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The formation of natural gas hydrates presents significant economic and safety challenges to the petroleum and gas industry, necessitating the development of effective prevention strategies. This study investigates an environmentally sustainable Tenebrio molitor antifreeze protein (TmAFP) modified to be a potential kinetic hydrate inhibitor. The aim of this study was to enhance the inhibitory activity of TmAFP by systematically substituting threonine (Thr) residues with glycine (Gly), alanine (Ala), or serine (Ser) at positions 29, 39, and 53. The Ala mutant demonstrated superior inhibition of hydrate formation, attributed to its optimized spatial conformation and enhanced hydrophobic interactions, followed by the Gly and Ser mutants. The wild-type TmAFP showed limited efficacy. The radial distribution function (RDF) analysis indicated that the mutations facilitated a better accommodation of adjacent residues within the hydrate crystal structure by adjusting the distance between Thri and Thri+2 to closely match the second peak in the RDF of methane molecules at 6.4 Å. The potential of mean force (PMF) calculations revealed that the Ala and Ser mutants exhibited enhanced interactions with hydrate cages, with PMF values of −0.73 and −0.71 kJ/mol, respectively, compared to the Gly mutant, which had a PMF value of 1.46 kJ/mol. By identifying the optimal mutation combination (T29 39 53A) to significantly increase the potency of TmAFP, this study provides a fundamental basis for the further development of hydrate inhibition strategies. [ABSTRACT FROM AUTHOR]

Sperm cryopreservation is crucial in reproductive biotechnology; however, the longevity of frozen and thawed semen is limited by the deterioration of sperm cell integrity. This study aimed to examine the effects of adding antifreeze protein III (AFP III) to the diluent, using samples from eight healthy mature dogs. The ejaculates were divided into aliquots and diluted with a standard Tris-fructose-egg yolk extender containing AFP III at concentrations of 0, 0.75, 1.0, and 2.0 μg/ml. After thawing, the samples were analyzed for kinematic parameters, membrane Integrity, lipid peroxidation, viability, acrosome integrity, intracellular hydrogen peroxide, mitochondrial membrane potential and apoptotic metrics. The results show that while motility and velocity were not significantly different between the treated and control groups (p > 0.05), the treated groups generally performed better. Specifically, the 0.75 and 1.0 μg/ml groups exhibited better movement compared to the 2.0 μg/ml group. Additionally, there was a significant difference (p < 0.05) in membrane integrity between the control and treated groups, though no differences were observed among the treated groups. Significant differences (p < 0.05) were also observed in viability and acrosome integrity, with the 0.75 and 1.0 μg/ml groups outperforming the control and 2.0 μg/ml groups. There were no significant variations (p > 0.05) in phosphatidylserine translocation, lipid peroxidation, mitochondrial membrane potential, or hydrogen peroxide levels. However, the 0.75 and 1.0 μg/ml groups demonstrated superior effects compared to both the control and the 2.0 μg/ml groups. These results suggest that the addition of antifreeze proteins, specifically AFP III, markedly improves the protection of canine sperm during cryopreservation. This enhancement is evident in various parameters, underscoring the beneficial effects of AFP III in maintaining sperm quality. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigated the effects of MitoQ and antifreeze protein III (AFP III) on the frozen and thawed semen of dogs. The samples were mixed with solutions containing MitoQ (200 nM/mL) and AFP III (0.75, 1.0, and 2.0 µg/mL). After thawing, we observed significant improvements in sperm movement and structure with AFP III and MitoQ. AFP III also improved sperm viability and membrane integrity, especially at 0.75 and 1.0 µg/mL concentrations. There were no significant changes in ROS-H2O2 levels or mitochondrial function, except in the 1.0 µg/mL AFP III group. The combined treatment with MitoQ and AFP III significantly reduced dead sperm cells. In conclusion, AFP III and MitoQ can protect canine sperm from cryodamage. Cryopreservation can adversely affect sperm motility, structural integrity, and fertilization ability. This study investigated the effects of MitoQ and antifreeze protein III (AFP III) on frozen–thawed semen from eight adult dogs using a Tris–fructose extender. Ejaculates were divided and diluted with a standard Tris–fructose–egg yolk extender containing MitoQ (200 nM/mL) and AFP III (0.75, 1.0, 2.0 µg/mL), individually or combined. Post-thaw, samples were evaluated for motility, viability, membrane and acrosome integrity, lipid peroxidation, apoptosis indicators, mitochondrial function, and reactive oxygen species (ROS-H2O2). The results showed significant (p < 0.05) improvements in motility rate, progressive motility, VAP, VSL, VCL, ALH, and BCF with MitoQ or AFP alone. AFP III (0.75, 1.0 µg/mL) showed higher values than controls (p > 0.05), while MitoQ alone showed no significant effect. Viability and acrosome integrity improved with AFP III. Membrane integrity and lipid peroxidation were better in 0.75 and 1.0 µg/mL AFP III groups. ROS-H2O2 levels and mitochondrial membrane potential were unaffected except at 1.0 µg/mL AFP III. The phosphatidylserine translocation assay showed no significant differences in dead sperm between controls and individual treatments, but significant differences occurred with combined MitoQ/AFP III. In conclusion, AFP III and MitoQ in diluents protect canine sperm cells from cryodamage. [ABSTRACT FROM AUTHOR]

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The effects of antifreeze proteins (AFP) on the quality changes of pork during freezing were investigated in comparison to those of the commercial antifreeze agent alginate (4 mg/mL). Samples with no added AFP were used as a control. The effects of adding different amounts of AFP (0.05, 0.1, 0.2, and 0.3 mg/mL) on the quality, physicochemical properties of myofibrillar proteins, microstructure, and water distribution of frozen pork were investigated. The results showed that AFP decreased the water loss of frozen pork, which was beneficial to maintaining pork color and microstructure. Addition of AFP at 0.3 mg/mL had the highest cryoprotective effect on the cooking loss, thawing loss and color characteristics of pork during frozen storage, followed by AFP at 0.2 mg/mL and alginate at 4 mg/mL. The shear force and total sulfhydryl content of myofibrillar proteins in the 0.2 and 0.3 mg/mL AFP groups were significantly higher than those of the control group (P < 0.05). nuclear magnetic resonance imaging (NMRI) discovered that the infiltration of AFP reduced the loss of bound and immobile water in pork. Scanning electron microscopy showed that in the presence of 0.2 mg/mL AFP, the arrangement of muscle fibers was orderly, appearing more compact and denser. Overall, AFP addition had a positive effect on improving the quality of frozen pork and might have the potential of being a safe and efficient cryoprotection method.

The polar regions hold immense ecological and historical significance, offering insights into biomarker identification, climate history, and natural antifreeze proteins. However, global climate change and scattered datasets threaten effective research in these areas. To address these challenges, we developed PolarBytes, a centralized platform for polar research, focusing on biodiversity, climatology, diseases, and molecular biology. PolarBytes streamlines data access, analysis, and visualization through an intuitive interface and advanced machine learning tools. Its robust API system, including RESTful and Swagger interfaces, eliminates manual downloads, supports automation, and enhances research efficiency. By centralizing data from isolated repositories, PolarBytes simplifies data retrieval and fosters collaboration, enabling researchers to focus on scientific exploration rather than technical hurdles. This user-friendly platform empowers the scientific community to uncover new insights and drive innovation in understanding polar ecosystems and their global impact. • PolarBytes centralizes reliable polar research data to enhance accessibility and utility for polar scientist. • PolarBytes offers clean datasets and interactive visualizations, simplifying complex data. • PolarBytes feature four categories of datasets; biodiversity, climatology, disease, and molecular biology. • PolarBytes provides two types of APIs: RESTful API and Swagger API, ensuring efficient and flexible data access. • All dataset are validated, reliable, and ideal for research and educational purposes. [ABSTRACT FROM AUTHOR]

Prediction of antifreeze proteins (AFPs) holds significant importance due to their diverse applications in healthcare. An inherent limitation of current AFP prediction methods is their reliance on unreviewed proteins for evaluation. This study evaluates, proposed and existing methods on an independent dataset containing 80 AFPs and 73 non-AFPs obtained from Uniport, which have been already reviewed by experts. Initially, we constructed machine learning models for AFP prediction using selected composition-based protein features and achieved a peak AUROC of 0.90 with an MCC of 0.69 on the independent dataset. Subsequently, we observed a notable enhancement in model performance, with the AUROC increasing from 0.90 to 0.93 upon incorporating evolutionary information instead of relying solely on the primary sequence of proteins. Furthermore, we explored hybrid models integrating our machine learning approaches with BLAST-based similarity and motif-based methods. However, the performance of these hybrid models either matched or was inferior to that of our best machine-learning model. Our best model based on evolutionary information outperforms all existing methods on independent/validation dataset. To facilitate users, a user-friendly web server with a standalone package named "AFPropred" was developed (https://webs.iiitd.edu.in/raghava/afpropred)., (© 2024 Wiley‐VCH GmbH.)

Organisms that survive at freezing temperatures produce antifreeze proteins (AFPs) to manage ice nucleation and growth. Inspired by AFPs, a series of synthetic materials have been developed to mimic these proteins in order to avoid the limitations of natural AFPs. Despite their great importance in various antifreeze applications, the relationship between structure and performance of AFP mimics remains unclear, especially whether their molecular charge-specific effects on ice inhibition exist. Herein, we design the AFP mimics─charged graphene oxide (GO) nanosheets─grafted with positive charge, negative charge, and zwitterionic groups, respectively. The relationship between the GO charge structure and antifreeze performance is investigated, and the distinct efficiency of charge in ice inhibition is systematically discovered. Based on the best-performing zwitterionic GO nanosheets, a highly efficient anti-icing and deicing coating is created. Moreover, benefiting from the photothermal property of GO nanosheets, the microstructures of coating are constructed to further enhance solar thermal deicing performance.