APP). We demonstrate that Aβ biogenesis can be downregulated selectively using an APP occlusion peptide (APPOP). APPOP inhibits Aβ production in a dose-dependent manner, with a mean inhibitory concentration (IC50) of 450nM toward exogenous APP and 50nM toward endogenous APP in primary rat cortical neuronal cultures. APPOP does not impact the γ-secretase cleavage of Notch-1, or exhibit toxicity toward cultured primary rat neurons, suggesting that it selectively shields APP from proteolysis. Drugs targeting AD need to be given early and for very long periods to prevent the onset of clinical symptoms. This necessitates being able to target Aβ production precisely and without affecting the activity of key cellular enzymes such as γ-secretase for other substrates. Peptides offer a powerful way for targeting key pathways precisely, thereby reducing the risk of adverse effects. Here we show that protecting APP from proteolytic processing offers a promising route to safely and specifically lower Aβ burden. In particular, we show that the amyloid pathway can be targeted directly and specificically. This reduces the risk of off-target effects and paves the way for a safe prophylactic treatment.

Prediction of antimicrobial activity of a food peptide and evaluation of its effectiveness in vitro

Food antimicrobial peptides are increasingly relevant in the treatment of bacterial infections and have a number of advantages in comparison with drugs: slower emergence of resistance in bacterial strains, high activity against antibiotic films and immunomodulatory properties. The physico-chemical properties causing antimicrobial properties include: cationic charge, hydrophobicity, molecular weight and amino acid sequence. Promising sources of antimicrobial peptides are milk proteins, in particular, cow colostrum proteins. The aim of the work is to extract a peptide from the pepsin hydrolysate of cow colostrum, predict its antimicrobial activity using a bioinformatic approach and confirm its effectiveness in vitro. The molecular mass distribution of the peptide was evaluated by mass spectrometric method. The analysis of mass spectra was carried out using the Mascot program, the Peptide Fingerprint option – using the Protein NCBI database. Microsequencing was performed using a MiSeq sequencer. Modeling of the spatial structure of the isolated peptide was carried out using the Schrodinger Maestro molecular modeling program. The antimicrobial activity of the peptide was studied by the disco-diffusion method on gram-positive and gram-negative bacteria. The peptide has been isolated from the pepsin hydrolysate of cow colostrum, which is absent in the known proteomic bases Protein NCBI and AVPdb and, accordingly, its biological activity and functions have not been studied. The resulting peptide belongs to linear alpha-helical peptides consists of 11 amino acid sequences ANRKLRANKSR with a molecular weight of 8.2 kDa, an isoelectric point at 12.79, a charge of +5 (cationic), hydrophilicity (hydrophobicity) +20.84 Kcal*mol-1. As a result of in vitro studies, it was found that the isolated peptide has antimicrobial activity against E. coli ATCC 25922 and B. subtilis and antimicrobial action against C. albicans.

Applicability of supercritical fluid chromatography for oligonucleotide analysis: A proof-of-concept study

We evaluated the suitability of supercritical fluid chromatography (SFC) for oligonucleotide analysis using 4-mer oligonucleotides with various phosphorothioate (PS) contents as model compounds. Column screening showed that the diol-modified column was able to separate sequences with different PS contents. Optimization of the column body and additives allowed us to analyze polar oligonucleotides using SFC. Various sequences were also analyzed using the optimized method. A good peak shape was obtained when the guanine plus cytosine content of the analyte was two or less in the 4-mer oligonucleotides. Furthermore, we found that the retention times of the selected sequences were positively correlated with polar surface areas, indicating that oligonucleotides interact with polar stationary phases. In contrast, more hydrophobic full PS sequences were retained more strongly in the diol column than the full phosphodiester (PO) sequences. This suggests that the diol column has unique selectivity for PO and PS linkages. These results indicate that SFC is potentially applicable to oligonucleotide analysis with a separation mechanism that is different from that of ion-pair reversed-phase liquid chromatography.

Determining the Sequence Dependency of Self-Assembly of Elastin-Like Peptides Using Short Peptide Analogues with Shuffled Repetitive Sequences.

Synthetic elastin-like peptides (ELPs) that possess characteristic tropoelastin-derived hydrophobic repetitive sequences, such as (VPGVG)n, exhibit thermoresponsive reversible self-assembly. Although their thermoresponsive properties have been well-studied, the sequence-dependent and structural requirements for self-assembly remain ambiguous. In particular, it is still unclear whether the amino acid sequences derived from tropoelastin are necessary for self-assembly. In this study, 11 sequence-shuffled ELP analogues based on (FPGVG)5, which is a previously developed short ELP (sELP), were designed to elucidate the sequence-dependent and structural requirements for their self-assembly. Among them, eight shuffled peptides exhibited self-assembling properties, whereas the other three peptides were difficult to dissolve in water. Structural analyses revealed that the structural characteristics of the three insoluble peptides were different from those of their thermoresponsive analogues. Furthermore, the secondary structures of the peptide analogues possessing the self-assembly abilities were different from each other. These results suggest that the potential for self-assembly and water solubility of sELPs depend on the primary structure in each repeated unit. Moreover, several shuffled analogues exhibited more potent self-assembling properties than the original (FPGVG)5, indicating that shorter ELPs can be obtained using their novel motifs as repetitive units. We also observed that the presence of Pro-Gly sequence in the repeating units was advantageous in terms of peptide solubility. Although further analysis will be necessary to elucidate the molecular mechanism underlying the self-assembly of these sELPs, this study provides insights into the relationship between the amino acid sequence and the self-assembling ability of the peptides for developing new sELPs for various applications.

IGL CDR3 Hydropathy and Antigen Chemical Complementarity Associated with Greater Disease-Free Survival in Lung Adenocarcinoma: Implications for Gender Disparities.

With lung cancer remaining a challenging disease, new approaches to biomarker discovery and therapy development are needed. Recent immunogenomics, adaptive immune receptor approaches have indicated that it is very likely that B cells play an important role in mediating better overall outcomes. As such, we assessed physicochemical features of lung adenocarcinoma resident IGL complementarity determining region-3 (CDR3) amino acid (AA) sequences and determined that hydrophobic CDR3 AA sequences were associated with a better disease-free survival (DFS) probability. Further, using a recently developed chemical complementarity scoring algorithm particularly suitable for the evaluation of large patient datasets, we determined that IGL CDR3 chemical complementarity with certain cancer testis antigens was associated with better DFS. Chemical complementarity scores for IGL CDR3-MAGEC1 represented a gender bias, with an overrepresentation of males among the higher IGL-CDR3-CTA complementarity scores that were in turn associated with better DFS (logrank p < 0.065). Overall, this study pointed towards potential biomarkers for prognoses that, in some cases are likely gender-specific; and towards biomarkers for guiding therapy, e.g., IGL-based opportunities for antigen targeting in the lung cancer setting.