Current protein & peptide science最新文献

Introduction: Microbial enzymes, especially bacterial alkaline proteases, are essential to many industrial processes, including the manufacturing of detergents, food processing, bioremediation, medicines, and tanneries. Because of its possible industrial benefits, this study focuses on the purification and characterisation of a halophilic alkaline protease generated by Bacillus sp. strain SPII-4.

Methods: The bacteria SPII-4's 16S rRNA gene was sequenced and subjected to phylogenetic analysis. Casein was used as a substrate to measure the extracellular crude enzyme's proteolytic activity. Temperature, pH, salinity, metal ions, and chemical solvents were all used to assess enzymatic activity. Every experiment was run in triplicate, and Student's t-tests with unequal variances in Microsoft Excel were used to assess statistical significance.

Results: The 16S rRNA sequencing matched Bacillus sp. strain 2S4 with 100% identity and 99% coverage. The protease was most active at 40°C, in the alkaline pH range of 9-11, and at concentrations of up to 5% NaCl. The enzyme had the maximum activity (14.64 U/mg) among the metal ions examined when BaCl2 was present. Additionally, it maintained its activity in the presence of the surfactant Triton-X and in a variety of chemical solvents. The observed differences were statistically significant (p < 0.001)

Discussion: The Bacillus SPII-4 protease showed exceptional stability and activity in the presence of surfactants and solvents, as well as in extremely high and low salinity and alkalinity conditions. These characteristics point to the protease's potential for widespread industrial use and are in line with research on related halophilic bacterial enzymes. To maximize its commercial usage, more purification and scale-up research are necessary.

Conclusion: Bacillus sp. SPII-4's halo-alkaline protease exhibits considerable industrial promise because of its stability in conditions that are high in salt, alkalinity, and solvents. These qualities make it a viable option for use in the food, detergent, and pharmaceutical sectors as well as in bioremediation.

Introduction/Objective: This study aimed to evaluate the efficacy of Imunofan, a synthetic peptide adjuvant, compared to Freund's adjuvant. We hypothesized that imunofan would enhance protective immunity while avoiding the adverse effects associated with traditional adjuvants.

Methods: Imunofan (836 Da) was synthesized via SPPS, purified by RP-HPLC, and validated by LC-MS. A chimeric antigen (ESI) encoding EspA, StxB, and Intimin was expressed in E. coli BL21(DE3) using the pET28-ESI plasmid, induced with IPTG, and purified via Ni-NTA chromatography. BALB/c mice (n = 10/group) were immunized with: (1) ESI+Imunofan, (2) ESI+Freund's adjuvant, (3) ESI alone, or (4) Imunofan alone. IgG titers were measured by ELISA, and protection was assessed via bacterial shedding (log10 CFU/g feces) post-challenge with E. coli O157:H7.

Results: ESI+Freund's adjuvant elicited the highest IgG response (mean ± SEM: 12.3 ± 0.8 log10; p < 0.05 vs. ESI alone). Surprisingly, ESI+Imunofan showed a comparable reduction in bacterial shedding (3.1 ± 0.4 log10 CFU/g vs. Freund's adjuvant: 2.9 ± 0.3; p > 0.1), despite lower IgG (9.1 ± 0.6 log10). ESI alone reduced shedding (4.2 ± 0.5 log10; p < 0.01 vs. control), outperforming Imunofan alone (5.8 ± 0.7; p < 0.05).

Conclusion: Imunofan's structural authenticity and functional efficacy were demonstrated. Its comparable protection to Freund's adjuvant, despite weaker humoral responses, suggests a unique role in modulating non-antibody-mediated immunity. These findings support imunofan as a safer alternative to conventional adjuvants.

Collagen is the most abundant structural protein and an essential connective tissue constituent. It plays vital roles in the body and is found in different tissues, including tendons, cartilage, bones, and skin. Collagen is mainly extracted from marine and animal sources (such as fish, cows, pigs, etc.). Synthetic biology platforms have recently gained significant attention by producing non-native collagen substitutes. The multi-purpose uses of collagen and collagen-based products have increased the growing demand for collagen in various industrial applications, including biomedical, food, and cosmetics. The inherent characteristics of collagen, such as its biodegradability, biocompatibility, hemostatic activity, etc., are commonly employed in many biomedical applications. Collagen is widely used in the biomedical industry for drug delivery systems, scaffolds for tissue regeneration, medical devices, bio-inks,etc. It is used in cosmetics for its moisturizing and anti-aging properties. In addition, food-grade collagen is used in many functional foods as a health supplement. The current review describes the collagen's structures, types, and sources. Later, it discusses collagen's versatile applications as a natural biopolymer in biomedical, food, and cosmetic fields.The potential collagen marketand sustainable collagen production with a synthetic biology platform have also been covered.

Introduction: Alzheimer's disease is characterized by a complex and multifactorial pathogenesis, involving key features such as amyloid-beta plaques, tau tangles, and neuron loss. Understanding the disease requires investigating its underlying causes, as these hallmarks reflect the intricate physiological processes involved. Identifying the root factors driving AD is essential for developing effective treatments.

Method: This literature review was conducted using PubMed and Scopus databases, covering studies published from October 1999 to April 2025. The review included 190 references focused on the pathophysiology of Alzheimer's disease (AD). The selected studies analysed the primary pathophysiology leading to AD, particularly the accumulation of amyloid-beta plaques, tau tangles, and neuronal loss.

Result: The study highlights several key biological factors associated with Alzheimer's Disease (AD). These include genetic mutations, mitochondrial dysfunction, hormonal imbalances, inflammation, oxidative stress, cellular division abnormalities, and reduced levels of dopamine-related neurotransmitters. It also highlights issues with calcium regulation and the imbalance of metals, such as copper, iron, lead, and zinc, in the body. Lifestyle choices such as drinking alcohol and smoking, along with changes in blood vessels and problems with the blood-brain barrier, were also found to play a role in how the disease develops. Additionally, the presence of certain pathogens was suggested as a possible factor in the disease's underlying mechanisms.

Discussion: The results indicate that a complex combination of genetic, biochemical, and environmental factors shapes the development and progression of Alzheimer's disease. Genetic mutations seem to play a significant role in affecting enzyme functions, which can disrupt vital biological processes. Problems with mitochondria and hormonal imbalances contribute to the deterioration of nerve cells, while oxidative stress and neuroinflammation are key mechanisms that worsen cellular damage. Disruptions in calcium signalling and imbalances in bio-metals further disturb neuronal stability. Lifestyle choices, blood vessel issues, and blood-brain barrier problems highlight the multifaceted nature of the disease. The study also highlights the close relationship between oxidative stress and neuroinflammation, suggesting that they may form a feedback loop that accelerates disease progression. Additionally, the possible involvement of infectious agents adds another layer of complexity, indicating that infections might trigger or worsen neurodegeneration in vulnerable individuals.

Conclusion: To better understand and address Alzheimer's disease, it is essential to examine the fundamental processes that trigger its development. The various and interconnected factors involved- such as genetic mutations, cellular pr

Introduction: Periodontitis results in progressive loss of gingival tissue and periodontal ligament, eventually resulting in tooth instability. As regenerating degraded periodontal tissue is not possible without intervention, therefore, a tissue-engineered substitute is a good option. Bone regeneration strategies often rely on either biochemical stimulation or engineered scaffolds, but rarely in a coordinated manner. Arginine-Glycine-Aspartic acid (RGD) hydrogel provides a unique combination of biocompatibility and biodegradability, making it an attractive scaffold for tissue engineering. The study aims to investigate the effect of combining Wnt pathway activation with Arginine-Glycine-Aspartic acid (RGD) hydrogel (a three-dimensional environment, 3D) to enhance the osteogenic differentiation of mesenchymal stem cells (MSCs) derived from periodontal ligament tissue.

Methods: The cells were isolated from the root of the extracted tooth. They were grown in an osteogenic medium with and without a Wnt activator in two-dimensional (2D) and RGD hydrogel- based 3D environments to expand in vitro. Osteogenic gene expression was evaluated by qPCR in 2D and 3D cultures. Mesenchymal stem cells isolated from periodontal ligament tissue showed osteogenic differentiation when cultured in a differential medium with or without the Wnt signaling activator, CHIR99021 (a GSK3β inhibitor).

Results: The data of our study revealed that osteogenic genes were expressed in both 2D- and 3D-- cultured cells. However, higher expression of osteogenic genes was found in Wnt signaling-activated cells. Furthermore, the RGD hydrogel provided better differentiation efficacy and a significant increase (p < 0.001) in terms of Wnt-activated differentiation.

Discussion: The RGD hydrogel-Wnt activation model described in this study holds strong potential for translation into preclinical bone regeneration strategies. By enhancing osteogenic differentiation through a synergistic interaction between the Wnt signaling pathway and the 3D peptide hydrogel matrix, this platform offers a promising approach to early-stage testing of bone regeneration therapies.

Conclusion: Hence, the Arg-Gly-Asp (RGD) hydrogel-based 3D microenvironment along with a Wnt signaling activator provides superior efficacy in differentiation since it allows cell encapsulation and an environment that closely simulates native tissues. Therefore, these findings highlight the synergistic effect of biochemical and biophysical cues in directing stem cell fate and offer a promising strategy for advancing stem cell-based bone tissue engineering.

Introduction: Although Doxorubicin (DOX) is an effective anticancer agent, its cardiotoxicity limits clinical use. DOX-induced oxidative stress augments NF-κB expression, elevates inflammatory cytokines, and causes myocardial injury. Since the flavonoid Myricetin (MYR) has antioxidant, anti-inflammatory, and NF-κB-inhibitory properties, we investigated its potential to mitigate DOX-induced cardiotoxicity in rats.

Method: Molecular docking of MYR was performed against NF-κB and proinflammatory cytokines (TNF-α, IL-1β, IL-6). After confirming binding affinities, DOX was administered to rats on days 1, 3, 5, 7, and 9, while MYR was given daily for 9 days. On day 10, hemodynamic parameters were recorded, and blood and heart tissues were collected. Serum transaminases (SGPT, SGOT) and cardiac markers (CK-MB, LDH) were measured. Oxidative stress markers (CAT, SOD, GSH, MDA), proinflammatory cytokines (TNF-α, IL-1β, IL-6), NO, NF-κB levels, and myocardial histopathology were assessed.

Results: MYR exhibited strong binding affinity to target proteins. In vivo, MYR significantly attenuated DOX-induced ECG (ST height) alterations and reduced serum SGPT, SGOT, CK-MB, and LDH levels. In cardiac tissue, MYR enhanced CAT, SOD, and GSH, while reducing MDA. MYR also decreased NF-κB, NO, TNF-α, IL-1β, and IL-6 levels, and improved histopathological features.

Discussion: These findings suggest that MYR effectively counteracts DOX-induced myocardial injury by suppressing NF-κB-mediated inflammatory pathways and oxidative stress, supporting its therapeutic potential in cardioprotection.

Conclusion: MYR mitigates DOX-induced cardiotoxicity through antioxidant and antiinflammatory mechanisms involving inhibition of NF-κB signaling.

Four years ago, at the 14th Critical Assessment of Structure Prediction (CASP14), John Moult made a historic announcement that the long-standing challenge of Protein Structure Prediction- a problem that had confounded scientists for over five decades-had been "solved" for single protein chains. Supporting this groundbreaking statement was a plot depicting the median Global Distance Test (GDT) across 87 out of 92 domains, where AlphaFold2, developed by DeepMind, achieved an unprecedented score of 92.4. The bar chart not only underscored AlphaFold2' s remarkable performance-standing out prominently among other methods-but also revealed a level of accuracy that exceeded all prior expectations. In the years since this breakthrough, DeepMind's team has made significant strides. The AlphaFold Database now hosts approximately 214 million structures for various model organisms, covering nearly the entire genome. Research continues to explore multiple facets of protein science, including the prediction of multi-chain protein complex structures and the impact of missense mutations on protein function. The open availability of this extensive database and the suite of AlphaFold2 algorithms has catalysed remarkable advancements in protein biology and bioinformatics. This review will begin by revisiting DeepMind's early efforts in CASP13, detailing the architecture and the remarkable progress that led to their breakthrough of AlphaFold2 in CASP14 (2020). It will then delve into two main areas: (1) AlphaFold's contributions to the scientific community across various fields over the past four years, and (2) the latest improvements, enhancements, and achievements by DeepMind, including AlphaFold3 and the Nobel Prize in Chemistry.

Protein kinase inhibitors (PKIs) are medicinal substances that target enzymes essential to vital cellular functions by controlling kinase activity. PKIs are being considered as targeted therapeutics to disrupt carcinogenic pathways since dysregulated kinase signalling is a hallmark of cancer. According to their binding mechanisms, PKIs are structurally categorised as follows: Type I inhibitors bind ATP competitively, Type II inhibitors target inactive kinase conformations, Type III inhibitors act through allosteric modulation, Type IV inhibitors operate independently of ATP, and Type V inhibitors, also referred to as covalent inhibitors, create irreversible bonds with target residues. PKIs have shown promise as a treatment for a number of malignancies, including leukemia, melanoma, lung, breast, and kidney cancers. While HER2-targeted PKIs have greatly improved results in breast cancer, targeting EGFR and ALK mutations has enhanced the treatment of lung cancer. Treatments for melanoma target BRAF and MEK inhibitors, while those for renal cell carcinoma concentrate on VEGF and mTOR pathways. Tyrosine kinase inhibitors have made significant strides in treating chronic myeloid leukemia, improving remission rates. Notwithstanding these achievements, resistance mechanisms still pose a threat to the efficacy of treatment, highlighting the necessity of continued investigation into next-generation PKIs and combination approaches to improve clinical outcomes for a range of cancer types. This article provides a comprehensive review of recent advancements in PKI research, including their mechanisms, therapeutic applications, and strategies to overcome drug resistance.

Alzheimer's disease (AD) is a leading cause of dementia worldwide and continues to be one of the most frequently diagnosed neurodegenerative disorders in adults aged 65 and older. While much progress has been made in exploring AD pathophysiology, there remains no current cure, and symptomatic treatment is the current standard at best. As life expectancy continues to rise, the global prevalence of AD is increasing, making it evident that new therapeutic strategies are sorely needed. The etiology of AD is complex and heterogeneous, with cholinergic dysfunction, taurelated dysfunction, amyloid cascade dysfunction, oxidative dysfunction, and neuroinflammation all contributing to the unique pathology. As a result, researchers are focused on safe and effective drug candidates capable of addressing all of these interrelated mechanisms. One group of such multidrug candidates is benzimidazole derivatives, which target numerous molecular targets, such as, but not limited to, cyclin-dependent kinase 5 (CDK5), tau protein, acetylcholinesterase (AChE), betasecretase 1 (BACE1), serotonin receptor 5-HT4, cannabinoid receptor CB2R, and the gammaaminobutyric acid receptor A (GABA-A). This study reveals the multitargeting promise of benzimidazole- based compounds that regulate not just symptomatic pathways but also pathways that are responsible for modifying AD disease activity. Ongoing studies in this area may lead to the discovery of new drugs that can not only manage the symptoms but also change the trajectory of this serious disease and provide hope to millions of AD patients.