Chain Degradation Research Articles

Improvement on gel properties of chicken myofibrillar protein with electron beam irradiation: Based on protein structure, gel quality, water state

This study aimed to investigate the effects of electron beam (E-beam) irradiation at different doses (0–15 kGy) on the solubility, rheological properties, emulsification characteristics, and moisture distribution of chicken myofibrillar proteins (MPs). Irradiation treatment notably increased the solubility, surface hydrophobicity, emulsification properties, and apparent viscosity of MPs, based on conformational changes caused by irradiation-induced oxidative denaturation of proteins. However, high doses of irradiation (15 kGy) induced in excessive cross-linking and aggregation of proteins, reducing the solubility, emulsification properties, and shear stress. Degradation of myosin heavy and light chains in irradiated MPs increased the content of β-turns and random coils. Additionally, the initial relaxation times of T21 and T22 in irradiated protein gels were reduced, and the peak value of P21 was increased, which improved the water-capturing ability of protein gels. Altogether, these results findings suggest that electron beam irradiation can be applied as a potential technique for modifying muscle proteins.

Rheological analysis of network structure of raw natural rubber prepared by different processing techniques

The performance of raw natural rubber (NR) is dominated by its network structure, particular the levels of long chain branching (LCB) and entanglement. Here, three type of raw rubbers were prepared using different processing methods for commercial grade NRs. Linear and nonlinear viscoelastic behaviors, as well as stress relaxation, were analyzed to access their network structures. The third relative harmonic, phase angle, and first to second quarter-period integral ratio of stress curve were utilized as indicators for the nonlinearity of samples. By combining these values with flow activation energy and characteristic times, it can be confirmed that naturally coagulated NR showed higher elasticity than acid-coagulated NR due to high levels of LCB and entanglement, and hot air drying could lead to chain degradation. These findings correlated with molecular weight parameters, gel content and Mooney viscosity results. This research establishes a method for monitoring raw NR quality and predicting its properties.

Hemoglobin α-derived peptides VD-hemopressin (α) and RVD-hemopressin (α) are involved in electroacupuncture inhibition of chronic pain.

Knee osteoarthritis (KOA) is a chronic degenerative bone metabolic disease that primarily affects older adults, leading to chronic pain and disability that affect patients' daily activities. Electroacupuncture (EA) is a commonly used method for the treatment of chronic pain in clinical practice. Previous studies indicate that the endocannabinoid system is involved in EA analgesia, but whether endocannabinopeptide VD-hemopressin (α) and RVD-hemopressin (α) derived from hemoglobin chains are involved in EA analgesia is unclear. RNA-seq technology was used to screen which genes involved in EA analgesia. The expression of hemoglobin α chain and 26S proteasome were determined by Western blotting. The level of VD-hemopressin (α) and RVD-hemopressin (α) were measured by UPLC-MS/MS. Microinjection VD-Hemopressin (α), RVD-Hemopressin (α) and 26S proteasome inhibitor MG-132 into vlPAG, then observe mechanical and thermal pain thresholds. Therefore, we used RNA-seq to obtain differentially expressed genes Hba-a1 and Hba-a2 involved in EA analgesia in the periaqueductal gray (PAG), which were translated into the hemoglobin α chain. EA significantly increased the expression of the hemoglobin α chain and the level of hemopressin (α) and RVD-hemopressin (α). Microinjection of VD-hemopressin (α) and RVD-hemopressin (α) into the ventrolateral periaqueductal gray (vlPAG) mimicked the analgesic effect of EA, while CB1 receptor antagonist AM251 reversed this effect. EA significantly increased the expression of 26S proteasome in KOA mice. Microinjection of 26S proteasome inhibitor MG132 before EA prevented both the anti-allodynic effect and upregulation of the concentration of RVD-hemopressin (α) by EA treatment and upregulated the expression of the hemoglobin α chain. Our data suggest that EA upregulated the concentration of VD-hemopressin (α) and RVD-hemopressin (α) through enhancement of the hemoglobin α chain degradation by 26S proteasome in the PAG, then activated the CB1 receptor, thereby exerting inhibition of chronic pain in a mouse model of KOA. These results provide new insights into the EA analgesic mechanisms and reveal possible targets for EA treatment of chronic pain.

Pressure-induced formability and degradability of block copolymers composed of poly(1,5-dioxepan-2-one) and poly(L-lactide)

An aliphatic polyether/carbonate block copolymer, comprising poly(1,5-dioxepan-2-one) (PDXO, glass transition temperature Tg: -38°C) and poly(L-lactide) (PLLA, Tg: 55°C), evinces remarkable formability under pressure at temperatures significantly below the melting point of PLLA. A quantitative and detailed evaluation of the low-temperature molding of the block copolymer was conducted using a capillary rheometer. The findings reveal that block copolymers with PDXO composition >55 wt% demonstrate a propensity to flow at room temperature under 50 MPa pressure. Consequently, the practice of low-temperature molding serves to mitigate the degradation of polymer chains during the molding process, thereby augmenting recyclability. Furthermore, the enzymatic degradability of the block copolymer was extensively investigated using lipase PS and proteinase K. An interplay between the structure of the block copolymer and the degradation kinetics was explored. The polymeric materials developed, possessing both pressure formability and degradability, hold promising potential as environmentally benign polymers with reduced environmental impact.

Atomic scale investigation and cytocompatibility of copper and zinc-loaded phosphate-based glasses prepared by coacervation

Phosphate-based glasses (PBGs) are bioresorbable materials that find application in the field of controlled drug delivery and tissue engineering. The structural arrangements of the phosphate units in PBGs, along with the knowledge of how therapeutic metallic ions are embedded in the phosphate network are important in understanding the degradation and targeted release properties of these materials. Using a combination of Raman spectroscopy, high-energy X-ray diffraction and 31P and 23Na solid-state magic angle spinning nuclear magnetic resonance, the atomic structure of coacervate PBGs in the system P2O5-CaO-Na2O-MOx (M = Cu or Zn) with loadings of 2, 10 and 15 mol % of M2+ have been studied as functions of composition and calcination temperature. After drying at room temperature, the structures of the phosphate network in PBG-Cu and PBG-Zn are quite similar, with that of PBG-Zn exhibiting slightly higher connectivity. Heating at 300 °C causes degradation of the polyphosphate chains, even though Q2 species remain predominant. X-ray photoelectron spectroscopy demonstrates that Cu in calcined PBGs is present in both oxidation states +1 and +2, with a predominance of the +2 state. Cu and Zn ion release data after 24 h exposure of PBGs in deionized water and cell medium DMEM show that release is proportional to their loadings. Cytotoxicity MTT assays of dissolution products of PBG-Cu/ZnX calcined at 300 °C on human osteosarcoma cells (MG-63) and on human skin cells (HaCaTs) showed good cellular response for all compositions, indicating that PBGs have great potential for both hard and soft tissue regeneration.

Recycling of EPDM rubber via thermomechanical devulcanization: Batch and continuous operations

Thermomechanical devulcanization is a possible solution for the circular economy of EPDM rubber, as it removes covalent crosslinks from vulcanizates, resulting in a material similar to uncured rubber mixes. In this paper, sulfur-cured EPDM rubber was treated with thermomechanical stimuli: a) processing on a two-roll mill and in an internal mixer, and b) twin-screw extrusion. Horikx's analysis indicated a 75 % decrease in crosslink density with little polymer chain degradation. The resulting devulcanizates and non-devulcanized rubber crumb were added to the original rubber mix, yielding samples with 0, 25, 50, 75 and 100 wt% recycled rubber contents. Revulcanizates with up to 50 wt% devulcanizate content retained the tensile strength of the original rubber with a slight increase in modulus. Ultimately, batch devulcanization had the most promising results, and extrusion devulcanization was also more beneficial than using non-devulcanized rubber crumb. Crosslink density and morphological tests also support these findings.

Suspected poor-quality medicines in Kenya: a retrospective descriptive study of medicine quality-related complaints reports in Kenya’s pharmacovigilance database

Poor-quality, substandard and falsified, medicines pose a significant public health threat, particularly in low-middle-income countries. A retrospective study was performed on Kenya's Pharmacovigilance Electronic Reporting System (2014–2021) to characterize medicine quality-related complaints and identify associations using disproportionality analysis. A total of 2767 individual case safety reports were identified, categorized into medicines with quality defects (52.1%), suspected therapeutic failure (41.6%), and suspected adverse drug reactions (6.3%). Predominantly reported were antineoplastic agents (28.6%), antivirals (11.7%), and antibacterial agents (10.8%) potentially linked to non-adherence to good manufacturing practices, inappropriate usage and supply chain degradation. Notably, analgesics (8.2%), and medical devices (3.5%) notified had quality defects, predominantly from government health facilities (60.0%). Antineoplastic agents (20.2%) and antivirals (3.7%) were frequently reported from suspected therapeutic failures and suspected adverse drug reactions, respectively, across both private for-profit facilities (26.5%) and not-for-profit facilities (5.4%). Underreporting occurred in unlicensed health facilities (8.1%), due to unawareness and reporting challenges. Pharmacists (46.1%), and pharmaceutical technicians (11.7%) predominantly reported quality defects, while medical doctors (28.0%) reported suspected therapeutic failures. Orally administered generic medicines (76.9%) were commonly reported, with tablets (5.8%) identified as potential sources of suspected adverse drug reactions, while quality defects were notified from oral solutions, suspensions, and syrups (7.0%) and medical devices (3.9%). The COVID-19 pandemic correlated with reduced reporting possibly due to prioritization of health surveillance. This study provides valuable evidence to supporting the use of medicine quality-related complaints for proactive, targeted regulatory control of high-risk medicines on the market. This approach can be strengthened by employing standardized terminology to prioritize monitoring of commonly reported suspected poor-quality medicines for risk-based sampling and testing within the supply chain.

A cross-level vibration prediction of USM stator under electron radiation

Moving components exposed to electron radiation over longer durations are more prone to failure due to its complex changes from material properties to component characteristics. It involves multi-scale analysis, leading to current methods being deficient in accuracy and efficiency. In this paper, a cross-level vibration prediction method, which selects the ultrasonic motor (USM) stator as a typical component for Jupiter exploration, is proposed by incorporating the cross-scale changes of material properties based on the edge-based smoothed finite element method (ES-FEM). A cross-scale degradation model for exploring the material properties is constructed by establishing the correlation between the degradation of molecular chains and the mechanical properties of the epoxy resin. The ES-FEM is developed for investigating the vibration of the USM stator, by introducing the edge-based gradient smoothing technique (GST) to perform the strain smoothing operation in its stiffness matrix, offering superior accuracy and efficiency. The experiment of 1.2 MeV electron radiation under different electron fluences was carried out. It demonstrated that the present method can achieve higher accuracy and efficiency than the traditional one, while being closed to the experimental results with the frequency and amplitude errors of 0.03 % and 1.3 %, respectively.

Evaluation and Comparison of Force Degradation Levels Between Elastomeric Chains and Active Tiebacks With Elastic Modules During Individual Canine Retraction.

Canine retraction is critical in orthodontic treatment, requiring precise force application. Elastomeric chains and active tiebacks are commonly used materials, but their efficacy in maintaining the force over time needs further evaluation. The study aimed tocompare the rate of force degradation of elastomeric chains vs. active tiebacks during canine retraction overa duration of six weeks in patients undergoing fixed orthodontic therapy. This study involved 20 patients, aged between 16 and 25 years. All the subjects were treated with the 0.018" McLaughlin-Bennett-Trevisi (MBT) prescription. Following the initial leveling and alignment, the canines were retracted on 0.016 x 0.022" stainless steel wire, using an elastomeric chain (ORMCO) on one side and an active tieback (ORMCO)on the contralateral side, each exerting a force of 150 g. Force values were measured using a tension gauge (TECLOCK; DT- 300) at intervals of 48 hours, two weeks, four weeks, and six weeks by a single observer and documented accordingly. The elastomeric chainandactive tieback sides demonstrated substantial force degradation oversix weeks, with a marked reduction of force at given intervals. However, no statistically significant difference in force degradation rates was observed between the two methods (p> 0.05), indicating similar force degradation patterns. The elastomeric chainand active tieback methods demonstrated substantial force degradation over six weeks, with no statistically significant difference between the two. Thus, both materials can be effectively utilized for canine retraction in orthodontic treatmentas they exhibit similar patterns of force degradation.

Facile and Low‐Cost Electrochemical Synthesis of Zinc Alginate Hydrogel Films for Biomedical Applications

ABSTRACTElectrochemical synthesis and characterization of Zn‐alginate hydrogel films and their antioxidant and antimicrobial activity are evaluated. Swelling properties, zinc concentration and spectroscopic and morphological features were characterized and related to their antimicrobial and antioxidant activity. These results indicate a dependence of swelling on the degree of cross‐linking, which, in turn, can be adjusted by manipulating the synthesis time, initial alginate concentration and/or zinc leaching. Hydrogel films with zinc showed remarkable antibacterial properties, especially against gram‐positive bacteria. The absence of Zn resulted in less inhibition of gram‐positive strains, although it had a positive effect on the inhibition of gram‐negative strains, which was attributed to the degradation of alginate chains, affecting cell metabolism. Nitrogen‐doped samples synthesized in rivanol‐containing solution exhibited globular morphology and higher antioxidant activity. The electrochemical synthesis enables the facile preparation of highly active alginate hydrogels for biomedical applications.

Multi-Sensitive Au NCs/5-FU@Carr-LA Composite Hydrogels for Targeted Multimodal Anti-Tumor Therapy.

Multifunctional targeted drug delivery systems have been explored as a novel cancer treatment strategy to overcome limitations of traditional chemotherapy. The combination of photodynamic therapy and chemotherapy has been shown to enhance efficacy, but the phototoxicity of traditional photosensitizers is a challenge. In this study, we prepared a multi-sensitive composite hydrogel containing gold nanoclusters (Au NCs) and the temperature-sensitive antitumor drug 5-fluorourac il (5-FU) using carboxymethyl cellulose (Carr) as a dual-functional template. Au NCs were synthesized using sodium borohydride as a reducing agent and potassium as a promoter. The resulting Au NCs were embedded in the Carr hydrogel, which was then conjugated with lactobionic acid (LA) as a targeting ligand. The resulting Au NCs/5-FU@Carr-LA composite hydrogel was used for synergistic photodynamic therapy (PDT), photothermal therapy (PTT), and chemotherapy. Au NCs/5-FU@Carr-LA releases the drug faster at pH 5.0 due to the acid sensitivity of the Carr polymer chain. In addition, at 50 °C, the release rate of Au NCs/5-FU@Carr-LA is 78.2%, indicating that the higher temperature generated by the photothermal effect is conducive to the degradation of Carr polymer chains. The Carr hydrogel stabilized the Au NCs and acted as a matrix for drug loading, and the LA ligand facilitated targeted delivery to tumor cells. The composite hydrogel exhibited excellent biocompatibility and synergistic antitumor efficacy, as demonstrated by in vitro and in vivo experiments. In addition, the hydrogel had thermal imaging capabilities, making it a promising multifunctional platform for targeted cancer therapy.

Nanocomposite polyphenyleneoxide with amino-functionalized silica: structural characterization based on thermal analysis

AbstractA polymer nanocomposite based on sulfonated polyphenylene oxide with amino-functionalized mesoporous silica was designed, synthesized, and tested as a new material for proton exchange membrane (PEM preparation. Characterization of the intermediate and final products of synthesis was realized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and thermal analysis. Broadband Dielectric Spectroscopy (BDS) was used to determine dielectric properties including ionic conductivity. Thermogravimetric analysis has provided important information regarding the composition and thermal stability of the three compounds, subject to thermal degradation: 1) the amino-silica with cetyltrimethylammonium bromide (CTAB) template inside the pores (MS-NH2I), 2) the mesoporous amino-silica after removing the template (MS-NH2II) and 3) the polymer nanocomposite (sPPO-MS-NH2). The thermal decomposition of the composite samples occurs in three stages: in the first, up to 150 °C, water and organic solvents were lost; the second stage, between 200-300 °C, was due to breaking the organic functionalities (-NH2, amino and -SO3H, sulfonic acid), and the third stage, above 400 °C was due to polymer chain degradation. The final residue at 700 °C reflects the contribution of inorganic silica. The proton conductivity, for polymeric (sPPO) and composite (sPPO-MS-NH2) membranes was determined from BDS dates, both in dry and hydrated states. For dried samples, the higher values of proton conductivities were: 0.16 mS cm−1 (sPPO, 70 °C) and 0.03 mS cm−1 (sPPO-MS-NH2, 120 °C), and the higher values of proton conductivity increased for the hydrated samples with two orders of magnitude: 36.5 mS cm−1 (sPPO, 40 °C) and 22.4 mS cm−1 (sPPO-MS-NH2, 50 °C). However, the proton conductivity is still dependent on the hydration state, even for the composite membrane.

Degradation strategies for structural characterization of insoluble synthetic polymers by mass spectrometry.

With the advent of soft ionization techniques such as electrospray (ESI) and matrix-assisted laser desorption/ionization (MALDI) to produce intact gas-phase ions from nonvolatile macromolecules, mass spectrometry has become an essential technique in the field of polymeric materials. However, (co)polymers of very high molecular weight or with reticulated architectures still escape ESI or MALDI, mainly due to solubility issues. Strategies developed to tackle such an analytical challenge all rely on sample degradation to produce low-mass species amenable to existing ionization methods. Yet, chain degradation needs to be partial and controlled to generate sufficiently large species that still contain topological or architectural information. The present article reviews the different analytical degradation strategies implemented to perform mass spectrometry of these challenging synthetic polymers, covering thermal degradation approaches in sources developed in the 2000s, off-line sample pre-treatments for controlled chemical degradation of polymeric substrates, and most recent achievements employing reactive ionization modes to perform chemolysis on-line with MS.

Addition of olive by-product extracts to sunflower oil: Study by 1H NMR on the antioxidant effect during potato deep-frying and further in vitro digestion

Potatoes were fried in sunflower oil enriched or not with Chetoui olive by-product extracts (leaves and olive mill wastewater), and afterwards submitted to in vitro gastrointestinal digestion. Frying oils and fried potato lipids before and after digestion were analyzed using proton Nuclear Magnetic Resonance (1H NMR) spectroscopy. Potential differences on lipid composition, oxidative status and after digestion also lipolysis degree, were studied. During deep-frying with oil replenishment, a higher generation of aldehydes was observed in non-enriched oils. During digestion, in the lipids of digested potatoes fried in non-enriched oil a higher degradation of linoleic chains and a higher generation of cis,trans-hydroperoxy- and cis,trans-hydroxy-octadecadienoates (primary oxidation compounds) and of alkanals was observed. A slightly higher lipolysis degree was reached in the lipids of potatoes fried in enriched oils. These findings suggest that the addition of both extracts could exert a potential antioxidant effect during frying and digestion, enhancing the quality, safety and nutritional value of fried food.

The Degradation of Botulinum Neurotoxin Light Chains Using PROTACs.

Botulinum neurotoxins are some of the most potent natural toxins known; they cause flaccid paralysis by inhibiting synaptic vesicle release. Some serotypes, notably serotype A and B, can cause persistent paralysis lasting for several months. Because of their potency and persistence, botulinum neurotoxins are now used to manage several clinical conditions, and there is interest in expanding their clinical applications using engineered toxins with novel substrate specificities. It will also be beneficial to engineer toxins with tunable persistence. We have investigated the potential use of small-molecule proteolysis-targeting chimeras (PROTACs) to vary the persistence of modified recombinant botulinum neurotoxins. We also describe a complementary approach that has potential relevance for botulism treatment. This second approach uses a camelid heavy chain antibody directed against botulinum neurotoxin that is modified to bind the PROTAC. These strategies provide proof of principle for the use of two different approaches to fine tune the persistence of botulinum neurotoxins by selectively targeting their catalytic light chains for proteasomal degradation.

Mitigating chain degradation of lithium-rich manganese-based cathode material by surface engineering

Due to offering joint cationic and anionic redox, lithium-rich manganese-based layered oxides (LMLOs) allow high energy density in lithium-ion batteries. However, the oxygen loss, electrode-electrolyte interface side reactions and the structural degradation have resulted in continuous performance decay, hindering the scale-up application of LMLOs. Here, Li1.3V0.94(BO3)2 (LVB) is uniformly coated on the Li1.2Mn0.54Co0.13Ni0.13O2 (LMNCO) surface by using a sol-gel method combined with a high-temperature calcination. By applying multiple characterizations including in-situ XRD, DEMS, HRTEM, AFM and electrochemical test, we prove that the LVB layer provides a physical barrier, which effectively inhibits the surface reactivity and blocks the chain degradation from the source, improves the reversibility of O2- redox and prevents the phase transition and structural degradation propagating from the surface to the bulk. Moreover, the kinetic investigations and calculations reveal that the LVB modification not only improves the electron conductivity of materials by decreasing the surface work function and increasing the electron density near the Fermi energy level, but also provides expanded pathways with lower impedance to facilitate the Li+ transfer and diffusion. Impressively, the modified cathode exhibits the higher rate performance (151 mAh g-1 at 5C) and improved cycle stability under high cutoff voltage (217.7 mAh g-1 after 200 cycles at 0.2C in 2.0–4.8 V, 92.5 % capacity retention; even in 2.0–5 V, 93.9 % after 100 cycles). This work systematically investigates the inhibiting degradation mechanism and establishes the correlation between the intrinsic structure and surface engineering, and offers valuable insight into the development of high-performance LMLOs.

GAMMA IRRADIATION – A METHOD OF RECYCLING POLYMERIC MATERIALS

Radiation processing of polymers has many technical and environmental advantages. The low pollution and low energy consumption of radiation processing of polymers, along with its potential in polymer recycling makes it a green technology. Modification in polymeric structure of plastic material can be brought either by conventional chemical means or by exposure to ionization radiation. During the irradiation process the following phenomena occurs: chain branching, cross-linking, degradation or cleavage. These phenomena coexist and depend on several factors such as the initial molecular structure and morphology of the polymer and the irradiation environment i.e. irradiation dose, irradiation dose rate, presence or absence of oxygen. This paper provides an overview of the polymer recycling possibilities using gamma irradiation.

Shy is a proteobacterial steroid hydratase which catalyzes steroid side chain degradation without requiring a catalytically inert partner domain

Shy (side chain hydratase) and Sal (side chain aldolase), are involved in successive reactions in the pathway of bile acid side chain catabolism in Proteobacteria. Untagged Shy co-purified with His-tagged Sal indicating that the two enzymes form a complex. Shy contains a MaoC and a DUF35 domain. When co-expressed with Sal, the DUF35 domain but not the MaoC domain of Shy was observed to co-purify with Sal, indicating Sal interacts with Shy through its DUF35 domain. The MaoC domain of Shy (ShyMaoC) remained catalytically viable and could hydrate cholyl-enoyl-CoA with similar catalytic efficiency as in the Shy-Sal complex. Sal expressed with the DUF35 domain of Shy (Sal-ShyDUF35) was similarly competent for the retroaldol cleavage of cholyl-3-OH-CoA. ShyMaoC showed a preference for C5 side chain bile acid substrates, exhibiting low activity towards C3 side chain substrates. The ShyMaoC structure was determined by X-ray crystallography, showing a hot dog fold with a short central helix surrounded by a twisted anti-parallel β-sheet. Modeling and mutagenesis studies suggest that the bile acid substrate occupies the large open cleft formed by the truncated central helix and repositioning of the active site housing. ShyMaoC therefore contains two substrate binding sites per homodimer, making it distinct from previously characterized MaoC steroid hydratases that are (pseudo)-heterodimers with one substrate binding site per dimer. The characterization of Shy provides insight into how MaoC family hydratases have adapted to accommodate large polycyclic substrates that can facilitate future engineering of these enzymes to produce novel steroid pharmaceuticals.

In-vitro and in-silico analyses of the thrombolytic potential of green kiwifruit

Cardiovascular diseases (CVDs), mainly caused by thrombosis complications, are the leading cause of mortality worldwide, making the development of alternative treatments highly desirable. In this study, the thrombolytic potential of green kiwifruit (Actinidia deliciosa cultivar Hayward) was assessed using in-vitro and in-silico approaches. The crude green kiwifruit extract demonstrated the ability to reduce blood clots significantly by 73.0 ± 1.12% (P < 0.01) within 6 h, with rapid degradation of Aα and Bβ fibrin chains followed by the γ chain in fibrinolytic assays. Molecular docking revealed six favorable conformations for the kiwifruit enzyme actinidin (ADHact) and fibrin chains, supported by spontaneous binding energies and distances. Moreover, molecular dynamics simulation confirmed the binding stability of the complexes of these conformations, as indicated by the stable binding affinity, high number of hydrogen bonds, and consistent distances between the catalytic residue Cys25 of ADHact and the peptide bond. The better overall binding affinity of ADHact to fibrin chains Aα and Bβ may contribute to their faster degradation, supporting the fibrinolytic results. In conclusion, this study demonstrated the thrombolytic potential of the green kiwifruit-derived enzyme and highlighted its potential role as a natural plant-based prophylactic and therapeutic agent for CVDs.

Effects of ultrasonic-assisted marinating on degradation of beef protein and formation of flavor precursors

In the process of meat production, marinating has a great influence on the flavor of the final product. In this study, the effect of ultrasound-assisted dry-marinating on protein degradation, structural changes, and formation of flavor precursor substances were investigated for 12 h and 24 h. The increase in protein degradation index and protease activities under ultrasound promoted the production of free amino acids. After sonication, the microstructure of muscle tissue was loose, and the relative content of β-turn and β-sheet were reduced, indicating that ultrasonic treatment facilitated the oxidation and hydrolysis of proteins. The increased proteolysis could be reflected in increased degradation of myosin light chains and troponin-T. It’s worth noting that ultrasonic-assisted dry-marinating 90 min and continued static marinating until 12 h could achieve the treatment of static marinating for 24 h. These results indicated that ultrasound-assisted dry-marinating could effectively improve the marinating efficiency by promoting protein degradation, affecting the formation of flavor precursors in meat.