This work focuses on how natural polyamines (PAs), such as putrescine (PUT), spermidine (SPD), and spermine (SPM), interact with hen egg white lysozyme (HEWL) and how these interactions alter its conformational stability and dynamics at pH 4.4. Analysis of the effects of PAs on the equilibrium thermodynamic parameters, along with molecular dynamics (MD) simulations of HEWL, revealed that these PAs reduce HEWL's structural stability and increase its conformational fluctuations in the following order: SPM > SPD > PUT. This suggests that the number of amino groups in the PAs plays a critical role in altering the protein's stability and dynamics. Both the experimental and MD simulation studies of HEWL yielded positive preferential interaction coefficients and negative preferential hydration parameters for PAs, following the same order: SPM > SPD > PUT. This finding reveals that the preferential binding of PAs to HEWL, along with alterations in the energetics of the hydration layer, typically alters the protein's conformational stability and dynamics, with a more pronounced effect from PAs containing a greater number of amino groups. Additionally, the analysis of the impact of PAs on enthalpy-entropy plots and unfolding free energy-temperature profiles of HEWL reveals that the binding interactions of PAs to HEWL are predominantly of enthalpic nature. Furthermore, the examination of PA's effects on the urea-concentration-dependent melting temperature of HEWL reveals that these PAs have an additive effect on urea's denaturing ability, further reducing the thermal stability of HEWL in the following order: SPM > SPD > PUT. Lastly, the analysis of the effects of PAs on the fluorescence lifetime of HEWL reveals that PAs shorten the average fluorescence of HEWL, suggesting that these PAs form excited-state interactions with HEWL.

Integrated physiological and transcriptomic analyses reveal the role of polyamines in blueberry fruit coloration.

New chemotherapeutic strategies against mesenchymal triple-negative breast cancer: A deeper look at the molecular level.

Polyamines (PAs) play critical roles in plant growth, somatic embryogenesis (SE), etc. Previous studies have demonstrated that exogenous PAs could promote SE in plants. However, the effects of PAs on Ginkgo biloba L. SE are still unknown, especially in the switch from the initial callus (IC) to the embryogenic callus (EC) stage or to the globular embryo (GE) stage. This work identified 34 genes involved in PAs metabolism in G. biloba using genome-wide analyses. These genes were clustered into six families and found to be unevenly distributed across 11 of the 12 chromosomes on the plant. These families contain 539 cis-acting elements that mainly respond to phytohormones, abiotic stress, meristem expression, etc. RNAseq analysis revealed that the expression of GbADC2, GbSAMDC2, GbSPMS1, GbCuAO1 and 3, and GbPAO3, 8, 6 and 13 genes in G. biloba were higher in the GE stage than in the IC stage. In addition, 1.0 mg·L−1 spermine (Spm3) could promote the conversion of IC to EC, while 0.01 mg·L−1 putrescine (Put1) could facilitate the transition from IC to EC and then to GE. During the conversion of IC to EC or to GE, higher levels of abscisic acid (ABA), superoxide dismutase (SOD), and peroxidase (POD) and lower levels of indole-3-acetic acid (IAA), gibberellin (GA3), and zeatin (ZT) were observed; concurrently, the H2O2 level was also observed to be high. Gene expressions of GbSPMS2, GbCuAO3, and GbPAO6 and 8 were upregulated, while GbADC2 expression was downregulated in the EC or GE stages under Spm3- or Put1- treatment. These results illustrate that exogenous PAs might alter the levels of the endogenous polyamine pool and lead to H2O2 production, which caused a certain oxidative stress. However, SOD and POD balanced H2O2 production and maintained homeostasis. The PAs–H2O2–ABA module might coordinate the regulation of early in of G. biloba. These relations were discussed in this work. These findings provide a foundation for comprehending the roles of PAs gene families in the key nodes of early SE in G. biloba.

Triple-Negative Breast Cancer Versus Non-Triple-Negative Breast Cancer: The Impact of Pd and Pt Complexes on Basal-Like Triple-Negative Breast Cancer.

Interplay of ethylene and polyamines in plant growth, development and stress responses

Resistance to antibiotic treatments continues to be a significant health challenge and necessitates investigating novel antibacterial targets including noncoding regulatory RNA. The antiterminator RNA element of the T-box riboswitch is one such novel target. In this report, we investigated a spatially dispersed polycationic pharmacophore model for targeting the T-box antiterminator RNA. Decapeptides were designed based on a known alkyl polyamine agonist of the T-box riboswitch. Antiterminator model RNA binding was assessed using native mass spectrometry and modulation of T-box riboswitch function determined using a previously validated fluorescence-based assay. One peptide was identified that formed a complex with antiterminator model RNA and selectively inhibited T-box riboswitch transcription readthrough (both with and without tRNA induction). The inhibitory activity of this polycationic peptide, which was designed to mimic biogenic polyamines, has implications for future drug discovery efforts targeting the T-box riboswitch and other medicinally important noncoding regulatory RNA.

Putrescine and cadaverine are biogenic polyamines that result from the breakdown of the amino acids ornithine and lysine, respectively, and, as a rule, under participation of bacteria. It was revealed that putrescine and cadaverine are able to influence functional activity of innate immune cells at the sites of inflammation. The potential of these compounds to interact with immune cells by changing their activity, including synthetic abilities, causes interest in studying the production of immunoglobulins (Ig) by plasma cells in the presence of polyamines, especially, within inflamed area. The aim of research was to evaluate the effect of cadaverine and putrescine on the production of IgG in cultured mononuclear leukocytes of patients suffering with maxillofacial phlegmon. Leukocytes were obtained from 13 patients with maxillofacial phlegmon and 10 healthy donors. After washing the cells, they were brought to the wells, where B cell mitogen (PWM) and polyamines were added at concentrations of 5, 25, 50, 75 and 100 mmol/L. An equal volume of nutrient medium was added to the control wells instead of polyamines. At the end of cultivation, a supernatant was collected, where the concentrations of immunoglobulins G (IgG) were determined using the enzyme immunoassay method. In the absence of polyamines, higher IgG production by mononuclear cells of patients with acute purulent process (27.6±2.2 IU per 1 g of protein) was revealed compared with healthy donors (13.6±1.5 IU per 1 g of protein; p = 0.002) showing a positive correlation. When culturing patients’ lymphocytes in the presence of polyamines, we have found that cadaverine at all concentrations did not significantly change IgG production in mononuclear culture. When using putrescine, it was found that this metabolite in the culture of mononuclears in dose-dependent manner reduces their IgG production. Putrescine and cadaverine have a multidirectional effect on IgG production in the culture of mononuclear leukocytes of patients with facial phlegmon, due to their role in inflammatory events.

Background: Gallstones or cholelithiasis are a major public health issue, which often remain asymptomatic, although they can sometimes cause discomfort by obstructing the digestive tract. Spermidine (SPD) and Spermine (SPE) are two polyamines (PAs) that regulate the growth of hepatocytes in the liver. The PAs play two functions in preserving cellular oxidative equilibrium by generating reactive oxygen species (ROS) and providing protection against free radical damage when serving as an enzyme substrate. Therefore, levels and metabolism of PA serve as significant markers of neoplastic alterations in the liver.Methods: Gallstone patients from multiple internal medicine hospitals were surveyed, and samples were taken and evaluated from them. Similarly, samples from healthy individuals were also taken. Under regular laboratory circumstances, the patient samples were characterized using biochemical tests, and their data was documented.Result: The levels of polyamines (PAs) and the common oxidative stress (OS) biomarker malondialdehyde (MDA) were determined. The main liver function tests and lipid profile levels showed no significant differences between the two studied groups. Whereas malondialdehyde (MDA), SPE, and SPD levels were significantly higher in patients than in the control group.Conclusion: The results of the study led to an association between polyamine levels and gallstone disease. An increase in PA levels was observed in cholelithiasis patients. It is concluded that PAs are associated with cholelithiasis and may be considered as potential predictors of this disease.Keywords:Cholelithiasis, Spermine, Spermidine, Malondialdehyde, Oxidative stress

Chloroplasts are the energy factories of photosynthetic life. The energy and the plant biomass of the planet depend on the activity of chloroplasts. Their efficiency results from a delicate balance between membrane organization, metabolic regulation and the maintenance of protein homeostasis. Among the molecular factors that support chloroplast structure and function, polyamines (PAs) and transglutaminases (TGases) have emerged as key regulators of photosynthetic performance and stress tolerance. PAs stabilize thylakoid membranes, influence proton-motive force partitioning, modulate chlorophyll biosynthesis and protect the photosynthetic apparatus from oxidative damage, thereby contributing to increased photoprotection and delayed senescence. TGases, particularly the plastid-localized isoforms, catalyze the covalent conjugation of PAs to stromal and thylakoid proteins, including RuBisCo and light-harvesting complexes (LHC). These reactions affect protein stability, supramolecular assembly, and the dynamic remodeling of LHC. Light-, pH- and redox-dependent activation of TGases links PA dependent protein modification to the regulation of photosynthetic efficiency and stress responses. This review integrates biochemical, structural and physiological evidence to highlight how PAs and TGases operate at the interface of light-to-chemical energy conversion. Both are involved in membrane organisation and maintaining protein quality. Understanding this molecular network provides new perspectives for improving plant performance, enhancing tolerance to abiotic stress and sustaining biomass production, notably that of agriculture interest, under changing environmental conditions.

Ornithine decarboxylase (ODC) functions as the rate-limiting enzyme in the polyamine (PA) biosynthetic pathway. It catalyzes the decarboxylation of L-ornithine to produce putrescine, thereby initiating the biosynthesis of polyamines. Polyamines are a class of widely distributed polycationic aliphatic compounds in living organisms, including putrescine, spermidine, and spermine. They serve not only as critical regulators of cell growth, proliferation, and differentiation, but also as important signaling molecules involved in plant responses to environmental stress and key precursors in the biosynthesis of diverse secondary metabolites. Focusing on recent advances in plant ODC research, this review summarizes the characteristics and evolutionary relationships of the ODC gene family, the biochemical properties and catalytic mechanism of the enzyme, and its multiple physiological roles in growth, development, secondary metabolism, and stress adaptation. Furthermore, we discuss the complex regulatory mechanisms governing ODC activity at both transcriptional and post-translational levels, with a critical gap in understanding the post-translational regulation of ODC in plants, particularly the mechanisms governing its degradation. Unlike in animals, where antizymes mediate ODC degradation, functional analogs of antizymes have not yet been identified in plants, leaving the degradation pathway largely unexplored. Finally, we review the applications of plant genetic modification targeting ODC in enhancing the production of valuable secondary metabolites in medicinal plants and improving stress tolerance in crops, along with perspectives on future research directions. This review illustrates the diversity of ODC functions and the complexity of its regulatory mechanisms in plant growth, development, stress responses, and secondary metabolism. It also provides a theoretical foundation and insights for exploring ODC as a target for plant genetic modification, which is promising for improving the economic traits and stress resistance of horticultural plants.

The mechanisms by which polyamines regulate wheat grain filling under drought stress conditions.

ABSTRACT Rapid climate change greatly decreases global wheat yield, making further breeding of it a necessity to fulfil the also increasing dietary need of the population. For this, a wild relative of wheat, the goatgrass Aegilops biuncialis Vis. 382 ( Ae.b. 382) is a suitable candidate, in light of its better drought tolerance compared to wheat. Polyamines (PAs) are low molecular weight defensive molecules with a prominent role in abiotic stress reactions. This study investigated the role of polyamines in the adaptive response of Ae.b. 382 to PEG‐induced osmotic stress by investigating the effects of exogenous polyamines and their biosynthesis inhibitors on root architecture, polyamine levels and related gene expression profiles. The two‐day‐long 33 mM PEG treatment induced strong physiological changes, resulting in alterations in root robusticity. The simultaneous application of PA inhibitors strongly reduced root fresh weight (FW), length and surface, disrupting the process of adaptive thickening. However, additions of exogenous spermidine, spermine or a combined PA mix were able to counteract the negative effects of the inhibitors or activate defensive measures. The results on polyamine content and gene expressional profiling confirmed our hypothesis that polyamines are one of the key compounds in drought stress adaptation responses of Ae.b. 382. Also, the complex, bilateral regulation of polyamine metabolism and transport between root and shoot is important for fine‐tuning of balanced defence and signalling mechanisms.

Biocontrol efficacy and mechanism of Bacillus subtilis PL5 against root rot of sweet potato: Insights into antifungal activity and metabolite function.

Hybrid machine learning models for predicting density, dynamic viscosity, and speed of sound in aliphatic biogenic polyamines

Climate change in Spain is altering the optimal conditions for producing high-quality 'Mollar de Elche' pomegranate fruit, due to reduced colour development in husk and arils. In addition, the pomegranate requires storage above 7-10 °C, depending on cultivar, to preserve its quality because it is susceptible to chilling injury (CI) damage at lower temperatures. In this study, the effect of preharvest application of 0.01 and 0.1 mmol L-1 spermidine (SPD) and putrescine (PUT) on crop yield and fruit quality at harvest was evaluated in two consecutive years, 2022 and 2023, and during cold storage at chilling temperature in fruit for the 2023 trial. Results showed that SPD and PUT, at 0.01 and 0.1 mmol L-1, significantly increased crop yield and improved fruit quality parameters at harvest in the experiments carried out in 2022 and 2023. The application of polyamines (PAs) effectively alleviated CI after 30, 60 and 90 days of storage at 2 °C (85-90% RH) plus 2 days at 20 °C (55-60% RH) by reducing electrolyte leakage, malondialdehyde accumulation and peel browning. PAs also preserved fruit firmness and titratable acidity and decreased respiration rate and weight loss. In addition, the ripening index was significantly lower in PA-treated fruit compared to controls during the whole storage period. Finally, PAs increased total phenolic content in arils, especially anthocyanins, which intensified aril red colour. Notably, SPD at 0.01 mmol L-1 was the most effective treatment in improving crop yield, red colour of husk and arils and anthocyanin content in arils with strong effects also in reducing CI symptoms. The findings demonstrate the potential of PAs, especially SPD at 0.01 mmol L-1, as an effective and sustainable tool to improve crop yield, mitigate CI and preserve the quality of 'Mollar de Elche' pomegranate fruit during cold storage. Thus, PA treatments would lead to an increase in growers' income and health benefits for consumers, due to the enhanced bioactive compound content. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The development of sensors capable of selectively detecting polyamines in aqueous environments is crucial for early and noninvasive disease diagnostics. These aliphatic cations participate in fundamental cellular processes, and their dysregulation has been linked to several cancers and neurodegenerative disorders. Although conventional detection methods, such as chromatography and mass spectrometry, offer excellent sensitivity, their complexity, cost, and limited portability restrict their use in rapid or point-of-care testing. This work presents a colorimetric nanosensor based on gold nanoparticles (AuNPs) functionalized with a p-tert-butyl-calix[5]arene derivative (Calix[5]), a supramolecular receptor with selectivity for primary alkylammonium ions imparted by intracavity host-guest complexation. The molecular recognition event induces interparticle bridging, triggering nanoparticle aggregation that manifests as a visible color change of the suspension. The system exhibits remarkable chain-length-dependent selectivity: long polyammonium chains, such as 1,12-dodecanediammonium and the biogenic polyamine spermine, induce rapid (<5min) nanoparticle aggregation, resulting in a distinct plasmonic shift. In contrast, shorter analogues (spermidine, 1,6-hexadiammonium) show negligible responses. These findings demonstrate a simple, rapid, and cost-effective approach for the selective sensing of structurally defined polyamines, with potential applications in noninvasive biomarker monitoring.

The study investigated the biochemical and bioactive profiles of three wild inedible mushrooms— Cortinarius trivialis , Mycena pura , and Mycena rosea —focusing on polyamine (PA) content, polyphenols, proteins, antioxidants, and acetylcholinesterase (AChE) inhibition. Among the three PAs measured (putrescine (PUT), spermidine (SPD), and spermine (SPM)), C. trivialis showed the highest levels of PUT and SPD, distinguishing it metabolically. In contrast, M. pura and M. rosea had lower PA levels but were richer in proteins and phenolics. Notably, M. rosea had the highest protein content (42.46%), while M. pura exhibited the greatest total phenolic and flavonoid content, correlating with its strong antioxidant activity across multiple assays. M. rosea demonstrated selective ABTS radical scavenging and the most potent AChE inhibition (93.24 ± 7.90%), suggesting potential neuroprotective benefits. Phenolic profiling revealed species‐specific compounds: C. trivialis was rich in p ‐hydroxybenzoic and quinic acids, while Mycena species contained protocatechuic acid and trace flavonoids. Principal component analysis underscored distinct biochemical clustering: M. pura with antioxidant‐rich phenolics, M. rosea with neuroprotective SPD content, and C. trivialis with elevated PUT. This is the first report detailing PA composition and AChE inhibition in these mushrooms, highlighting their unique and complementary antioxidant and neuroprotective potential.

Uncontrolled bleeding in trauma and surgical settings requires rapid, minimally invasive materials that can effectively stop bleeding and provide durable wound sealing. Here, we introduce an injectable, pH-responsive amphiphilic hydrogel designed for quick hemostasis, strong wet-tissue adhesion, and controlled therapeutic release. The hydrogel is prepared via a mild nucleophilic substitution reaction between tertiary amines of Poly(2-(dimethylamino)ethyl methacrylate (PDMA) and gallic acidfunctionalized branched polyethyleneimine PEI(GA), using chloride-terminated Pluronic F-127 (Cl-Plu-Cl) as a crosslinker. The shear-thinning, uniform prepolymer allows for consistent laparoscopic delivery and rapidly gels in situ (∼54 seconds) across a physiological pH range (5.07.4). In vitro and in vivo tests, including a mouse liver hemorrhage model, showed a 61% reduction in blood loss, comparable to Truseal (∼63%), while providing better injectability, biocompatibility, flexibility, and adjustable degradation and gelation properties. The (Cl-Plu-Cl/PDMA/PEI(GA)) hydrogel demonstrates strong adhesion strength (∼47 kPa) and withstands burst pressures up to 220 mmHg, exceeding typical arterial blood pressure. Sustained, pH-responsive release of amoxicillin (∼60% at pH 7.4 and ∼98% at pH 5.0 over 80 hours) displayed antibacterial activity against Staphylococcus aureus and MRSA. Alamar Blue and Live/Dead assays confirmed over 90% cell viability, and the gradual in vitro degradation over three weeks indicates safe resorption and potential for clinical use.

This study presents a data-driven framework for predicting key thermophysical properties including dynamic viscosity, speed of sound, and density of aqueous solutions containing aliphatic biogenic polyamines (ABPs), which are of growing importance in biochemical and industrial applications. A total of 198 experimentally measured data points were used to train and validate five advanced machine learning models: K-Nearest Neighbors (KNN), Ensemble Learning (EL), Convolutional Neural Networks (CNN), Adaptive Boosting (AdaBoost), and Multi-Layer Perceptron Artificial Neural Networks (MLP-ANN). Hyperparameter optimization was conducted using the Coupled Simulated Annealing (CSA) algorithm. The study focused on three ABPs including Putrescine dihydrochloride (PUT), Cadaverine dihydrochloride (CAD), and Spermine tetrahydrochloride (SPER) across a range of molar masses, concentrations, and temperatures. Sensitivity analysis using the Monte Carlo method revealed ABP type and molar mass as dominant factors influencing the target properties. Among the models, MLP-ANN demonstrated the highest predictive accuracy for density and viscosity, while EL performed best for speed of sound. The results confirm the potential of machine learning as a reliable, efficient, and cost-effective alternative to conventional experimental approaches for modeling complex solution behavior.