The aim of this study was to investigate the effects and underlying mechanisms of l-arginine (Arg) and l-lysine (Lys) as phosphate-free tenderizing agents on the quality improvement of beef round, with the goal of providing a safe and effective alternative to traditional phosphates. Tenderizing efficacy was evaluated by systematically measuring shear force, pH, water-holding capacity, and water distribution. The tenderization mechanisms were elucidated through analyses of myofibrillar protein characteristics, endogenous protease activity, protein secondary structure, and microstructure. Compared with the control group, treatment with Arg and Lys significantly reduced shear force (by 74.67% and 76.36%, respectively), increased pH, improved water-holding capacity, and enhanced sensory attributes, including texture, juiciness, tenderness, and flavor. Mechanistic studies revealed that both amino acids promoted tenderness through multiple synergistic pathways, including inducing a structural transition of myofibrillar proteins from ordered α-helix to disordered β-sheet and random coil, activating caspase-3 and cathepsin B, strongly increasing the myofibrillar fragmentation index (MFI) and protein solubility, and promoting the conversion of free water to an immobilized state. Scanning electron microscopy (SEM) further confirmed that the treatments enlarged inter-myofibrillar gaps significantly and promoted structural loosening. Both Arg and Lys are effective phosphate-free tenderizing agents. Lys was more effective in elevating pH, promoting myofibrillar dissociation, and activating cathepsin B, indicating greater application potential. This study provides a novel technological strategy for the value-added processing of beef round and a theoretical basis for the development of Arg- and Lys-based phosphate-free tenderizers. © 2026 Society of Chemical Industry.

Physicochemical and functional properties of high-protein flour for lentil-rice meat analog nuggets.

Characterization and comparison of the structure and antioxidant activity of queen bee larvae (Apis mellifera) hydrolysates processed with different proteases.

Bias voltage enhances extracellular polymeric substances-mediated extracellular electron transport.

Chitosan/hydroxypropyl guar gum/fucoidan composite-stabilized Pickering emulsions for enhanced surimi gel quality.

Effects of pre-conditioning combined with innovative grilling processes on myofibrillar protein microstructure, volatilome shifting, and heterocyclic amine formation in duck meat.

Ultrasound-induced cavitation effects on microbial load, colloidal structure and techno-functional properties of Moroccan camel milk.

Dehydration-induced changes in physical and volatile characteristics of house cricket (Acheta domesticus) powder

The impact of protein secondary structure on coagulation activity in model water: efficacy of natural coagulants from green lentil seeds in turbidity removal

Binding characteristics and mechanisms underlying the enhanced stability of anthocyanins by proteins screened with molecular docking.

Microalgae powder alters protein conformation and gluten-starch microstructure to attenuate starch digestibility in steamed bread.

Malignant peripheral nerve sheath tumors (MPNST) exhibit pronounced alterations in lipid organization that contribute to tumor aggressiveness and resistance to radiotherapy. In this work, we combine atomic force microscopy-infrared spectroscopy (AFM-IR) and fluorescence imaging to investigate nanoscale lipid remodeling in Schwann and MPNST cells exposed to cannabidiol (CBD) and ionizing radiation, while introducing a new semiquantitative strategy for AFM-IR image analysis. Conventional band-based AFM-IR spectroscopy was first employed to identify characteristic biochemical signatures in the perinuclear region, revealing CBD- and irradiation-dependent modifications of phospholipids (1260 cm-1-1240 cm-1) and cholesteryl esters, monitored via the ester carbonyl band at 1740 cm-1. These spectral changes provided a biochemical basis for further nanoscale analysis, but were restricted to intensity-based interpretation. To overcome this limitation, we introduce, for the first time, a pixel-based AFM-IR semi-quantification framework that converts nanospectroscopic maps into statistically robust biochemical metrics. High-resolution AFM-IR images were processed to extract pixel-resolved ester-specific signals, enabling semi-quantitative determination of both the average cholesteryl ester signal intensity and the nanoscale surface area occupied by ester-rich domains. Statistical evaluation using ANOVA with Tukey's post-hoc test allowed direct comparison of lipid redistribution across experimental conditions. Application of this framework revealed distinct nanoscale patterns of cholesteryl ester remodeling in Schwann versus MPNST cells under CBD and irradiation, including pronounced spatial reorganization that was not evident from spectral intensities alone. Importantly, the AFM-IR-derived spatial metrics were independently validated by fluorescence lipid droplet staining, demonstrating similar trends between nanoscale infrared measurements and cellular lipid abundance. In parallel, AFM-IR analysis of the Amide I and II regions uncovered CBD-dependent modulation of protein secondary structure, highlighting differential responses between normal and malignant cells. Overall, this study establishes a transferable, pixel-based AFM-IR analysis strategy for nanoscale biochemical semi-quantification and demonstrates its utility in resolving lipid organization and remodeling in complex biological systems.

Nanomaterial-based antibacterial systems offer new opportunities for the control of phytopathogenic bacteria through targeted, multi-level cellular disruption. Herein, this study synthesizes and characterizes the thymol-loaded chitosan nanoparticles (TCNPs) using a variety of physicochemical and antimicrobial efficacy techniques against Xanthomonas oryzae pv. oryzae (Xoo), the causative agent of bacterial leaf blight in rice. Physicochemical characterization confirmed efficient thymol encapsulation, nanoscale particle size, stable surface properties and morphology suitable for bacterial interaction. TCNPs exhibited strong antibacterial activity, reflected in the concentration-dependent reduction of bacterial growth coupled with metabolic viability and its decrease to ~ 60% at sub-lethal concentration (1/2 MIC). Further trypan blue staining revealed a massive increase in membrane-compromised Xoo cells upon TCNPs treatment, an indication of early loss of membrane integrity. Further, the exposure to TCNPs induced oxidative stress as evidenced by the elevated intracellular reactive oxygen species (ROS) and significantly increased lipid peroxidation, as shown by higher malondialdehyde (MDA) levels (44%) at 532nm. Moreover, FTIR analysis demonstrated clear alterations in membrane lipid vibrations, protein secondary structures, and cell-wall carbohydrate regions that confirmed the structural destabilization of Xoo cells. The untargeted LC-MS profiling supported these spectral findings through the loss of intact phospholipids, appearance of oxidized lipid fragments, and depletion of some amino-acid signatures in treated samples. These molecular and biochemical changes together suggest that TCNPs disrupt the bacterial membrane and induce ROS-mediated oxidative damage leading to metabolic imbalance and loss of cell viability. The overall study depicts the multifaceted antibacterial mechanism of TCNPs via membrane destabilization, oxidative lipid damage, and metabolic disruption in Xoo. These findings unravel the potential of TCNPs as a novel nanobiotechnological approach for the sustainable management of rice bacterial leaf blight.

Extracellular polymeric substance (EPS)-mediated biosynthesis is a sustainable route for heavy metal valorization into quantum dots (QDs), yet how the EPS protein secondary structure regulates QD properties remains undefined. Herein, EPS from Shewanella oneidensis MR-1 cultivated under flotation reagent stress was utilized to synthesize high-performance ZnS QDs. Sodium butyl xanthate exhibited the optimal induction effect, significantly lowering the α-helix/(β-sheet + random coil) ratio in EPS. This structural shift promotes a more extended network, serving as a spatially ordered template for rapid, uniform ZnS nucleation. Analyzing QD materials mediated by distinct EPS layers (LB-EPS and TB-EPS) across treatments revealed strong correlations of this ratio with their size uniformity and specific surface area. Conversely, the QD yield and fluorescence intensity were governed primarily by chemical group abundance and synergistic structural-chemical factors, respectively. This dual regulatory mechanism demonstrates that manipulating the EPS protein structure is as crucial as modulating its chemical composition for nanomaterial biosynthesis.

Raman spectroscopic characterization of protein changes induced by 5-fluorouracil in colon cancer cells.

Semaglutide (SMG), a clinically relevant peptide-based therapeutic whose physical and chemical stability are critical concerns during manufacturing and storage. Although the stability of SMG in solution has been extensively studied, its solid-state behaviour remains unclear. This study aimed to systematically evaluate the impact of thermal stress on the solid-state physicochemical stability of SMG. The solid-state stability of SMG was assessed using complementary analytical techniques, including Fourier transform-infrared (FT-IR) spectroscopy, circular dichroism (CD), differential scanning calorimetry (DSC), hot-stage microscopy (HSM), reverse-phase high-performance liquid chromatography (RP-HPLC), and liquid chromatography-high-resolution mass spectrometry (LC-HRMS). FT-IR and CD analyses demonstrated that SMG retains its native α-helical conformation up to 60°C. However, the α-helical content decreased from 49.07% to 43.75% at 60°C and further to 0.2% at 80°C, indicating extensive conformational transitions at elevated temperatures that compromise receptor binding and in vivo performance. DSC and HSM confirmed that SMG remains amorphous under all tested conditions and revealed three major thermal events: residual water loss, enthalpy recovery associated with physical ageing, and thermal decomposition. The overlap of enthalpy recovery with the glass transition phase limited the determination of Tg by conventional DSC; however, modulated DSC enabled the separation of these events, establishing a Tg of 169°C. RP-HPLC and LC-HRMS analyses showed a temperature-dependent degradation and impurity formation. The solid-state stability study identified temperature as a critical factor influencing SMG stability and emphasises the importance of stringent process control in the development of SMG-based formulations.

Degradation sequence, multi-phase distribution, and destabilization mechanisms in anaerobic treatment of real coal chemical wastewater.

46,XY disorders of sexual development (46,XY DSD) are conditions characterized by deviations from typical male sex development, which encompasses a broad spectrum of clinical features such as hypospadias, decreased sperm production, dysgenetic testes, bifid scrotum, and the presence of a mature uterus and fallopian tubes. The WWOX gene, which has been implicated in various cancers, is also thought to play a role in sex development, although its involvement in 46,XY DSD remains poorly understood. This study aimed to investigate the WWOX gene in a patient presenting with hypospadias. A 7-month-old male with a history of in-vitro fertilization pregnancy due to male factor and premature birth was referred to our clinic for hypospadias and undescended testicles. The physical examination showed scrotal hypospadias and significant chordee. Chromosome analysis was 46,XY, and the sex-determining region Y protein was positive. Using DNA sequence analysis and protein expression studies, the p.Ala141Thr variant in the WWOX gene was identified. DNA sequencing analysis revealed that the patient is homozygous for this variant, with the father being homozygous (having an infertility history but no physical examination) and the mother heterozygous for the same mutation. Western blot analysis revealed significantly reduced WWOX protein levels in both the proband and father compared to the healthy controls, indicating that the variant impaired protein expression. These findings were consistent with the results from in-silico analyses, which predicted that the p.Ala141Thr substitution disrupts the secondary structure of the WWOX protein, suggesting a functional impact on its activity.

Protein secondary structure prediction represents an important intermediate step between a protein's linear amino acid sequence and its three-dimensional structure, with broad implications for synthetic biology, drug development, and disease research. Although experimental techniques such as X-ray crystallography provide highly accurate structural information, they are labor-intensive, time-consuming, and costly, which has motivated the development of computational alternatives. Early machine-learning approaches to this problem were limited in their ability to capture complex sequence-structure relationships. The introduction of convolutional and recurrent neural networks improved hierarchical feature extraction, and predictive performance advanced further with transformer-based architectures such as AlphaFold2. This review outlines recent advances in hybrid model design, benchmark datasets, and evaluation metrics for protein secondary structure prediction. We also discuss current methodological limitations, including data dependency and dataset bias, and outline future directions such as cross-species validation, uncertainty-aware modeling, and the still-emerging potential of incorporating heterogeneous biological data into next-generation PSSP frameworks.

Influence of pulsed electric field on rheological and structural properties of frozen non-fermented dough by controlling ice crystal formation.